Abstract:
An apparatus for mounting optical components and adjusting its orientation with respect to the optical axis of other components in an optical system. In one embodiment, the multi-axis gimbal mounting apparatus utilizes a single piece main structure having a pair of live hinges and a locking feature that enhances two kinds of stability. First, the adjustable elements of the mount remain in the intended position when the locking mechanism is actuated with minimal cross-talk between the locking features and the adjustment features. Second, the adjustable elements of the mount remain in the intended position when the mount or the system in which it resides is exposed to extreme environmental perturbations of vibration, temperature, shock, and acceleration. This mount is suitable for use in military laser systems, cryogenic systems, and other industrial optical instruments subjected to harsh environments such as aircraft, ship, and battlefield deployed devices. Furthermore, the mount is compact, easy to adjust, has high resolution and flexibility for optical component mountings, and is easily manufactured.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 USC 119(e) to U.S. Provisional Patent Application No. 60/313,303 entitled “Adjustable Mount For Optical Components”, filed on Aug. 17, 2001. 
    
    
     FIELD OF INVENTION 
     This invention relates to a device for mechanically adjusting an optical element, and more specifically to a device for adjusting the tilt angle of a lens or mirror and locking the position in a manner that is stable over temperature, time and environmental stresses. 
     BACKGROUND 
     An optical mount is a device that points a laser beam by controlling the orientation of an optic. In a laser system, a laser beam strikes an optic and is directed to a further point on the optical pathway by the interaction between the beam and the optic. The optical mount can be used to redirect the laser beam to another point by repositioning the optic. 
     There is a requirement in laser systems for very high thermal and mechanical stability in order to maintain beam quality, output power, beam divergence and mechanical boresight. Lasers are used in precision applications, such as surveying and military targeting, and in demanding environments, such as the environments in which military laser systems typically operate, have such very high stability requirements. 
     Ideally, enhanced stability laser systems would be designed and built with no adjustable components. With everything immovably fixed, alignment and boresight stability would depend solely on the quality of the basic design. There would be less tendency for misalignment in the field. Unfortunately, this option would lead to lasers with relatively broad tolerances and relatively poor performance. Over the years, the laser system industry has developed adjustment systems for lasers and the optical components with which they operate that result in very good laser alignment and stability—albeit at the cost of additional system complexity, increased manufacturing time for alignment of the laser system, and increased labor costs. For laser systems having high stability requirements, such as military laser systems, the additional complexity, time and alignment labor costs are significantly higher. 
     The use of adjustable mounting apparatus for supporting optical components in a laser system such as optical fibers, mirrors, beam splitters, lenses, gratings, and the like, is known. For example, it is frequently necessary to position a first optical element, such as a mirror, optical fiber, or waveguide relative to a second optical element, such as another mirror, optical fiber, waveguide, or beam expander microscope objective lens. Frequently, the relative positioning of such optical components must be very precise, often requiring accuracies on the order of wavelength dimensions. Even smaller allowable tolerances are anticipated in the future. 
     One approach to the design of precision laser system alignment mounts has been based on kinematic mounting, where three directional constraints determine the alignment. Typically, this might be accomplished with two plates, one mounted on the other at three points, the first point being a ball in socket in each of the plates, the second point being a ball in v-grooves in each plate aligned radially with the sockets, and the third point being a screw threaded through one plate and resting on the surface of the second plate on a radial line from the sockets. The plates can be held together with springs attached to their outer edges. This mechanism has a hinge point formed by the two balls. When the screw is adjusted, one plate will tilt with respect to the other and, if one plate is fixed, the edge of the second plate will be translated perpendicular to the radial line from the hinge to the adjustment screw. The difficulty with this semi-kinematic mounting mechanism is that, as additional adjustments are needed along other axes, additional alignment assemblies must be stacked, thereby increasing the size and complexity of the laser system. 
     Typical alignment fixtures use a pair of screws to set the alignment in one direction. One screw is used to push the alignment fixture while the other is used to pull the alignment fixture (opposing screws). When the correct alignment of the laser system has been achieved, both screws are “tightened” to prevent any additional movement of the alignment fixture when the system is exposed to shock and vibration environments. Tightening the adjustment screws, however, will change the system alignment just performed unless it is exactly balanced, and detracts from the ability to make very fine alignment adjustments. Stability of such a locking system is also questionable because the stress induced in the mechanism by the screws is along the direction of adjustment. When the stress changes due to changed environmental conditions, the adjustments change as well. Achieving the exact adjustment balance is very tedious and time consuming, resulting in increased cost and time for manufacturing the laser system. 
     An alternative approach to locking a laser system&#39;s alignment has been to use a single screw pushing against a stiff spring. To lock the alignment fixture after the laser system has been aligned, a nut on the single screw is tightened against the fixture. This is a variant of the two screw approach described in the paragraph above. Both of these locking schemes suffer the same problem of potentially changing the just-performed alignment setting when the locking nut tension is increased, again causing additional time and effort to be spent aligning the laser system, along with the added attendant cost. Both schemes also suffer from the same stability problem because of their reliance on the stress conditions of the interface between the adjustment screw and the mount along the direction of travel. 
