Systems and methods for beam direction through a window

A system is provided that includes a light source, a first mirror, a second mirror, and a support structure. The light source provides light energy along an optical path extending along an optical axis. The first mirror receives and re-directs the light energy from the light source, and pivots about an azimuth axis. The second mirror receives the re-directed light energy from the first mirror and to re-direct the light energy toward a target through a window. The support structure has a first end and a second end. The first end is mounted at a support rotation point, with the support structure rotating about the support rotation point as the first mirror pivots about the azimuth axis. The second mirror is mounted to the second end of the support structure.

FIELD OF EMBODIMENTS OF THE DISCLOSURE

Embodiments of the present disclosure generally relate to systems and methods for directing a light beam, for example directing a light beam through an exit window of an aircraft.

BACKGROUND OF THE DISCLOSURE

Optical beam directors may be used to provide relatively wide angle steering of optical beams, such as high and low power lasers, and/or optical sensors. Conventionally, installation of such systems on an air vehicle may involve a relatively large turret exterior to the outer mold line (OML) of the aircraft that increases drag and/or induces effects on the optical system such as jitter and wavefront error.

SUMMARY OF THE DISCLOSURE

Accordingly, improved beam direction, for example, without requiring the use of turrets, is provided in various embodiments disclosed herein.

Certain embodiments of the present disclosure provide a system that includes a light source, a first mirror, a second mirror, and a support structure. The light source provides light energy along an optical path extending along an optical axis. The first mirror is disposed along the optical path, and receives and re-directs the light energy from the light source. The first mirror to pivot about an azimuth axis. The second mirror receives the re-directed light energy from the first mirror and to re-direct the light energy toward a target through a window. The support structure has a first end and a second end. The first end is mounted at a support rotation point, and the support structure rotates about the support rotation point as the first mirror pivots about the azimuth axis. The support structure rotates about the azimuth axis or an axis parallel to the azimuth axis. The second mirror is mounted to the second end of the support structure.

Certain embodiments of the present disclosure provide a system. The system includes an enclosure, a light source, a first mirror, a second mirror, and a support structure. The enclosure has a boundary defining an interior and an exterior, and includes an exit window disposed along the boundary. The light source is disposed within the interior of the enclosure, and provides light energy along an optical path extending along an optical axis. The first mirror is disposed within the interior of the enclosure along the optical path, and receives and re-directs the light energy from the light source. The first mirror pivots about an azimuth axis. The second mirror is disposed within the interior of the enclosure, and receives the re-directed light energy from the first mirror and to re-direct the light energy toward a target through the exit window. The support structure is disposed within the interior of the enclosure. The support structure has a first end and a second end. The first end is mounted at a support rotation point. The support structure rotates about the support rotation point as the first mirror pivots about the azimuth axis. The support structure rotates about the azimuth axis or an axis parallel to the azimuth axis. The second mirror is mounted to the second end of the support structure.

Certain embodiments of the present disclosure provide a method. The method includes providing light energy from a light source along an optical path extending along an optical axis. The method also includes receiving the light energy with a first mirror disposed along the optical path, the first mirror pivots about an azimuth axis. Further, the method includes directing the light energy with the first mirror toward a second mirror. Also, the method includes receiving the redirected light energy from the first mirror with a second mirror. The method also includes directing the light energy with the second mirror toward a target through a window. The support structure has a first end and a second end, with the first end mounted at a support rotation point. The support structure rotates about the support rotation point as the first mirror pivots about the azimuth axis, with the support structure rotating about the azimuth axis or an axis parallel to the azimuth axis. The second mirror is mounted to the second end of the support structure.

DETAILED DESCRIPTION OF THE DISCLOSURE

Embodiments of the present disclosure provide systems and methods for directing a light beam out of a window toward a target. Various embodiments provide a heliostat beam director (that pivots along two axes, e.g., a roll and elevation) with an added mirror to direct the output beam from a first mirror toward an exit window via the added mirror. For example, in some embodiments, the added mirror is disposed along a roll axis rotation stage, travels at a predetermined ratio relative to a first mirror tip stage to compensate for beam walk, and also rotates about its own axis to keep the beam lined up with an exit aperture (e.g., exit window). Such an arrangement may have an annular field of regard (FOR) with a minimum tilt defined by a laser beam size and distance from the exit aperture, and a maximum tilt limited by the size of the exit aperture due to lengthening of an off-axis beam.

