Multi-rebound beam steering

Abstract

The invention relates to multiple rebound beam steering. In some implementations, a beam steering system includes a beam steering element configured to steer a beam having a beam waist, and an optical system configured to return the beam to the beam steering element to provide multiple bounces of the beam on the beam steering element. From inputting the beam to the beam steering element to outputting the beam from the beam steering element, the beam waist of the beam may be maintained.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to U.S. Provisional Patent Application No. 63 / 580,884, entitled “MULTI-BOUNCE BEAM STEERING,” filed on September 6, 2023. The disclosure of the prior application is considered a part of and incorporated by reference into this patent application. Technical Field

[0003] The present disclosure generally relates to beam steering and multi-bounce beam steering. Background Art

[0004] In optical systems, beam steering can be achieved by using mirrors. Beam steering methods can include phased array optics and / or micro-electromechanical systems (MEMS) using micro-mirrors. Summary of the invention

[0005] In some implementations, a beam steering system includes a beam steering element configured to steer a beam having a beam waist, wherein the beam steering element is oriented at an oblique angle relative to the beam. The beam steering system may include an optical system including a first reflector facing the beam steering element and a second reflector facing the first reflector. The optical system may be configured to return the beam to the beam steering element to provide multiple bounces of the beam on the beam steering element. The beam waist of the beam may be maintained from inputting the beam to the beam steering element to outputting the beam from the beam steering element.

[0006] In some implementations, an optical system includes a first reflector configured to face a beam steering element and a second reflector facing the first reflector, the beam steering element being configured to steer a beam having a beam waist. The optical system can be configured to return the beam to the beam steering element to provide multiple bounces of the beam on the beam steering element. The optical system can be configured to image the beam waist of the beam on the beam steering element.

[0007] In some implementations, a beam steering system includes a beam steering element and an optical system, wherein the beam steering element is configured to steer a beam having a beam waist, and the optical system is configured to return the beam to the beam steering element to provide multiple bounces of the beam on the beam steering element. The beam waist of the beam can be maintained from inputting the beam to the beam steering element to outputting the beam from the beam steering element. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a diagram of an example beam steering system;

[0009] Figure 2 is a diagram of an example operation of a beam steering system;

[0010] Figure 3 is a diagram of an example beam steering system; and

[0011] FIG. 4A to FIG. 4B is a diagram of an example of imaging a beam steering element onto itself. DETAILED DESCRIPTION

[0012] The following detailed description of example implementations refers to the accompanying drawings.The same reference numbers in different drawings may identify the same or similar elements.

[0013] Beam steering is useful in applications including three-dimensional (3D) sensing, LiDAR, and / or switching in wavelength selective switch (WSS) devices. Technologies for steering and / or redirecting light can use MEMS mirrors, liquid crystal on silicon (LCoS) devices, and / or optical phased arrays, among others. However, in general, beam steering technologies such as MEMS or LCoS devices have limited steering angles. For example, in MEMS-based beam steering, increasing the MEMS mirror area reduces the steering angle range. As another example, in LCoS-based beam steering, the limited phase range results in insertion loss (IL) losses for very high steering angles. Technologies for increasing the steering angle can use a telescope amplifier (e.g., a dual-lens afocal telescope system) to amplify the beam angle. However, using a telescope amplifier can also change the beam waist, which can negatively impact the performance of applications such as 3D sensing, LiDAR, and the like.

[0014] Some implementations described herein can achieve beam steering with increased steering angles. In some implementations, a beam steering system that produces an increased steering angle can include a beam steering element (e.g., a MEMS mirror) and an optical system. The optical system can be configured to return the light beam to the beam steering element to provide multiple bounces of the light beam on the beam steering element. By directing the light beam to bounce multiple times on the beam steering element, the light beam is steered multiple times by the beam steering element. Therefore, each additional bounce of the light beam on the beam steering element increases the output angle of the light beam.