     A variety of optical elements can be selected for use as a laser beam relay, depending upon it purpose and application. Laser system design involves a continuing struggle to balance laser performance requirements against the various operational and environmental stability requirements in which the system will operate, and to balance the ease of manufacture and alignment of the laser system against its requirements for long and short term stability in the environment where the delivered laser system will be used. The task of optically aligning the output of a laser beam is alleviated to some extent by the systems disclosed in the prior art. 
     In addition, U.S. Pat. No. 4,869,583 discloses a laser relay mounting assembly which receives and conducts a laser beam wherein the laser relay mounting assembly adjusts the laser output coincident with a desired axis which further describes a locking screw. U.S. Pat. No. 6,198,580 describes a gimbaled optical mount using a bearing element as a pivot point. There is an optical mount with a locking fastener disclosed in U.S. Pat. No. 6,016,230. 
     However, the state of the art implementations have yet to satisfy the commercial applications for an optical mounting and there is considerable room for improvement. Thus, there is a need for improved apparatus for easy alignment of optical components that provides low cross talk and enhanced locking strength. In particular, there needs to be an improved locking mechanism that does not impart forces in the angular direction. There is also a need for improved apparatus that permits fine alignment of optical components and a means for quickly locking the adjusted position of the optical element. Also, there is a need for improved apparatus that will permit aligned optical components to retain their alignment under very adverse and demanding operational and environmental conditions, such as the environments in which military laser systems operate. The locking mechanism should be strong to overcome adverse environmental conditions. 
     SUMMARY OF THE INVENTION 
     The invention is devised in the light of the problems of the prior art described herein. Accordingly it is a general object of the present invention to provide a novel and useful apparatus and technique that can solve the problems described herein. The foregoing needs are satisfied by the apparatus disclosed herein for easy mounting and alignment of optical components in such a manner that permits aligned optical components to retain their alignment under very adverse and demanding operational and environmental conditions. In addition, the mounting and alignment apparatus herein disclosed permits much finer alignment of optical components and permits faster alignment adjustment of the optical components. 
     In one embodiment the present invention comprises three plates coupled by live hinges that provide a two axis gimbal adjustable mount, wherein the locking mechanism sandwiches the moveable plates with a contact force perpendicular to the adjustment axes. The configuration of the present invention allows low cross talk and an environmentally stable clamp. 
     The mounting described herein can be used to hold optical elements that need to be angularly adjusted, such as optical fibers, mirrors, beam splitters, lenses, and gratings. In one embodiment the adjustable optical element mounting is fabricated from a solid block of material and has two live hinges formed therein by narrow cuts through most of the block of material. The axes of the two live hinges lie on radial lines that typically perpendicular (orthogonal) to each other; and the axes of the two live hinges also typically lie perpendicular (orthogonal) to the optical axis of the optical element that is fastened in the optical component mounting. The two live hinges are also oriented so that the motion of each hinge axis is uncoupled or independent from the motion of the other hinge axis. 
     The locking feature of this optical component mounting system clamps the adjustable elements of the mount orthogonal to the direction of their motion. The locking screw for each axis does not touch the adjustable element. Instead, the locking screw passes through a clearance hole in the adjustable element allowing the locking flexures to “sandwich” the adjustable element. When the locking screw is not tight, the adjustable element slides between the locking elements that form the bread of the sandwich. In this way a locking mechanism is formed that does not create cross talk to the adjustable element. This facilitates speed and ease of alignment, as well as a rigid final assembly that lends itself to dimensional stability in rugged environments, such as those typically experienced in military applications. 
     In order to use a single screw for adjustment in each axis, a spring action is provided by each live hinge of the mount. The flexures can be machined with the adjustable plates biased closed, or an external temporary spring similar to a clothespin or large paperclip can be added. In addition, the flexures for the adjustable elements can be machined as separate pieces and then laser welded, screwed and glued, or otherwise fastened to the bases of the adjustable elements to connect the adjustable elements and thereby lower the cost of manufacture. 
     The design of this optical component mounting system is also configured to provide a fixed outer frame that is very rigid, for use in attaching the mounting to a laser system chassis. Adjustment screws for aligning the optical element fastened in the component mounting are located in the rigid outer frame for alignment stability. 
     By using live hinges created by machining slots in the material from which the optical component mounting is made, and locating them on two orthogonal lines radiating from the optical axis, the angular adjustments of the optical component in the mounting are made independent of each other. Thus, the process of aligning the optical component in the mounting is simplified. As shown in FIG. 2, the reference to the X axis and Y axis refers to the coordinate system depicted and more particularly to the angular adjustments along the X axis and the Y axis, more particularly, a θ X  and θ Y  adjustment. For convenience, the reference to the X axis and the Y axis herein relate to the angular θ X  and θ Y  adjustment 
     An object of the invention is a mounting apparatus for mounting an optical element such that the optical axis of the optical element is substantially aligned with corresponding elements in an optical system. The apparatus comprises a mounting body with a first section and a second section separated by a gap and coupled by a live hinge, wherein the first section and the second section have a hinged end at the live hinge and a free end opposing the hinged end, and wherein the first section has an optical receptacle for securing the optical element. There is an adjusting means for changing the gap between the first section and the second section at the free end, thereby adjusting an angular alignment in a first direction. A spring means is coupled to the first section and the second section, thereby providing resistance to increasing the gap. Finally, there is a locking means coupled to the first section and the second section securing the angular adjustment with a contact force substantially perpendicular to the first direction. 