Various embodiments provide a beam that is steered toward the center of an exit window, reducing the required window size relative to conventional steering flat beam directors. In various embodiments, a telescope (if utilized) may be disposed off-gimbal, reducing the complexity of the on-gimbal system and requiring only a fixed-telescope arrangement. In various embodiments, the entire optical system (including light source, mirrors, and support structure) is disposed within a desired envelope (e.g., within the OML of an aircraft, and/or within a predefined enclosure volume). Various embodiments provide a high energy laser beam director, a directed countermeasure beam director, a scanning optical sensor, and/or a beam director for an optical communications system.

FIG. 1provides a schematic top view of a system100. Generally speaking, the system100provides light energy to a target. For example, the system100may strike a target with a laser. As another example, the system100may use light directed toward a target for sensing purposes. As another example, the system100may direct a light beam for optical communications. As seen inFIG. 1, in the illustrated embodiment, the system100includes a light source110, a first mirror120, a second mirror130, and a support structure140, all of which are disposed within an enclosure101.

The depicted enclosure101includes a boundary102that defines an interior103and an exterior104. The boundary102is depicted schematically as a line, but in practice may define a 3-dimensional volume within the interior103. The boundary102may define or conform to the OML of an aircraft. For example, the boundary102in various embodiments may be the fuselage or body of an aircraft, the interior103may be the interior volume of the aircraft, and the exterior104may be an external atmosphere. In the illustrated embodiment, the enclosure101includes an exit window105disposed along the boundary102. The exit window105in various embodiments is a conformal window that generally adheres to or maintains the profile, shape, or envelope defined by the boundary102(e.g., to conform or fit within an OML of an aircraft). In contrast to the depicted exit window105or a conformal window, a turret extends beyond a profile, shape, or envelope of a structure associated with the turret, and disrupts the profile, shape, or envelope of such a structure. The exit window105in various embodiments provides a passageway for light energy (e.g., a laser) to pass from the interior103toward a target located in the exterior104. In the illustrated embodiment, all of the components of the system100, including the light source110, first mirror120, second mirror130, and support structure140are disposed within the interior103, removing the need for a turret and providing a smooth, generally continuous boundary surface, for example for improved aerodynamics.

The depicted light source110provides light energy along an optical path111, with the initial path of the light energy out of the light source110defining an optical axis112. In the illustrated embodiment, the optical axis passes through the exit window105. The light source110in various embodiments includes a laser source, and provides a beam. In the illustrated embodiment, the light energy is a beam having a beam width113.

As seen inFIG. 1, the first mirror120is disposed along the optical axis112and optical path111. The first mirror120receives and re-directs the light energy from the light source110. Light emitted from the light source110travels along the optical path111and along the optical axis112toward the first mirror120. As seen inFIG. 1, the first mirror120is oriented at an oblique angle to the optical axis112(e.g., a reflective surface of the first mirror120is neither normal to nor parallel to the optical axis112). Accordingly, the light energy is re-directed by the first mirror120so that the optical path111leaving the first mirror is no longer aligned with the optical axis112. The first mirror120pivots about an azimuth axis122. InFIG. 1, the azimuth axis122is perpendicular to the optical axis112and passes through the optical axis112. For example, the first mirror120may be mounted to a shaft extending along the azimuth axis122, with the shaft actuated by a motor or other device to pivot about the azimuth axis122. By pivoting the first mirror120about the azimuth axis122, the angle at which the optical path111and light energy are re-directed may be adjusted to aim the light energy.

As seen inFIG. 1, the depicted second mirror130is not disposed along the optical axis112. The second mirror130of the illustrated embodiment receives the re-directed light energy from the first mirror120, and to re-direct the light energy through a window (e.g., exit window105) toward a target outside of the enclosure101. Generally, the second mirror130has a reflective surface that receives the re-directly light energy from the first mirror120, with the light reflected off of the reflective surface of the second mirror130redirected toward the exit window105and target. Accordingly, light may leave the light source110along the optical axis112, reflect off the first mirror120toward the second mirror130, and then reflect off the second mirror130toward the exit window105and/or a target outside of the enclosure101. The optical path111thus aligns with or coincides with the optical axis112between the light source110and the first mirror120, but does not align with or coincide with the optical axis112between the first mirror120and the second mirror130or between the second mirror130and the exit window105.