[0015] In addition, the optical system can be configured to return the light beam to the beam steering element so that the waist of the light beam is incident on the beam steering element. Therefore, the waist of the light beam can be maintained from the input of the light beam to the output of the light beam. In this way, the beam steering system increases the beam steering angle while maintaining the waist of the light beam. Therefore, the beam steering system can be used to improve performance in applications such as 3D sensing, LiDAR, wavelength selective switches, etc.

[0016] Figure 1is a diagram of an example beam steering system 100. The beam steering system 100 may be or may be included in a 3D sensing system, a lidar system, a WSS device, etc. The beam steering system 100 may include a light source 102, a beam steering element 104, and an optical system 106. In some implementations, the beam steering system 100 may include a package, housing, enclosure, etc. that houses the light source 102, the beam steering element 104, and / or the optical system 106.

[0017] The light source 102 may include a device configured to emit a light beam (such as a laser beam) (e.g., the light source 102 may include a laser source). The light beam has a beam waist. For example, the light beam may be a Gaussian beam. The light source 102 may include a vertical cavity surface emitting laser (VCSEL), an edge emitting laser, etc. In some implementations, the light source 102 may be coupled to one or more optical fibers (not shown). For example, the light source 102 may be remote from the beam steering system 100 and coupled to one or more input optical fibers (e.g., input ports) of the beam steering system 100.

[0018] The beam steering element 104 may include a tiltable mirror, a MEMS mirror, an LCoS device (e.g., an LCoS panel), an optical phased array, a metamaterial structure, or another device having the ability to steer a beam. The beam steering element 104 may be configured to reflect the beam. For example, the beam steering element 104 may be configured to reflect the beam. Each interaction (e.g., steering, reflection, etc.) of the beam with the beam steering element 104 may be referred to as a "bounce" of the beam. The beam steering element 104 may be oriented at an oblique angle relative to the beam (e.g., relative to the propagation direction of the beam).

[0019] The beam steering system 100 can be configured to input a beam from a light source 102 to a beam steering element 104 (e.g., shine the beam onto the beam steering element 104). In some implementations, the beam is input to the beam steering element 104 such that a waist of the beam is located at (e.g., imaged at) the beam steering element 104. For example, the waist of the beam can be focused on the beam steering element 104 (e.g., using a lens, etc.). Inputting the beam to the beam steering element 104 results in an initial bounce of the beam on the beam steering element 104, which bounces the beam to the optical system 106.

[0020] The optical system 106 can be configured to return the light beam to the beam steering element 104 (e.g., after the light beam initially bounces from the beam steering element 104). For example, the beam steering element 104 can steer (e.g., reflect) the light beam to the optical system 106 (e.g., in the initial bounce on the beam steering element 104), and the optical system 106 can return the light beam to the beam steering element 104 (e.g., to facilitate at least one additional bounce on the beam steering element 104). Thus, the optical system 106 can be configured to return the light beam to the beam steering element 104 to provide multiple bounces of the light beam on the beam steering element 104 (e.g., an initial bounce on the beam steering element 104 when the light beam is input to the beam steering element 104, and at least one additional bounce on the beam steering element 104 when the light beam is returned to the beam steering element 104 by the optical system 106). For example, the optical system 106 can be configured to provide 2 bounces, 3 bounces, 4 bounces, 6 bounces, etc. of the light beam on the beam steering element 104. In some implementations, the optical system 106 can be configured to return the light beam to the beam steering element 104 such that the waist of the light beam is on the beam steering element 104 (eg, the optical system 106 can be configured to image the waist of the light beam on the beam steering element 104).

[0021] The optical system 106 may include one or more mirrors and / or one or more lenses configured to return the light beam to the beam steering element 104. In some implementations, the optical system 106 may include at least a first mirror 108 and a second mirror 110. The first mirror 108 may be a fixed back mirror of the optical system 106, and the second mirror 110 may be a fixed mirror of the optical system 106. The first mirror 108 (e.g., a reflective surface of the first mirror 108) may face the beam steering element 104 so that the light beam is redirected from the beam steering element 104 to the first mirror 108 one or more times. The second mirror 110 (e.g., a reflective surface of the second reflective mirror 110) may face the first mirror 108. For example, the first mirror 108 may have a reflective surface opposite to the reflective surfaces of the beam steering element 104 and the second mirror 110. A reflector "facing" an element (e.g., beam steering element 104 or another reflector) can mean that the reflector can reflect light onto that element without any additional reflectors (e.g., the element is in front of the reflective surface of the reflector rather than behind the reflective surface of the reflector).

