Patent ID: 12203751

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the technology as oriented inFIG.1. However, it is to be understood that the technology may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

The present technology may be described in terms of functional block components and various processing steps. Such functional blocks may be realized by any number of components configured to perform the specified functions and achieve the various results. For example, the present technology may employ various optical devices, materials, and geometries, which may carry out a variety of operations. In addition, the technology described is merely one exemplary application for the disclosed device. Further, the present technology may employ any number of conventional techniques or methods of redirecting, focusing, expanding, polarizing, or manipulating a laser beam or other like beam of light.

Methods and apparatus for an adjustable beam directing optical system according to various aspects of the present technology may operate in conjunction with any type of laser-based measurement system such as a focused laser differential interferometer (FLDI) instrument. Various representative implementations of the present technology may be applied to any type of laser device or optical measurement system. Referring now toFIG.1, in one representative embodiment, a beam directing optical system100may comprise a beam splitter102positioned to receive an incident laser beam116and split it into two beams, a polarizing element104positioned immediately downstream from the beam splitter102, and a pair of beam realignment devices106,108configured to redirect the two beams towards a target114.

The beam splitter102is configured to split an incoming laser beam into two or more beams that can be used to increase the measuring capability of a FLDI or other like optical measurement system. The beam splitter102may comprise any system or transparent optical device for splitting a beam into two or more beams such as a Rochon prism, a Wollaston prism, a calcite beam displacer, and the like.

In one embodiment, the beam splitter102may comprise a Wollaston prism suitably configured to receive a laser beam116on a first side and split the beam into two separate orthogonally polarized beams118,120that exit from an opposing side of the prism. The two orthogonally polarized beams118,120may be split by an equal, but opposite angle about an optical axis122of the FLDI (shown along the z-axis ofFIG.1) that may also coincide with the axis of the incoming incident laser beam116. For example, the Wollaston prism may be configured to split the incoming initial laser beam116into two beams by a splitting angle (θS). A first beam118may be angled from the optical axis122by an angle one-half that of θS. Similarly, a second beam120may be angled from the optical axis122by an angle that is also one-half that of θSbut opposite the optical axis122as the first beam118thereby forming two beams that are symmetric about the optical axis122of the FLDI.

The splitting angle θSmay comprise any suitable angle and may be selected according to any criteria such as the type of optical instrument being used, the environment, available space, or desired sensitivity. For example, the splitting angle (θS) may comprise an angle of between about five degrees and about forty-five degrees.

With reference now toFIGS.1-3, the beam splitter102may be housed within or otherwise connected to a rotation mount304. The rotation mount304may allow the beam splitter102to be rotated about the optical axis122to help set an orientation of the beam splitter102relative to the first beam realignment device106. For example, after the incoming diverging laser beam126has been split into two beams118,120, the beam splitter102may be rotated within the rotation mount304to allow for proper alignment of the two beams118,120with a pair of windows204,206disposed in the first beam realignment device106. Once aligned, the rotation mount304may be configured to lock the beam splitter102in position to keep the beams118,120and windows204,206aligned during use.

The beam splitter102may also be configured to split the incoming laser beam116without disrupting a state or condition of the beam itself. For example, the incoming laser beam116may be passed through an initial polarizing element110such as a ½ wave plate or other similar device or filter. The polarized beam may then pass through a diverging lens112that is used to form an expanding laser beam126. The beam splitter102may allow the expanding laser beam126to continue expanding as it passes through the beam splitter102while maintaining the symmetry of the two separate orthogonally polarized beams118,120about the optical axis122of the FLDI. In an alternative embodiment, and referring now toFIGS.10and11, the initial polarizing element110may be positioned between the diverging lens112and the beam splitter102.

Referring again toFIG.1, a second polarizing element104located immediately downstream of the beam splitter102may be configured to adjust the polarization of the two beams118,120after they exit the beam splitter102and before the enter the first beam realignment device106. For example, in one embodiment, the polarizing element104may comprise a ½ wave plate configured to reorient the polarization state of the two beams such that they are at ±45 degrees relative to a splitting plane (x-z plane as shown inFIG.1) of the beam splitter102.