     An object includes the mounting apparatus, wherein the locking means is a pair of plates secured proximate the free end, and wherein the plates extend across the gap and are secured to the first section and the second section. Additionally, the adjusting means is a screw threaded through the first section and contacting the second section. 
     Another object includes the live hinge being a remaining portion of the mounting body and the gap is a slot between the first section and the second section. Alternatively, wherein the live hinge is a portion of flexural material secured at the hinged end between the first section and the second section 
     It should be understood that the mounting apparatus accommodates an optical element which is selected from the group comprising: a lens, a mirror, a single optical fiber, an optical fiber bundle, a grating and a prism. 
     Yet a further object includes the spring means being selected from the group comprising: an external spring mounted across the gap at the free end, a clamp structure clamped across the gap, and an inward bias force introduced by a width of the gap being less at the free end and larger at the hinged end. 
     An object of the invention is a two axis gimbal mounting structure for alignment of an optical element, comprising a housing having a base plate, a middle plate and a front plate. The base plate and middle plate are separated by a first slot and coupled by a first flexible hinge at a first hinge end, and the middle plate and the front plate are separated by a second slot and coupled by a second flexible hinge at a second hinged end. The optical element mount to the front plate. There is a first means for angularly adjusting a first axis of the optical element by changing a gap dimension of the first slot at an adjusting end opposing the first hinge end. There is also a second means for angularly adjusting a second axis of the optical element by changing a gap dimension of the second slot at an adjusting end opposing the second hinge end. In addition, there is a first locking mechanism sandwiching the base plate and the middle plate using a force perpendicular to the first axis, and a second locking mechanism sandwiching the middle plate and the front middle plate using a force perpendicular to the second axis. The two axis gimbal mounting structure uses the first adjusting means to align the first axis of the optical element and the second adjusting means is used to align the second axis of the optical element. In a preferred embodiment, the first axis and the second axis are approximately perpendicular. An additional aspect of the two axis gimbal mounting structure is the inward spring bias of the first slot and the second slot to maintain an opposing resistance to changing the gap dimension. 
     A further object of the two axis gimbal mounting structure is a removeable alignment mechanism that is secured across the adjusting end used by the first and second means for angularly adjusting the respective first and second axis. 
     An additional object of the first means for angularly adjusting the first axis is an elongated member threadably engaging the middle plate and contacting the base plate thereby altering the gap dimension of the first slot. Also, the second means for angularly adjusting the second axis is an elongated member threadably engaging the front plate and contacting the middle plate thereby altering the gap dimension of the second slot. 
     An object of the invention is an apparatus for mounting an optical element with a corresponding optical axes aligned with an optical axes of other elements in an optical system, the apparatus comprising a unitary housing having a base section, a middle section and a front section, each section substantially parallel and coupled to each other by two small sections. The first small section forming a first live hinge between the base section and the middle section having a first free end opposing the live hinge. There is a second live hinge between the middle section and the front section with a second free end opposing the second live hinge. Each section is substantially separated from each other by a respective first and second gap, wherein the first and second gap is formed from narrow slots extending substantially through the housing leaving the respective small sections. The first live hinge allows adjustment along a first axis and the second live hinge allows adjustment along a second axis. In a preferred embodiment the first and second axis are substantially orthogonal. There is a first adjustment member threadably interconnecting the middle section and contacting the base section thereby altering the first gap and adjusting along the first axis. There is also a second adjustment member threadably interconnecting the front section and contacting the middle section thereby altering the second gap and adjusting along the second axis. The device includes a first pair of locking plates oriented on each side end of the base section and the middle section proximate the first free end. The first pair of locking plates is used for bridging the first gap and locking the base section to the middle section with a force substantially orthogonal to the first axis. A second pair of locking plates is oriented on each side end of the middle section and the front section proximate the second free end. The second pair of locking plates is used for bridging the second gap and locking the middle section to the front section with a force substantially orthogonal to the second axis. Finally, there is an optical receptacle on the front section for securing the optical element. 
     Another object includes where the first and second pair of locking plates have a central flexure section. The central flexure section of the locking plates allows the plates to have some flexibility in the direction of the clamping force. The flexure has no impact on the structural integrity once the plates are locked into place. 
     An additional object is the first and second pair of locking plates using a locking bolt extending from the first and second pair of locking plates through a hole in the middle and front sections respectively, with a corresponding nut on the respective opposing first and second pair of locking plates. Included as a variation is where the hole is oversized that allows a securing bolt to cleanly pass through the plates without contact. 
     And a further object is the apparatus for mounting, wherein the first adjustment member and the second adjustment member are removed from contact with the respective base section and the middle section after alignment. 