Generally speaking, the depicted support structure140supports the second mirror130and to maintain the second mirror130in a position at which the second mirror130receives the re-directed light energy from the first mirror120to again re-direct the light energy (and optical path111) toward the exit window105and target. As seen inFIG. 1, the support structure140of the illustrated embodiment has a first end142and a second end144, with the support structure extending along a length with the second end144opposite the first end142. It may be noted that the support structure140is depicted schematically as a single straight rod inFIG. 1, but may be shaped otherwise in various embodiments. For example, the support structure140may include a tube or other structure that surrounds a periphery or circumference of the first mirror120and/or second mirror130. As another example, the support structure140may include a plurality of rods disposed about a profile defined by the first mirror120and/or the second mirror130, and extending between the first mirror120and the second mirror130.

The first end142of the support structure is mounted at a support rotation point146, and rotates about the support rotation point146as the first mirror120pivots about the azimuth axis122. The support structure140rotates about the azimuth axis122or an axis parallel to the azimuth axis122. For example, in some embodiments, the support rotation point146is located along the azimuth axis122(e.g., the first end142of the support structure140is mounted to the first mirror120along the azimuth axis122), while in other embodiments, the support rotation point146is offset from the azimuth axis (e.g., the first end142is mounted to a separate portion of the interior103) with the support structure140rotating around an axis that is parallel to but offset from the azimuth axis122. As the support structure140is mounted at the support rotation point146proximate the first end142of the support structure, a distance from the support rotation point146to the second end144defines a radius at which the second end144rotates or sweeps about the support rotation point146.

Further, as seen inFIG. 1, the second mirror130is mounted to the second end144of the support structure140. Accordingly, as the second end144of the support structure140rotates about the support rotation point146as the first mirror120pivots about the azimuth axis122, the second mirror130(which is mounted to the second end144) also rotates about the support rotation point146as the first mirror120pivots. In embodiments in which the support rotation point146and azimuth axis122are aligned, the second mirror130rotates about the azimuth axis122as the first mirror120pivots about the azimuth axis. In some embodiments, the second mirror130does not pivot or rotate with respect to the support structure140, while in other embodiments the second mirror130does pivot or rotate with respect to the support structure140(e.g., the second mirror130pivots about an axis passing through the second end144). By rotating the second end144and, accordingly, the second mirror130, about the support rotation point146, the second mirror130may be maintained along the optical path111as the optical path departs from the first mirror120. It may further be noted that the system100(or aspects thereof) may also rotate about a roll axis190to provide for further flexibility in aiming the optical path111out of the exit window105toward a target.

In the illustrated embodiment, the roll axis190extends along the optical axis112. Various aspects of the system100rotate as a unit about the roll axis190, including the first mirror120, the second mirror130, and the support structure140. For example, with reference toFIG. 1, the second mirror130may rotate about the roll axis190toward or away from a viewer out of the plane of the figure.FIG. 11is a schematic side view of the system100as seen from the exterior104looking into and through the exit window105. As seen inFIG. 11, the roll axis190(and optical axis112) extend normal to the plane of the figure, pass through the center of the first mirror120, and are perpendicular to the azimuth axis122. In the illustrated embodiment, the first mirror120, support structure140, and second mirror130rotate as a unit about the roll axis190(e.g., clockwise or counter-clockwise along direction191). As the second mirror130travels in an arc along direction191around the first mirror120, an annular field of regard is defined by light reflecting off of the second mirror130and passing through the exit window105.