Referring now toFIGS.2and3, the polarizing element104may be housed within or otherwise connected to a second rotation mount306. The second rotation mount306may allow the polarizing element104to be rotated about the optical axis122to help set an alignment of the polarizing element104relative to the two split beams118,120and the first beam realignment device106. Once aligned, the second rotation mount306may be configured to lock the polarizing element104in position during use. Similarly, the initial polarizing element110may be housed within or otherwise connected to a third rotation mount1002as shown inFIG.10.

Referring now toFIGS.1-4, the first beam realignment device106may be positioned to receive the two beams118,120from the polarizing element104and redirect the beams parallel to the optical axis122. The first beam realignment device106may comprise any system or device capable of redirecting the two beams118,120. In one embodiment, the first beam realignment device106may comprise a housing having a pair of openings configured to hold a pair of optical windows204,206disposed within the housing and positioned such that each window204,206is able to receive one of the two beams118,120. The housing may be formed of a forward portion308and a back portion310coupled together to at least partially enclose the pair of optical windows204,206.

The pair of optical windows204,206may each be configured to receive a beam of light through a first side at a first angle and then redirect the beam such that it exits an opposing second side parallel to the optical axis122. For example, a first window204may be configured to refract the first beam118towards the optical axis122by an angle that is equal to one-half θS. Similarly, the second window206may be configured to refract the second beam120towards the optical axis122by an angle that is also equal to one-half θS.

Referring now toFIGS.1-5, the second beam realignment device108is positioned downstream from the first beam realignment device106and is configured to redirect the two beams118,120towards the optical axis122. The second beam realignment device108may comprise any system or device capable of redirecting the two beams118,120. In one embodiment, the second beam realignment device108may comprise a housing and a second pair of optical windows404,406disposed within the housing and aligned with the first pair of optical windows204,206such that each optical window404,406is able to receive one of the two beams118,120from the first beam realignment device106.

The second pair of optical windows404,406may be configured to receive a beam of light through a first side at a first angle and then redirect the beam towards the optical axis122when it exits an opposing second side. The combined redirection angle of the second pair of optical windows404,406may comprise a crossing angle (θC). The θCmay determine a crossing distance (Δx) where the two beams118,120will each cross the optical axis122at the same crossing location124. For example, the first optical window404may be configured to refract the first beam118towards the optical axis122by an angle that is equal to one-half θC. Similarly, the second optical window406may also be configured to refract the second beam120towards the optical axis122by one-half θC.

The crossing location124may be adjusted or altered by changing the crossing angle of the two beams118,120. For example, by increasing the crossing angle the crossing distance may be reduced bringing the crossing location124closer to the second beam realignment device108. Conversely, by decreasing the crossing angle the crossing distance may be increased moving the crossing location124further away from the second beam realignment device108.

The housing of the second beam realignment device108may be configured to allow the second pair of optical windows404,406to be interchangeable with one or more other optical windows configured to refract the first and second beams118,120by any desired angle. For example, referring now toFIG.5, the second pair of optical windows404,406may be configured to be fixed within a removable optical mount502positioned between a forward portion312and a back portion314coupled together to at least partially enclose the optical mount502. In one embodiment, and referring now toFIGS.7-9, the back portion314may be configured to allow the optical mount502to be slid into and out of a slot702the housing. For example, a rear facing surface of the back portion314may comprise a slot702configured to allow the optical mount502to be removed. The back portion314may further comprise a set of thru holes802configured to receive a set of screws configured to hold the optical mount502in place.

The optical mount502may then be selectively removed by the user and replaced with a second optical mount (not shown) housing another pair of optical windows404,406to adjust the crossing angle of the second pair of optical windows404,406. In alternative embodiments, the optical mount502may be configured with one or more other optical windows selected to redirect the two beams118,120at any desired angle. For example, and with particular reference toFIG.12, the second beam realignment device108may comprise only a single optical window1202that is configured to redirect the second beam120away from the optical axis122by a second splitting angle (θS2). The second beam realignment device108may allow the first beam118to progress unrefracted such that it remains parallel to the optical axis122. In this embodiment, the first and second beams118,120do not cross and may be directed towards two different points.

In a third embodiment, and with reference now toFIG.13, the second beam realignment device108may not comprise any optical windows. In this configuration, the second beam realignment device108may allow the first and second beams118,120to progress unrefracted such that they both remain parallel to the optical axis122. In this embodiment, the first and second beams118,120do not cross and may be directed towards two different points.