     In addition, further comprising a threaded insert engaging the adjustment member, wherein the insert is a dissimilar material form the adjustment member. 
     Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein we have shown and described only a preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by us on carrying out our invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
     FIG. 1 a  shows a single axis adjustable optical mount with a live hinge 
     FIG. 1 b  shows a live hinge with a built in spring bias that eliminates the need for a separate spring 
     FIG. 2 shows a right front-quartering view of a two axis optical component mount without locking flexure clamps or optional optical component holder 
     FIG. 3 shows a left front-quartering view of a two axis optical component mount without locking flexure clamps or optional optical component holder 
     FIG. 4 shows a right front-quartering view of the optical component mount of a two axis optical component mount with locking plates and optical receptacle 
     FIG. 5 shows a reverse view of an element holder used to retain optical elements in the component mount 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 a  shows one embodiment that is applied to a device for adjusting the optical axial position of a group of focusing lenses. As shown in FIG. 1 a  a live hinge  1  is formed of a single piece of metal  75  comprising two side pieces  2  and  3  joined at the bottom and containing a narrow slot  8 . Side pieces  2  and  3  are joined at the bottom by a substantially thin bridge of metal  75  having a thickness d2 to allow the side pieces  2  and  3  to flex with respect to each other to provide a living hinge spring function. In the live hinges  11  and  12  shown in FIGS. 2,  3 , and  4 , the dimension d2 will be less than approximately 0.010 inches if mounting  10  is made of Aluminum, will be less than approximately 0.005 inches if mounting  10  is made of steel, and will be between these two dimensions if mounting  10  is made of Titanium. The area of the hinge with dimension d2 can be manufactured separately and fastened to the bottom of side pieces  2  and  3  in a first instance, wherein other materials with differing physical properties can be used. 
     In the embodiment of FIG. 1 a , side piece  2  is thicker than side piece  3 , and is used to attach the living hinge  1  to a frame or other base by fastening means that are not shown in this Figure. There are also coaxial holes  4   a  and  4   b  cut respectively through side pieces  2  and  3 . A lens  5  is mounted in hole  4   b  for illustrative purposes, but other optical elements could similarly be mounted therein. For example, in a very small version of the live hinge, an optical fiber or bundle of fibers could be mounted in hole  4   b . A mirror could be installed in hole  4   b , in which case the corresponding hole  4   a  in side piece  2  would not be necessary. There is also a threaded hole  9  through the upper portion of side piece  3  in which is threaded an adjustment screw  6 . It should be obvious to those in the art that it is only necessary that the screw  6  have a threaded section that interacts with the threaded hole  9  and the portion interacting with side piece  2  can have a flatted end or covering. 
     In their relaxed state, the free ends of side pieces  2  and  3  are spaced a distance d1 apart as shown in FIG. 1 a . As adjustment screw  6  is turned into the threaded hole  9  through the upper portion of side piece  3 , the screw end initially contacts the inside of side piece  2 . As adjustment screw  6  is screwed in further, it pushes against side piece  2 , creating a force F 1  on side piece  3  that forces side piece  3  away from side piece  2 . To permit this movement of side piece  3 , the metal at the bottom of slot  8  flexes, forming the live hinge used in implementing the adjustable mount. A locking nut  7  or similar device aids in keeping the screw from thread slippage. 
     As shown in FIG. 1 b , live hinge  1  is spring loaded toward side piece  3  by one of the methods mentioned herein (biasing, external spring, or internal spring), the flexing at the bottom of slot  8  creates a spring force equal and opposite to force F 1 . In the described embodiment of biasing, this spring force attempts to return side piece  3  to its original position at distance d1 from side piece  2 . The slot  8  may be cut as shown in FIG. 1 b , so that the width d4 of the slot near the base is greater than the width d3 near the top of the slot  8  to produce the spring biasing. This non-parallel slot-width spacing introduces a required spring bias. As the dimension d3 is widened by turning the adjustment screw  6  inward, the spring force F 1  created by outward deflection of the live hinge will try to return the sides  2 ,  3  inward to their original orientation with the live hinge in its relaxed state. Thus, there will be a spring pressure throughout the live hinge&#39;s range of adjustment, which eliminates die need for a separate spring to perform the same function. 
     The use of Wired or Conventional Electric Discharge Machining (EDM) permits the slots to be made non-parallel, as shown in FIG. 1 b  in almost any configuration that achieves low stress condition necessary for functional and stable live hinges. While Conventional and Wired EDM are described herein, other high speed machining is permissible as well as injection molding using various composites. 
     The slots of live hinges  11  and  12  in FIGS. 2 and 3 may be cut as shown in FIG. 1 b , so that the width d4 of the slot near the base is greater than the width d3 near the top of the slot to produce the spring biasing. This non-parallel slot-width spacing introduces a spring bias, and as the dimension d3 is widened during adjustment of mount  10  by turning the adjustment screw inward, the spring force created by outward deflection of the live hinge will try to return the sides inward to their original orientation with the live hinge in its relaxed state. 