[0022] The second reflector 110 can be aligned (e.g., in-plane) with the beam steering element 104 relative to the first reflector 108. For example, the second reflector 110 and the beam steering element 104 can be located at the same lateral distance from the first reflector 108 (e.g., the distance measured from the center of the second reflector 110 and the beam steering element 104), as shown. The first reflector 108 can be larger than the second reflector 110 and the beam steering element 104.

[0023] In some implementations, such as Figure 1 As shown, the optical system 106 can have a transmissive configuration. For example, the optical system 106 can include a lens 112. The lens 112 can be located between the first reflector 108 and the beam steering element 104 and the second reflector 110. That is, the first reflector 108 can be positioned to a first side of the lens 112, and the beam steering element 104 and the second reflector 110 can be positioned to a second side of the lens 112. For example, the light beam passes through the lens 112 when traveling between the first reflector 108 and the beam steering element 104, and the light beam passes through the lens 112 when traveling between the first reflector 108 and the second reflector 110.

[0024] The first distance between the lens 112 and the first reflector 108 can be approximately equal to (e.g., within ±1%) the second distance between the lens 112 and the beam steering element 104 and the second reflector 110 (e.g., the beam steering element 104, the first reflector 108, and the second reflector 110 can each be approximately the same distance from the lens 112). In some implementations, the focal length of the lens 112 can be configured to focus the beam waist of the light beam on the beam steering element 104, the first reflector 108, and / or the second reflector 110. For example, the focal length of the lens 112 can be approximately equal to (e.g., within ±1%) the first distance and the second distance. For example, the focal length of the lens 112 can be approximately equal to the Rayleigh range of the light beam (e.g., a Gaussian beam). The transmission configuration of the optical system 106 can include one or more additional lenses and / or one or more additional reflectors compared to those described herein, and / or one or more reflectors described herein can be omitted to achieve a desired number of bounces of the light beam on the beam steering element 104. In some implementations, one or more mirrors of the transmissive configuration of the optical system 106 can be flat mirrors, curved mirrors, fixed mirrors, and / or tiltable mirrors. As an alternative to the transmissive configuration, the optical system 106 can have a total reflection configuration that omits lenses, such as in combination with Figure 3 described.

[0025] Furthermore, the optical system 106 may have a different configuration than described herein, so long as the optical system 106 returns the light beam to the beam steering element 104 one or more times to provide multiple bounces of the light beam on the beam steering element 104 .

[0026] The beam steering system 100 can be configured to output a light beam from the beam steering element 104. For example, the beam steering system 100 can output the light beam to the surrounding environment of the beam steering system 100, or one or more output optical fibers (e.g., output ports) of the beam steering system 100, etc. Due to the multiple bounces of the light beam on the beam steering element 104, the light beam is output from the beam steering element 104 at an output angle (e.g., relative to the beam steering element 104).

[0027] In some implementations, the output angle (e.g., caused by multiple bounces of the light beam on the beam steering element 104) is approximately an integer multiple (e.g., ±0.1 of an integer) of the tilt angle of the beam steering element 104. In some implementations, the output angle (e.g., caused by multiple bounces of the light beam on the beam steering element 104) is approximately at least twice (e.g., 1.8 times or more) the steering angle of the light beam from the beam steering element 104 caused by a single bounce of the light beam on the beam steering element 104. For example, if the initial bounce on the beam steering element 104 (e.g., when the light beam is input to the beam steering element 104) reflects the light beam at an angle A, the output angle of the light beam caused by multiple bounces of the light beam on the beam steering element 104 will have an angle of at least approximately 2A. In this manner, the multiple bounces increase the output angle of the light beam. In some implementations, the beam waist of the light beam is maintained (e.g., at the same radius) from input to the beam steering element 104 to output from the beam steering element 104 (e.g., the beam waist of the light beam does not increase due to an increase in the output angle).