In some embodiments, the support structure140is mounted to the first mirror120or otherwise disposed along the azimuth axis122. For example,FIG. 2aillustrates an example embodiment of the system100in which the support rotation point146is disposed along the azimuth axis122.FIG. 2ais a sectional schematic view taken along lines2-2ofFIG. 1. For the example depicted inFIG. 2a, the first end142is mounted to the first mirror120along the azimuth axis122. InFIG. 2a, the support structure140includes a pair of rods210extending along a length of the support structure140(or from the first end142to the second end144), with the rods210disposed along the periphery of a reflective surface220of the first mirror120. The rods210are mounted to the first mirror120via shafts230that extend along the azimuth axis122, with the shafts230fixed to the first mirror120(e.g., either directly or via a frame) such that the shafts230(and support structure140) rotate with the first mirror120as the first mirror120pivots about the azimuth axis122. For the embodiment depicted inFIG. 2a, a first motor128drives a shaft129to pivot the first mirror120(and support structure140) about the azimuth axis122. The shaft129is coupled to the support structure140and extends along the azimuth axis122. It may be noted that the second mirror130may be mounted to the rods210(or other structure of the support structure140) in some embodiments in a manner which allows pivoting of the second mirror130with respect to the support structure140(e.g., mounted to a shaft that is allowed to rotate in a bearing mounted to the support structure140), and in other embodiments in a manner which does not allow pivoting of the second mirror130with respect to the support structure140(e.g., fixedly mounted to a shaft that is in turn fixedly mounted to the support structure140). It may be noted that the first mirror120may be mounted directly or indirectly to a frame or structure within the interior103to maintain the first mirror120in position along the azimuth axis122.

As another example of an embodiment in which the support structure140is mounted to the first mirror120or otherwise disposed along the azimuth axis122,FIG. 2billustrates another example embodiment of the system100in which the support rotation point146is disposed along the azimuth axis122.FIG. 2bis a sectional schematic view taken along lines2-2ofFIG. 1. For the example depicted inFIG. 2b(as well as for the example depicted inFIG. 2A), the first end142is mounted to the first mirror120along the azimuth axis122. InFIG. 2b, the support structure140includes a tubular frame240extending along a length of the support structure140(or from the first end142to the second end144), with the tubular frame disposed along the periphery of a reflective surface220of the first mirror120(such that light is directed from the first mirror120on the interior of the tubular frame240or through the opening of the tubular frame240. The tubular frame240of the support structure140is fixed to the first mirror120such that the tubular frame240rotates with the first mirror120as the first mirror120pivots about the azimuth axis122. For the embodiment depicted inFIG. 2b, a first motor128drives a shaft129to pivot the first mirror120(and support structure140) about the azimuth axis122. The shaft129is coupled to the support structure140and extends along the azimuth axis122. It may be noted that the second mirror130may be mounted to the tubular frame240in some embodiments in a manner which allows pivoting of the second mirror130with respect to the tubular frame240(e.g., mounted to a shaft that is allowed to rotate in a bearing mounted to the tubular frame240), and in other embodiments in a manner which does not allow pivoting of the second mirror130with respect to the tubular frame240(e.g., fixedly mounted to a shaft that is in turn fixedly mounted to the tubular frame240).

Referring again toFIG. 1, as the support structure140of the illustrated embodiments rotates with the first mirror120, the depicted support structure140may be understood as being rotationally constrained with the first mirror120. In various embodiments, the support structure140may be rotationally constrained with the second mirror130, or, in other embodiments, the support structure140may not be rotationally constrained with the second mirror130. Put another way, in some embodiments, the second mirror130is free to rotate with respect to the support structure140, while in other embodiments the second mirror130is not free to rotate with respect to the support structure. Rotation of the second mirror130in various embodiments allows the optical path111to remain fixed (or nearly fixed) at or near a center of the exit window105, for example, as the first mirror120is pivoted and the support structure140and second mirror130rotate responsive to the pivoting of the first mirror120. In other embodiments, the second mirror130may be prevented from pivoting with respect to the second end144of the support structure140, thereby allowing some amount of “walk” of the optical path111with respect to the center of the exit window, but also allowing for reduced weight, expense, and/or size of the system100.