     Alternatively, an external spring element could be utilized with posts (not shown) affixed on opposing sides across slots of live hinges  11 ,  12  and a bias spring (not shown) coupled to the posts. The spring and posts could be temporary during the adjustment stage or permanent. A large clothespin type unit could provide the temporary spring bias and be removed once alignment is completed. The prior art also teaches of various means to provide an outward spring bias providing a resistance to decreasing the gap between the slots such as an internal spring and an outward biasing of the plates. 
     Mounted with relation to hole  4   b  in FIG. 1 a  is a component of the optical/laser system in which the live hinge is used, such as lens  5 , that has an optical axis V 1 . As screw  6  is turned inward, side piece  3  is forced away from side piece  2 . This movement of side piece  3  causes the optical axis of lens  5  to shift from V 1  to V 2 , as shown, creating an angular change of angle θ. 
     This illustrates the action of the live hinge used to adjust the optical axis V 1  of optical element  5  up or down, or one degree of freedom. According to the present invention, incorporating a second live hinge with its hinge axis oriented approximately transversely to the axis of the first live, the optical axis of optical element  5  can also be adjusted in an additional degree of freedom. Thus the optical adjustment can be adjusted in two directions, such as up/down and right/left to align the optical element. As discussed, other optical elements such as, but not limited to, mirrors, beamsplitters, fiber optic devices, prisms, and fiber optic cable can similarly be held for alignment. 
     One preferred embodiment of optical component mounting  10  is described herein with reference to FIG.  2  through FIG.  4 . FIG. 2 shows one view of the basic optical component mounting  10 . Mounting  10  is preferably machined from a solid block of material and has two narrow slots forming live hinges  11  and  12  cur through most of the block thickness to create the live hinges  11  and  12 . While all Figures show the width of the open slot creating live hinges  11  and  12  being uniform, when the slots of hinges  11  and  12  are being cut by machine processes, and the width of the slot can be cut narrower at the open end of the slot, and wider at the closed end of the slot and with varied widths. In this manner there is a spring force present caused by forcing the ends apart as the open end is forced apart by an adjusting screw, as detailed herein. 
     FIGS. 2 and 3 show the spacing between the front portion or front plate  90  and the middle portion or middle plate  85  of mount  10 , set by live hinge  12 , and the spacing between the middle portion  85  and the rear portion or base plate  80  of mount  10 , set by live hinge  11 , as parallel, but as indicated herein, the spacing may be other than parallel. The orientation of the hinges  11 ,  12  are designed in order to provide the alignment required for a given application. In certain applications a single live hinge might suffice wherein only a single degree of freedom is required for alignment, In the preferred embodiment, the hinges  11 ,  12  are orthogonal in the X/Y direction, providing alignment in the X and Y direction. Other orientations are within the scope of the invention to provide stable alignment mechanisms for angles other than orthogonal. 
     The preferred material of mounting  10  is metal for extreme stability over environment and time. Other resilient materials, such as plastic or composites, may also be used with injection molding in certain applications and requirements. The various machining and molding technologies allow for a very small mounting  10  with very narrow slots of live hinges  11  and  12 . In either case, a mounting  10  as small as 0.25 inches square can be used to hold one end of a fiber optic cable or bundle of fibers, or a very small optic element of any kind. Thus, one application of this adjustable mount uses mounting  10  for adjusting the optical axis of the optic with respect to the optical axis of other optical components mounted on an optical bench. The locations and orientations of the two transverse narrow slots of live hinges  11  and  12  are better understood by comparing FIGS. 2 and 3. In the embodiment shown, slots of live hinges  11  and  12  can be made as small as only a few thousandths of an inch wide, resulting in the live hinges used for adjustment purposes as generally described with reference to FIG. 1 a.    
     It can be seen in FIGS. 2 and 3 that slots creating the two live hinges  11 ,  12  are both parallel to each other. It can also be seen in FIGS. 2 and 3 that the live hinge flex points at the bottom of slots of live hinges  11  and  12  are perpendicular with respect to each other in this embodiment. The bottom of the slot of live hinge  12  can be seen in FIGS. 2 and 3, and the bottom of the slot of live hinge  11  can only be seen in FIG.  3 . The deflection of each live hinge  11 ,  12  takes place on its thinner front side, when the top of the slot of live hinge  12  is widened through the action of this live hinge, there is a tilting of the optical axis V in the negative Y direction. As the top of the slot of live hinge  12  is narrowed through the action of this live hinge, V similarly tilted upward in the positive Y direction. Likewise, as the top of the slot of live hinge  11  is widened through the action of this live hinge, V is tilted toward the right along the plane of the X axis in the positive X direction. As the top of the slot of live hinge  11  is decreased by the action of this live hinge, V is moved toward the left in the negative X direction. Accordingly, when the two live hinges  11 ,  12  are implemented as shown, there is an X and Y angular adjustment of an optical element mounted in bole  13  of mounting  10 . 