Referring now toFIG.14, in a fourth embodiment, the second beam realignment device108may be configured to further split the first and second beams116by a third splitting angle (θS3). The first beam118may be angled from the optical axis122by an angle one-half that of θS3and the second beam120may also be angled from the optical axis122by an angle that is also one-half that of θS3but opposite the optical axis122as the first beam118thereby maintaining the symmetric distance of the first and second beams118,120about the optical axis122of the FLDI. For example, the second beam realignment device108may comprise a first diverging optical window1402that is configured to redirect the first beam118away from the optical axis122by one-half θS3and a second diverging optical window1404that is configured to redirect the second beam120away from the optical axis122by one-half θS3. In this embodiment, the first and second beams118,120do not cross and may be directed towards two different points.

In yet another embodiment, the second beam realignment device108may be configured to cross the first and second beams118,120at an off-axis location. With reference now toFIG.15, the second beam realignment device108may comprise only a single optical window1502that is configured to redirect the second beam120towards the optical axis122by a second crossing angle (θC2). The second beam realignment device108may allow the first beam118to progress unrefracted such that it remains parallel to the optical axis122. In this embodiment, the first and second beams118,120will cross at an off-axis target1504.

The second beam realignment device108may comprise any suitable combination of zero, one, or two optical windows to perform a desired function. The combination may be selected according to a type of measurement instrument that the beam directing optical system100is being used with or according to a desired type of measurement. One of skill in the art will recognize that the specific combinations described above are not exhaustive and represent a small sample of exemplary embodiments.

The optical mount502may comprise a thru hole902and an opening for each optical window404,406. The thru hole902may allow an adjustment screw604to be accessed during use to adjust the distance between the first and second beam realignment devices106,108as detailed below.

Referring again toFIG.5, a pair of o-rings504,506may be used to provide some protection to the optical windows404,406. For example, an o-ring may be fitted around an outer peripheral surface or edge of each optical window404,406to help reduce a likelihood of the optical windows404,406being chipped or cracked or to prevent foreign debris from entering the optical mount502. Any other suitable device may be used to protect the optical windows404,406such as sealants or insulating materials.

The housing of the first beam realignment device106may be similarly constructed with an optical mount for the pair of optical windows204,206that is configured to be positioned within the forward portion308and the back portion310. The housing may also be configured to allow for the replacement of the optical windows204,206.

Referring now toFIGS.1,3,4, and6, the second beam realignment device108may be configured to provide the ability to finely adjust the crossing location124of the two beams118,120when the beam directing optical system100is in use. For example, a desired beam crossing location124may coincide with a target114such as another prism. However, once the beam directing optical system100is positioned within the FLDI instrument the actual crossing location124may not be located exactly at the target114. By moving the second beam realignment device108slightly forward or aft (longitudinally along the optical axis122) in the FLDI instrument, a user may be able to adjust the crossing location124to the desired location.

The second beam realignment device108may be configured in any suitable manner to allow it to be moved along the optical axis122. In one embodiment, an adjustment mechanism302may connect the first and second beam realignment devices106,108together and allow the second beam realignment device108to be moved forward or aft relative to the first beam realignment device106. For example, the adjustment mechanism302may comprise an adjustment screw604and a spring602positioned around the spring to engage a rear facing surface of the first beam realignment device106and a forward facing surface of the second beam realignment device108.

The adjustment screw604may be rotated to adjust a separation distance between the first and second beam realignment devices106,108. By bringing the first and second beam realignment devices106,108closer together the crossing location124may be moved in the direction of the first and second beam realignment devices106,108. Conversely, by increasing the separation distance between the first and second beam realignment devices106,108, the crossing location124may be moved towards the target114.

The spring602engages both of the beam realignment devices106,108and is biased to act against an exterior surface of each component. The spring force acting against the first and second beam realignment devices106,108allows for more precise control of the separation distance between the first and second beam realignment devices106,108when the adjustment screw604is turned.