[0028] In some implementations, the beam steering system 100 may include an array of beam steering elements, and the beam steering element 104 may be included in the array of beam steering elements. The array may be a one-dimensional array (e.g., a single row or single column of beam steering elements) or a two-dimensional array (e.g., multiple rows and / or multiple columns of beam steering elements). The array may be configured such that each beam steering element is independently controllable. In addition, the number of beams input to the array may be equal to (or less than) the number of beam steering elements in the array. In some implementations, the array of beam steering elements may be used for WSS, etc.

[0029] As mentioned above, Figure 1 is provided as an example. Other examples may be related to Figure 1 Different from what is described.

[0030] Figure 2 is a diagram of an example operation of the beam steering system 100 .

[0031] like Figure 2 As shown in the figure 205, the light beam can be input to the beam steering element 104. For example, the light beam can be focused so that the beam waist of the light beam is incident on the beam steering element 104. As shown in the figure 210, the first bounce on the beam steering element 104 can steer the light beam to the first reflector 108 via the lens 112. As shown in the figure 215, the light beam can be reflected from the first reflector 108, and the first reflector 108 and the lens 112 can image the light beam on the second reflector 110. As shown in the figure 220, the light beam can be reflected from the second reflector 110 to the first reflector 108 via the lens 112. As shown in the figure 225, the light beam can be reflected from the first reflector 108 again, and the first reflector 108 and the lens 112 can image the light beam on the beam steering element 104. As shown in the figure 230, the second bounce on the beam steering element 104 can output the light beam. Therefore, after being bounced twice by the beam steering element 104, the light beam is steered twice by the beam steering element 104, thereby increasing the output angle of the light beam. As described herein, additional bounces of the light beam off the beam steering element 104 may be generated to further increase the output angle of the light beam.

[0032] In some implementations, the tilt angle of the beam steering element 104 can be set at a specific value to produce a specific output angle of the light beam. In some implementations, the tilt angle of the beam steering element 104 can be adjusted when the beam steering system 100 is in use (e.g., when the light source 102 is turned on) to change the output angle of the light beam. For example, the tilt angle of the beam steering element 104 can be adjusted in a sweeping pattern to produce a sweep of the light beam. In some implementations, the beam steering system 100 can include a controller (not shown), or can communicate with a controller, which is configured to control the tilt angle of the beam steering element 104.

[0033] As mentioned above, Figure 2 is provided as an example. Other examples may be related to Figure 2 For example, the optical system 106 may have Figure 2 The different configurations shown (e.g., the optical system 106 can have a reflective configuration, as described herein) will result in the operation of the beam steering system 100 being different from Figure 2 Different from what is described.

[0034] Figure 3 is a diagram of an example beam steering system 100. Figure 3, the optical system 106 has a total reflection configuration. In this reflection configuration, the optical system 106 may include a plurality of reflectors (e.g., a plurality of fixed reflectors). For example, the optical system 106 may include a first reflector 108, a second reflector 110, and a third reflector 114 that also faces the first reflector 108. For example, the first reflector 108 may have a reflective surface that is opposite to the reflective surfaces of the beam steering element 104, the second reflector 110, and the third reflector 114. The second reflector 110 and the third reflector 114 may be aligned with the beam steering element 104 (e.g., in a plane) relative to the first reflector 108 in a manner similar to that described above. For example, the second reflector 110, the third reflector 114, and the beam steering element 104 may be positioned at the same lateral distance from the first reflector 108 in a manner similar to that described above. In some implementations, the second reflector 110 and the third reflector 114 may be arranged at an angle relative to each other and / or relative to the beam steering element 104. In some implementations, the second mirror 110 and the third mirror 114 may be plane mirrors. The second mirror 110 and the third mirror 114 may be configured to image the beam waist of the light beam onto the beam steering element 104 and / or the first mirror 108.