     By orienting live hinges  11  and  12  as shown in FIGS. 2 and 3, a change in adjustment of the width of the slot of live hinge  11  will not affect the adjustment of the existing slot width of live hinge  12 , and visa versa. Without this isolation, the cross effect makes adjustment difficult. This effect is known as cross talk, and it occurs when the placements of adjustment hinge points is such that the resulting X and Y motions are not independent of each other. The present design has negligible cross talk. 
     Hole  13  passes through mounting  10  permitting various optical elements to be coupled therein. For example, an element holder  24  for mounting an optical component, such as a mirror  51 , is shown in FIGS. 4 and 5 attached to mounting  10  and in alignment with hole  13 . The axis of hole  13  is represented in FIGS. 2 and 3 by V, aligned as necessary relative to a beamline of an optical bench or other laser system on which mounting  10  is affixed. In this description the front of mounting  10  is looking into hole  13 . The X and Y axes of mounting  10 , used herein as references in describing mounting  10 , are also shown in FIGS. 2 and 3. 
     As shown in FIGS. 2 and 3, there are additional holes located in or through mounting  10  ( 14 ,  15 ,  18 ,  19 ,  21 ,  22 ,  25 ,  26 ,  27 ,  28 ,  33 ,  34 , and  35 ) are used in attaching mounting  10  to attaching the locking plates  16 ,  17 ,  20  and  23 , for accommodating live hinge locking screws  38  and  39 , and in attaching an optical holder  24  to mounting  10 , as shown in FIGS. 4 and 5. The holes  29  and  30  are used for accommodating adjustment screws  31  and  32  shown in FIG.  4 . 
     Referring to FIGS. 2,  3 , and  4 , holes  14  and  15  in FIG. 2 are used to attach a top side locking plate  16  to mounting  10 . Opposing holes on the bottom of mounting  10 , not seen in FIGS. 2 and 3, are used to attach bottom side locking plate  17  to mounting  10 . Holes  18  and  19  in FIG. 2 are used to attach left side locking plate  20  to mounting  10  with screws  42  and  43 . Holes  21  and  22  in FIG. 3 are used to attach right side locking plate  23  to mounting  10  with screws (not shown). 
     In addition, holes  25 ,  26  and  27  in FIG. 2, and hole  28  in FIG. 3, are used in attaching element holder  24  in FIG. 5 to mounting  10  with screws  42 ,  43 ,  44  and  45  (not seen), as shown in FIG.  4 . Element holder  24  holds optical elements, such as lens  5  in FIG. 1 a , or a mirror, prism, reflector or the end of a fiber optic cable. 
     For the purposes of describing this preferred embodiment, mirror  51  is mounted in element holder  24  as shown in FIGS. 4 and 5. In FIGS. 2 and 3 there is a hole  29  that is used for attaching adjustment screw  31 , shown in FIG. 4, that is used to adjust live hinge  11  to tilt the optical mirror  51  along the plane of the X axis. Similarly, in FIGS. 2 and 3 there is a hole  30  that is used for attaching adjustment screw  32 , shown in FIG. 4, that is used to adjust live hinge  12  to change the angle of the mirror  51  along the Y axis. As previously described with reference to the general description of the live hinge shown in FIG. 1 a , X and Y adjustments are accomplished using adjustment screws  31  and  32 . 
     The preferred embodiment of this adjustable mount uses a completely different approach to locking the alignment settings than the prior art. The alignment settings are made using adjustment screws  31  and  32 , as shown in FIG. 4, to adjust live hinges  11  and  12 , respectively. Once the alignment process is completed, the system is locked according to the description herein with negligible cross talk from the locking mechanism making the adjustment. In a preferred method of alignment, the adjustment screws  31 ,  32  are backed off from the contact with the respective plates. The locking is so effective that insignificant plate movement is experienced when the screws are backed off. There are significant benefits to the long term stability of a mount accomplished by backing off the adjustment screws and removing a contact pressure point from the adjusted plate. This is especially important where the materials for the threaded insert and the screw are of different materials to prevent galling and therefore have different thermal properties. 
     The design of mounting  10  is configured such that three major portions, a rear portion  80 , a middle portion  85 , and a front portion  90 . The rear portion  80 , in which holes  14  and  15  are located, is to the rear of the slot of live hinge  11 . This rear portion  80  is used to attach mounting  10  to a frame, chassis, or optical bench. The middle portion  85  includes the holes  18 ,  19 ,  21 ,  22 ,  29  and  33 . The third portion is the front portion  90  in which holes  13 ,  25 ,  26 ,  27 ,  28 ,  30 , and  34  are located. These three portions  80 ,  85 ,  90  are connected at the flex joint of live hinges  11  and  12  as can be seen in FIGS. 2 and 3. 
     Top side locking plate  16  is attached to the rear portion  80  of mounting  10  by fastening screws  36  and  37  into holes  14  and  15 , as shown in FIGS. 2 and 4. Bottom side locking plate  17  is attached to the lower side of the rear portion  80  in similar fashion by two screws (not shown). Hole  33  in FIG. 2 passes through the middle portion  85  and is ovally elongated as a slot in the preferred embodiment to facilitate the adjustment of live hinge  11 . A locking screw  38  extends through a hole in top side locking plate  16 , through elongated hole  33 , and into a nut  41  (indicated, but not shown) that is attached to bottom side locking plate  17 . 