The beam directing optical system100may further comprise a mounting system configured to be connected to each component and maintain an alignment of each component during use. The mounting system may also be configured to allow the beam directing optical system100to be rotated longitudinally about the optical axis. For example, referring now toFIGS.2-4, a set of alignment rods208may be connected to the beam splitter102, the polarization element104, and the first and second beam realignment devices106,108to maintain the position and alignment of each component. The alignment rods208may comprise any suitable device or structure for providing a rigid connection. The alignment rods208may also comprise any shape or size and may be selected according to a given use or application. For example, the alignment rods208may comprise tubular rods or rectangular bars configured to provide a rigid mounting structure.

In one embodiment, the alignment rods208may comprise a plurality of metallic rods having a length of between about two inches (50 mm) and about eight inches (203 mm) arranged around peripheral edges of the individual devices. For example, the beam directing optical system100may comprise four alignment rods208configured to extend through a set of openings positioned at outer corners of the housings that hold each component. The housings for each component may comprise a generally square shape such that the outer corners of each housing are spaced equidistant from the optical axis122.

An end of each alignment rod208may be attached to a mount202configured to secure the beam directing optical system100into the FLDI instrument during use. The mount202may comprise any device capable of engaging the alignment rods208and fixing them in place. In one embodiment, the mount202may be configured to rotate the entire beam directing optical system100about the optical axis122in unison thereby allowing the user to change the orientation of the beams azimuthally relative to the optical axis.

In operation of a first embodiment as represented byFIGS.1and11, a beam splitter102may be positioned to receive an incoming laser beam116/126and split the beam into two orthogonally-polarized beams118,120equally about an optical axis122of a FLDI instrument. A polarizing element104may be located downstream of the beam splitter102and be configured to reorient a polarization state of the two beams118,120such that they are at ±45 degrees relative to a splitting plane of the beam splitter102.

A first beam realignment device106may be positioned to receive the two beams118,120through a pair of optical windows204,206that are configured to redirect each beam118,120so that it exits the first beam realignment device106parallel to the optical axis122such that both beams118,120are still spaced symmetrically about the optical axis122. The amount each beam118,120is redirected by the respective optical window204,206may be determined according to a splitting angle created by the beam splitter102when it splits the incoming laser beam116/126.

A second beam realignment device108is positioned to receive the two beams118,120exiting the first beam realignment device106and redirect them towards the optical axis122such that the two beams118,120cross each other at the optical axis122at a predetermined crossing location124. The crossing location124is determined according to a crossing angle created when the two beams118,120exit the second beam realignment device108.

The crossing location124of the two beams118,120may be adjusted slightly to allow a user to ensure that the beams118,120properly hit a target114positioned at the intended crossing location124. For example, a longitudinal position of the second beam realignment device108along a length of the beam directing optical system100may be adjusted to provide the ability to change the exact crossing location124.

These and other embodiments for methods of beam directing may incorporate concepts, embodiments, and configurations as described above. The particular implementations shown and described are illustrative of the technology and its best mode and are not intended to otherwise limit the scope of the present technology in any way. Indeed, for the sake of brevity, conventional manufacturing, connection, preparation, and other functional aspects of the system may not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and/or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may be present in a practical system.

The description and figures are to be regarded in an illustrative manner, rather than a restrictive one and all such modifications are intended to be included within the scope of the present technology. Accordingly, the scope of the technology should be determined by the generic embodiments described and their legal equivalents rather than by merely the specific examples described above. For example, the components and/or elements recited in any apparatus embodiment may be assembled or otherwise operationally configured in a variety of permutations to produce substantially the same result as the present technology and are accordingly not limited to the specific configuration recited in the specific examples.

As used herein, the terms “comprises,” “comprising,” or any variation thereof, are intended to reference a non-exclusive inclusion, such that a process, method, article, composition or apparatus that comprises a list of elements does not include only those elements recited, but may also include other elements not expressly listed or inherent to such process, method, article, composition or apparatus. Other combinations and/or modifications of the above-described structures, arrangements, applications, proportions, elements, materials or components used in the practice of the present technology, in addition to those not specifically recited, may be varied or otherwise particularly adapted to specific environments, manufacturing specifications, design parameters or other operating requirements without departing from the general principles of the same.

The present technology has been described above with reference to exemplary embodiments. However, changes and modifications may be made to the exemplary embodiments without departing from the scope of the present technology. These and other changes or modifications are intended to be included within the scope of the present technology, as expressed in the following claims.