For example,FIG. 3aillustrates a schematic view of an embodiment of the system100in which the second mirror130pivots with respect to the second end144of the support structure140. In the embodiment illustrated inFIG. 3a, the second mirror130is mounted to the second end144of the support structure140along a second mirror axis126, and pivots about the second mirror axis126as the first mirror120pivots about the azimuth axis122. In various embodiments, the pivoting of the second mirror130is controlled so that the second mirror130maintains direction of the light energy (along optical path111) at a predetermined location (e.g., a portion of the exit window105such as the center of the exit window105, and/or a predetermined target). In the embodiment depicted inFIG. 3a, the system100includes two motors—a first motor128(see alsoFIGS. 2aand 2b) and a second motor310. The first motor128is coupled to the first mirror120and pivots the first mirror120(and the support structure140) about the azimuth axis122(e.g., via shaft329. The second motor310is coupled to the second mirror130and is pivots the second mirror130about the second mirror axis126. For example, the second motor310may drive a second shaft330that extends along the second mirror axis126. The amount of rotation that the second motor310actuates the second mirror130may be determined based on the amount of rotation of the first mirror120along with the geometrical relationships between the first mirror120, second mirror130, and desired orientation of optical path111(e.g., through the center of the exit window105). Accordingly, the first motor128and second motor310may be controlled to rotate the first mirror120and the second mirror130, respectively, a desired amount to direct the optical path111toward a target while maintaining the optical path111at an orientation to pass through the center of the exit window105(or at another desired orientation).

As another example,FIG. 3billustrates a schematic view of another embodiment of the system100in which the second mirror130pivots with respect to the second end144of the support structure140. In the embodiment illustrated inFIG. 3b, the second mirror130is mounted to the second end144of the support structure140along a second mirror axis126, and pivots about the second mirror axis126as the first mirror120pivots about the azimuth axis122. The arrangement ofFIG. 3bcontrols the pivoting of the second mirror130so that the second mirror130maintains direction of the light energy (along optical path111) at a predetermined location (e.g., a portion of the exit window105such as the center of the exit window105, and/or a predetermined target). In the embodiment depicted inFIG. 3b, the system100includes a first motor128(see alsoFIGS. 2a, 2b, and 3a) and a geared linkage350. The first motor128is coupled to the first mirror120and is to pivot the first mirror120about the azimuth axis122(e.g., via first shaft329). The geared linkage350is coupled to the first motor128(e.g., via first shaft329or a separate output shaft) and to the second mirror130. The geared linkage350rotates the second mirror130a predetermined desired amount relative to the rotation of the first mirror120. In the illustrated embodiment, the geared linkage350includes a second shaft330that extends along a second mirror axis126, and the geared linkage pivots the second mirror130about the second mirror axis126. The amount of rotation (and accordingly, one or more gear ratios of the geared linkage350) of the second mirror130may be determined based on the geometrical relationships between the first mirror120, second mirror130, and desired orientation of optical path111(e.g., through the center of the exit window105). It may be noted that the geared linkage350in various embodiments need not necessarily include gears, but may include belts or other variable drive mechanisms alternatively or additionally.

Accordingly, for example using arrangements such as those represented byFIGS. 3aand 3b, the second mirror130may pivot with respect to the second end144of the support structure. For example,FIG. 1provides another example of pivoting of the second mirror130with respect to the support structure. In the embodiment depicted inFIG. 1, as the first mirror120pivots about the azimuth axis122, the support structure140(and second mirror130which is mounted to the support structure140) rotate to keep the optical path111from the first mirror centered on the second mirror130. Also, the second mirror130pivots with respect to the second end144of the support structure140(e.g., pivots about a second mirror axis126as discussed in connection withFIGS. 3aand 3b) to keep the optical path111centered on the exit window105.

In other embodiments, the second mirror130may be rotationally fixed with respect to the second end144of the support structure140, for example to reduce cost, weight, and/or complexity of the system100.FIG. 4illustrates an example embodiment of the system100in which the second mirror130does not pivot relative to the second end144of the support structure140. As seen inFIG. 4, the first mirror120has been pivoted to a position at which the optical path111after being re-directed by the second mirror130is no longer centered on the exit window105. It may be noted that at some rotational positions of the first mirror120, the optical path111may be centered on the exit window105, but at other rotational positions, the optical path111may be allowed to walk or vary from the center of the exit window105. The geometrical relationships between the first mirror120and the second mirror130(e.g., the distance at which they are separated, the angular position of the second mirror130with respect to the first mirror120) may be selected to maintain the amount of walk or variance of the optical path111from the center of the exit window105within a tolerable or desired range.