     In FIG. 4, the live hinge  11  adjustment screw  31  extends through hole  29 , and touches the rear portion  80  of mounting  10 . In operation, when it is desired to adjust live hinge  11 , locking screw  38  is loosened. Adjustment screw  31  is turned clockwise or counter clockwise to adjust the X direction angle of the optical axis of mirror  51 . The mirror  51  is mounted in  24  attached to the front portion of mounting  10  by screws  42 ,  43 ,  44 , and another screw  45  (not shown) in FIG. 4 that extend into boles  25 ,  26 ,  27  and  28  in FIGS. 2 and 3. After the X axis adjustment is completed, locking screw  38  is tightened to clamp the middle portion  85  of mounting  10  between top side locking plate  16  and bottom locking plate  17 . In this manner the X axis optical adjustment is maintained and is not changed when the adjustment locking takes place. 
     In FIG. 4, left side locking plate  20  is attached to the middle portion  85  of mounting  10  by screws  46  and  47  that screw into holes  18  and  19  (see FIG.  2 ). Right side locking plate  23  is also attached to the middle portion  85  of mounting  10  by screws (not shown) that screw into holes  21  and  22  shown in FIG.  3 . It should also be noted that hole  34  in FIG. 2 is also elongated (oval) also called a slot in the preferred embodiment through the front portion  90  of mounting  10  to facilitate adjustment of live hinge  12 . A locking screw  39  extends through a hole in left side locking plate  20 , through elongated hole  34  through the front portion  90  of mounting  10 , and into a nut  40  (not shown) attached to right side locking plate  23 . In FIG. 4, there is also a live hinge  12  adjustment screw  32  that extends through hole  30 , seen in FIGS. 2 and 3, and touches the rear portion  80  of mounting  10 . 
     When it is the desired to adjust live hinge  12 , locking screw  39  is loosened. Adjustment screw  32  is then turned clockwise or counter clockwise to adjust the Y angular direction of the optical axis of mirror  51  that is mounted in holder  24 . After the Y axis adjustment is completed, locking screw  39  is tightened to clamp the front portion  90  of mounting  10  between left side locking plate  20  and right side locking plate  23 . In this matter the Y axis adjustment is maintained and is not changed when the adjustment locking takes place. 
     Ideally both locking screws  38  and  39  would be loose when adjusting the spring biased live hinges  11 ,  12  with sufficient force to make the adjustment with the adjustment screws  31 ,  32 . Once aligned, the locking plates  16 ,  17  and  20 ,  23  sandwich the respective alignment axes as the corresponding locking screw  38 ,  39  is tightened. 
     It is desirable to provide for substantially frictionless motion of the live hinges in the unclamped (unlocked) condition. Therefore, a shim (not shown) may be used on the side locking plates  16 ,  17 ,  20  and  23  to out approximately 0.0005 inch to permit unimpeded motion in the unclamped (unlocked) condition. Alternately, the flexure of the locking plates can be machined with this clearance by design. 
     The locking capability does not change the adjustment of mounting  10 , wherein the side locking plates  16 ,  17 ,  20  and  23  are placed so that the movable parts of mounting  10  (the front portion  90  and middle portion  85  of mounting  10 ) can freely move prior to tightening the locking screws  38  and  39 . In one embodiment, in order to insure this free movement, very thin spacers of low friction material, such as plastic, can be placed between the side locking plates and the movable parts of mounting  10  (the front portion  90  and middle portion  85  of mounting  10  previously described). 
     When locking screw  38  or  39  is tightened, the force applied is orthogonal to the X-Y plane (whichever plane in which live hinge movement for adjustment is allowed) which results in no stress applied thereon, and therefore there is no unwanted movement in the alignment plane. In this way, the alignment is unaffected by the clamping force. Stated another way, if locking screws  38  and  39  are tightened, for example, to four foot-pounds to lock the live hinges  11 ,  12  and temperature or other environmental changes cause the screws to change dimension such that their torque changes up or down to perhaps two foot-pounds or six foot-pounds, the optical adjustment is not affected by the change. 
     In FIG. 4 elements  52  and  53  are internally threaded tubular elements with flattened annular head portions. The flattened annular portions are shown in FIG. 4, and the tubular portions of elements  52  and  53  extend into holes  29  and  30  (FIGS.  2  and  3 ), respectively, where they are not seen. The flattened annular portions of elements  52  and  53  lie under the head of their associated adjusting screws  31  and  32 , and their tubular portions extend and are preferably bonded into the hole  29  or  30  with an adhesive. That is, the tubular portion of washer  52  extends into hole  29 , and the tubular portion of washer  53  extends into hole  30 . Adjustment screws  31  and  32  turn into the threaded portions of their associated tubular elements  52  and  53  to provide the adjustment capability of living hinges  11  and  12 . The ends of adjustment screws  31  and  32  may be rounded hemispherical and polished to reduce friction, and ride against the inner surface of the far side of the living hinge that they bridge. For example, rounded end of adjustment screw  31  rides against the rear portion of mount  10 , and the rounded end of adjustment screw  32  rides against the middle portion of mount  10 . To prevent galling dissimilar metals for the adjustment screws  31 ,  32  and the threaded portions of the inserts  52 ,  53  would be preferred. 