[0035] In some implementations, the first reflector 108 can be a curved reflector in the reflective configuration. For example, using a curved reflector instead of the lens 112 of the transmissive configuration, and using an arrangement of the second reflector 110 and the third reflector 114, can enable the reflective configuration to operate in a similar manner to the transmissive configuration, as described herein. In some implementations, the focal length of the first reflector 108 (e.g., the curved reflector) can be configured to focus the beam waist of the light beam on the beam steering element 104, the second reflector 110, and / or the third reflector 114. For example, the focal length of the first reflector 108 (e.g., the curved reflector) can be approximately equal to the distance between the first reflector 108 and the beam steering element 104. The reflective configuration of the optical system 106 can include one or more additional reflectors compared to those described herein, and / or one or more reflectors described herein can be omitted to achieve a desired number of bounces of the light beam on the beam steering element 104. In some implementations, one or more mirrors of the reflective configuration of the optical system 106 can be flat mirrors, curved mirrors, fixed mirrors, and / or tiltable mirrors.

[0036] As mentioned above, Figure 3 is provided as an example. Other examples may be related to Figure 3 Different from what is described.

[0037] FIG. 4A to FIG. 4B are diagrams of examples 400, 450 of imaging a beam steering element (eg, beam steering element 104) onto itself. Figure 4A Example 400 involves imaging a beam steering element onto itself via a 4f system. Figure 4B Example 450 involves imaging a beam steering element onto itself via an 8f system. The multi-bounce beam steering described herein achieves a constant beam waist and improves steering angle sensitivity (eg, angular magnification). FIG. 4A to FIG. 4B A mathematical basis is provided for achieving a constant beam waist and increased steering angle sensitivity.

[0038] The beam waist can be analyzed by wave function according to JW Goodman's wave operator representation (Goodman, JW, Introduction to Fourier Optics, 3rd ed. (2005)) and the following definition:

[0039]

[0040] Equation 1 (quadratic phase / lens)

[0041]

[0042] Equation 2 (scaling)

[0043]

[0044] Equation 3 (Fourier transform)

[0045]

[0046] Equation 4 (free space propagation)

[0047] where U(x) represents the wave function of the field (e.g., the electric field). In the case of a 2f system, this can be written as:

[0048]

[0049] Equation 5

[0050] The standard result is that for the Fourier plane, there is a scaling and Fourier transform 2D relationship between the planes. In the case of a 4f imaging system, it can be found that:

[0051]

[0052] Equation 6

[0053] And the relationship:

[0054]

[0055] Equation 7

[0056]

[0057] Equation 8

[0058] This gives the result that a 4f system images a Gaussian beam with the same beam waist but with the opposite wave to V[-1]. This means that the beam waist is also preserved for 8f, 12f, etc. systems, and the inversion disappears for 8f, 16f, ... 8Nf, etc. systems. The inversion of the beam waist can be problematic. For example, due to the inversion, the beam at the beam steering element cannot be easily imaged back onto itself to achieve twice the beam steering angle. As described in the ray optics analysis below, the inversion problem can be solved using an 8f-like imaging system. The beam waist characteristics described in this article can be extended even for off-axis beams by staying reasonably within the paraxial approximation.

[0059] Ray optics analysis can focus on tracing the chief rays of a Gaussian beam as it propagates along the imaging system. Figure 4A Example 400 in FIG. 4 shows a 4f system (which is Figure 4B is expanded in to describe 8f, 12f, etc. imaging systems). In particular, Figure 4A The paraxial transmission model of an imaging system with a steering element, as described in this article, is shown. As shown, the angle of the steered beam ends up unchanged due to the inversion effect of the 4f imaging system.