In the embodiments depicted inFIGS. 1 and 4, the first end142of the support structure140is mounted to the first mirror120such that the support rotation point146lies along the azimuth axis122. Accordingly, the support structure140rotates about the same axis that the first mirror120pivots about. In other embodiments, however, the axis of rotation for the support structure140may not coincide with the axis of pivoting of the first mirror120. For example,FIG. 5illustrates an example embodiment of the system100in which the support rotation point146is disposed along the optical axis112but offset from the azimuth axis122. A support structure axis147passes through the support rotation point146and is oriented parallel to the azimuth axis122, with the support structure140rotating about the support structure axis147. For example, the first end142of the support structure140may be rotationally mounted to a structure510located in the interior103, with the support structure140rotates about the support rotation point146passing through the structure510(e.g., via a shaft passing through the structure510extending along the support structure axis147). Generally, the support structure140rotates a predetermined amount relative to a rotation or pivoting of the first mirror120about the azimuth axis122to maintain the optical path111on the second mirror130as the first mirror120pivots. For example, a motor may be mounted to a shaft that has an axis passing through the support rotation point, with the motor controlled to rotate the support structure140at a desired rate relative to rotation of the first mirror120to maintain the optical path111on the second mirror130. (SeeFIG. 3afor an example of a motor pivoting the second mirror130; a similar arrangement may be used to rotate the support structure.) As another example, a shaft passing through the structure510and along an axis parallel to the azimuth axis122may be driven by the first motor128via a geared linkage. (SeeFIG. 3bfor an example of a geared linkage pivoting the second mirror130; a similar arrangement may be used to rotate the support structure.) Locating the support rotation point146off of the azimuth axis122allows an additional degree of freedom in selecting geometry to suit a particular application.

FIG. 6provides another example in which the axis of rotation for the support structure140does not coincide with the axis of pivoting of the first mirror120.FIG. 6illustrates an example embodiment of the system100in which the support rotation point146is disposed offset from both the optical axis112the azimuth axis122. A support structure axis147passes through the support rotation point146and is oriented parallel to the azimuth axis122, with the support structure140rotating about the support structure axis147. For example, the first end142of the support structure140may be rotationally mounted to a structure610located in the interior103, with the support structure140rotating about the support rotation point146passing through the structure610(e.g., via a shaft extending along the support structure axis147). Generally, as with the example discussed in connection withFIG. 5, the support structure140rotates a predetermined amount relative to a rotation or pivoting of the first mirror120about the azimuth axis122to maintain the optical path111on the second mirror130as the first mirror120pivots. Locating the support rotation point146off of the azimuth axis122and off of the optical axis112provides an additional amount of freedom in selecting geometry to suit a particular application. It may be noted that for either of the arrangements represented byFIG. 6 or 7, the second mirror130may pivot with respect to the second end144of the support structure140in some embodiments, and not pivot with respect to the second end144of the support structure140in other embodiments.

It may be noted that in some embodiments, the optical axis112may not pass through the exit window105. For example,FIG. 7illustrates an example of the system100in which the optical axis112does not pass through the exit window105. Instead, the exit window105is offset from the optical axis112. The angle of the second mirror130relative to the first mirror120is selected to direct the optical path111to the exit window105. Location of the exit window105off of the optical axis allows for additional flexibility in defining the range over which the optical path111may be directed. For example, in the example ofFIG. 1, it may not be possible to direct the optical path111toward a target outside of the interior103that is along the optical axis112, or to direct the optical path111directly normal to the boundary102. However, it may be possible with an arrangement such as that represented byFIG. 7to direct the optical path111toward a target outside of the interior103that is parallel to the optical axis112, and/or to direct the optical path111directly normal to the boundary102.

FIG. 8provides a flowchart of a method800for directing or aiming light energy (e.g., a laser), in accordance with various embodiments. The method800, for example, may employ or be performed by structures or aspects of various embodiments (e.g., systems and/or methods and/or process flows) discussed herein. In various embodiments, certain steps may be omitted or added, certain steps may be combined, certain steps may be performed concurrently, certain steps may be split into multiple steps, or certain steps may be performed in a different order.

At802, a first mirror (e.g., first mirror120) of a system (e.g., system100) is pivoted to a desired location (e.g., a predetermined location corresponding to delivering light energy through a window to a desired target). The first mirror in various embodiments is pivoted about an azimuth axis. Generally, the first mirror is located to receive light energy from a light source and to re-direct the light energy toward a second mirror (e.g., second mirror130). In various embodiments, the first mirror and other components of the system are disposed within an interior volume, such as an interior volume of an aircraft.