     Adjustment screws  31  and  32  have a uniform, fine thread along their length in the preferred embodiment of the invention but, alternatively, these adjustment screws can each have two different pitch threads thereon. For example, the portion of each screw  31  and  32  nearest the heads can have a 32 pitch, while the lower end of the screws nearest the tips can have a 40 pitch, which provides a more sensitive adjustment of living hinges  11  and  12 . Tighter pitches of 80 or 100 are also known in the art. 
     The adjustable mounting herein described provides an adjustment and locking mechanism that insures long-term retention of mirror  51  alignment in high shock and vibration environments, and does this without affecting the alignment when the locking mechanism is applied. 
     Manufacturing efficiency and enhanced quality of the adjustable mounting can be achieved by using wire EDM that allows the stacking of side locking plates for manufacturing up to nine inches thick, so that many side locking plates can be machined at one time. EDM also produces a substantially smooth surface finish on mounting  10 , which is important for reducing the occurrence of stress concentrations at tool marks, which can occur when these features are made with conventional machine tools. 
     The use of orthogonal side locking plates  16 ,  17 ,  20  and  23  to lock mirror  51 , once it has been adjusted, in a way that does not disturb the adjustment, provides stability in high mechanical and thermal shock environments, including cryogenic environments. This results in significant labor savings during the alignment of optic systems. The benefits are not limited to mirrors. Any optical component requiring fine mechanical adjustment and requiring that the final adjustment be secured will benefit from the use of this adjustable mounting. 
     In the preferred embodiments, side locking plates  16 ,  17 ,  20  and  23  have a thinned-down portion  54 ,  55 ,  56  and  57 . The thinned down portions  54 ,  55 ,  56  and  57  may be produced with Wire EDM machining to create the live hinge in each of the side locking plates. This has the effect of allowing side locking plates  16 ,  17 ,  20  and  23  to flex along the axis of the live hinge so that they will clamp the live hinges  11  and  12  without causing stresses, and yet will be non-compliant in the direction of adjustment so that they will provide a stable clamp. 
     FIG. 5 shows a view of the back or reverse side of element holder  24  that is first described above with reference to FIG.  4 . To help orient FIG. 5 with reference to FIG. 4, mounting screws  42  through  45  are shown. As previously described, element holder  24  holds optical elements such mirror  51  in a cup  49  as shown in this Figure. 
     Stable mounting of mirror  51  can be accomplished by spring loading, as shown in FIG. 5, because mirror  51  does not have precise features to use for mounting purposes. The optically flat surface of mirror  51  is held firm by a wave washer  48  or other spring. Wave washer  48  has the advantage that its applied force will not change over temperature. The force required is determined by the shock environment the assembly will be subjected to. Typically, some large fraction of a pound is enough force. A side spring  50  made from strip steel presses mirror  51  sideways into two mounting blocks (not seen) on the inside walls of element mount  24  to make a semi-kinematic mount. Cup  49  in which mirror  51  is mounted does not have critically close tolerances, because the precision tolerance is on the mounting surface, and is determined by the required stability of mirror  51 . The greatest stability is achieved by optically machining or polishing the mounting surfaces. 
     Another feature of the embodiment of this adjustable mount is that the material from which optical component mounting  10  is machined can be chosen for its coefficient of thermal expansion (CTE). This allows, for example, a material with a CTE that matches that of the mirror or other optical element to be adjusted, or that matches the base to which component mounting will be mounted. This match of CTE reduces stresses in mounted optical components and increases thermal stability of the optical system. 
     The various holes  65 ,  70  in FIG. 4 illustrate an alternate embodiment, wherein the holes are use to attach a separate adjustment mechanism (not shown) as a replacement for the adjustment screws  31 ,  32 . In this alternative embodiment a separate adjustment tool would be screwed into the holes  65 ,  70  and could employ a differential micrometer or similar adjustment device to set the tilt angle before clamping the locking screws  38 ,  39 . Once the alignment is completed, the alignment tool could be removed as the clamping aspects of the present invention would secure the alignment. 
     One embodiment the present invention is used in conjunction with optical fibers, and the alignment of a single fiber or a bundle of fibers are secured by the present optical mount. It is well known in the industry that a bundle of fibers can be aligned over an array of photonic detectors and/or emitters. In lieu of the mirror  51 , the element holder  24  would be configured to retain the optical fibers. 
     Numerous characteristics and advantages have been set forth in the foregoing description, together with details of structures and functions of the present invention, and some of the novel features thereof are pointed out in appended claims. The disclosure, however, is illustrative only, and changes may be made in arrangement and details, within the principle of the invention, to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. For example, the description of screws for the various securing members can be replaced by other members that are known in the art. The objects and advantages of the invention may be further realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. Accordingly, the drawing and description are to be regarded as illustrative in nature, and not as restrictive.