At804, the second mirror is positioned at a desired location relative to the first mirror to re-direct light energy received from the first mirror through an exit window toward a target. In various embodiments, the second mirror is mounted to a support structure that rotates when the first mirror pivots to maintain the optical path from the first mirror being directed toward the second mirror. In various embodiments, the support structure has a first end and a second end, with the first end mounted to a support rotation point, and with the second mirror mounted to the second end of the support structure. The support structure is rotates about a support rotation point as the first mirror pivots about the azimuth axis. In some embodiments the support structure rotates bout the azimuth axis. In some embodiments, the support structure rotates about an axis that is parallel to the azimuth axis.

In some embodiments, positioning the second mirror includes not only rotating the support structure, but also pivoting the second mirror with respect to the support structure. For example, in the illustrated embodiment, the second mirror is mounted to the second end of the support structure along a second mirror axis, and, at806, the second mirror is pivoted about the second mirror axis as the first mirror pivots. For example, in some embodiments, the first mirror is pivoted about the azimuth axis using a first motor, and the second mirror is pivoted about the second mirror axis using a second motor, with the second motor controlled based on the rotation of the first mirror to maintain the second mirror in a position relative to the first mirror to deliver the optical path to a desired location. As another example, in some embodiments, the first mirror is pivoted about the azimuth axis using a first motor, and the second mirror is pivoted about the second mirror axis via a geared linkage coupling the second mirror to the first motor.

At808, light energy from a light source (e.g., light source110) is provided along an optical path extending along an optical axis. The first mirror is disposed along the optical path. The light source, for example, may be a laser.

At810, the light energy is received with the first mirror. As discussed herein, the first mirror pivots about the azimuth axis. At812, the light energy is directed toward the second mirror with the first mirror. At814, the light energy is received by the second mirror from the first mirror, and, at816, the light energy is directed with the second mirror toward a target through a window (e.g., exit window105). The positioning of the first mirror, and the positioning of the second mirror with respect to the first mirror, determines the direction of the beam. Accordingly, the first mirror and second mirror are controlled to be positioned to provide a desired direction or orientation of the optical path through the exit window so that the target is aligned along the optical path leaving the exit window.

Examples of the present disclosure may be described in the context of aircraft manufacturing and service method1200as shown inFIG. 9and aircraft1202as shown inFIG. 10. During pre-production, method1200may include specification and design (block1204) of aircraft1202and material procurement (block1206). During production, component and subassembly manufacturing (block1208) and system integration (block1210) of aircraft1202may take place. Thereafter, aircraft1202may go through certification and delivery (block1212) to be placed in service (block1214). While in service, aircraft1202may be scheduled for routine maintenance and service (block1216). Routine maintenance and service may include modification, reconfiguration, refurbishment, etc. of one or more systems of aircraft1202. For example, in various embodiments, examples of the present disclosure may be used in conjunction with one or more of blocks1208,1210, or1216.

As shown inFIG. 10, aircraft1202produced by illustrative method1200may include airframe1218with a plurality of high-level systems1220and interior1222. Examples of high-level systems1220include one or more of propulsion system1224, electrical system1226, hydraulic system1228, and environmental system1230. Any number of other systems may be included. Although an aerospace example is shown, the principles disclosed herein may be applied to other industries, such as the automotive industry. Accordingly, in addition to aircraft1202, the principles disclosed herein may apply to other vehicles, e.g., land vehicles, marine vehicles, space vehicles, etc. In various embodiments, examples of the present disclosure may be used in conjunction with one or more of airframe1218or interior1222.

Apparatus(es) and method(s) shown or described herein may be employed during any one or more of the stages of the manufacturing and service method1200. For example, components or subassemblies corresponding to component and subassembly manufacturing1208may be fabricated or manufactured in a manner similar to components or subassemblies produced while aircraft1202is in service. Also, one or more examples of the apparatus(es), method(s), or combination thereof may be utilized during production stages1208and1210, for example, by substantially expediting assembly of or reducing the cost of aircraft1202. Similarly, one or more examples of the apparatus or method realizations, or a combination thereof, may be utilized, for example and without limitation, while aircraft1202is in service, e.g., maintenance and service stage (block1216).