[0060] The following standard ray matrix representation is adapted from BEA Saleh and MC Teich (Saleh, BEA, Teich, MC, Fundamentals of Photonics. Part 1: Optics, 3rd ed. (2019)):

[0061]

[0062] Equation 9 (Light Matrix)

[0063]

[0064] Equation 10 (ray matrix)

[0065] Therefore, for the 2f system and the 4f system, the ray matrix is ​​as follows:

[0066]

[0067] Equation 11 (2f ray matrix)

[0068]

[0069] Equation 12 (4f ray matrix)

[0070] The beam position and angle at each stage of the optical system will now be described. The beam has an initial position y0 and an angle θ0:

[0071]

[0072] After hitting the beam steering element, add the beam steering element angle contribution φ s :

[0073]

[0074] And after the 2f system:

[0075]

[0076] Equation 13

[0077] where the position and angle have been flipped based on the focal length. This affects the design of the optical system, as the position of the beam steering element does not change, and thus the output angle, but the position after 2f does change.

[0078] The chief ray then passes through another 2f system (actually a 4f system), producing:

[0079]

[0080] Equation 14

[0081] Therefore, imaging the steering element surface onto itself (choosing y0=0 allows this) may produce undesirable results because the angle is flipped in direction. In a 4f system, imaging the beam steering element onto itself gives a total angle θ f :

[0082] θ f =-θ0-φ s +φ s =θ0

[0083] Equation 15

[0084] where the last two elements show how the contributions of the beam steering elements cancel each other out, as Figure 4A shown.

[0085] To avoid this, the 8f system can be used. Figure 4B The paraxial transmission imaging design is shown and illustrates how the beam steering element angle is magnified. Figure 4B In example 450, y0=0 and θ0=0 for clarity.

[0086] After 8f system:

[0087]

[0088] Equation 16

[0089] And when the beam steering element is added again:

[0090] θ f =θ0+φ0+φ0=θ0+2φ0

[0091] Equation 17

[0092] The output angle achieves twice the steering from the beam steering element. In an 8Nf system, 8f imaging is performed N times:

[0093] θ f =θ0+Nφ0

[0094] Equation 18

[0095] This illustrates the multiple bounce nature of angular magnification.

[0096] Therefore, reference Figure 1 and Figure 2 , a single lens can be used to 8f self-image the beam steering element 104 to double the beam steering angular range. For example, the first reflector 108 is located at the 2f and 6f points of the imaging system. The 4f image is formed at the second reflector 110 below the beam steering element 104. The 8f plane is returned to the beam steering element 104, where the beam is incident with the appropriate orientation and direction to amplify the effect of the beam steering element 104. Figure 1 and Figure 2 In the example of FIG. 1 , a double bounce is shown. By adjusting the input angle, the initial angle of the beam steering element 104, and / or the lens aperture, a larger beam magnification (eg, more than two bounces) can be achieved.

[0097] As mentioned above, FIG. 4A to FIG. 4B Provided as an example only. Other examples may be related to FIG. 4A to FIG. 4B Different from what is described.

[0098] The above disclosure provides illustration and description, but is not intended to be exhaustive or to limit the implementation to the precise form disclosed. Modifications and variations may be made in accordance with the above disclosure, or may be obtained from the practice of the implementation. In addition, any implementation described herein may be combined, unless the above disclosure explicitly provides reasons why one or more implementations cannot be combined.

[0099] Although specific combinations of features are listed in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various implementations. In fact, many of these features can be combined in ways that are not specifically listed in the claims and / or not disclosed in the specification. Although each dependent claim listed below can directly depend on only one claim, the disclosure of various implementations includes each dependent claim combined with each other claim in the claim set. As used herein, a phrase referring to "at least one" in a list of items refers to any combination of these items, including a single component. For example, "at least one of a, b, or c" is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical items.

[0100] When a component or one or more components (e.g., a reflector or one or more reflectors) is described or claimed (either within a single claim or across multiple claims) as performing multiple operations or being configured to perform multiple operations, the language is intended to broadly cover a variety of architectures and environments. For example, unless otherwise expressly required (e.g., by use of "first component" and "second component" or other language in the claim that distinguishes between components), the language is intended to cover a single component performing or being configured to perform all operations, a group of components collectively performing or being configured to perform all operations, a first component performing or being configured to perform a first operation and a second component performing or being configured to perform a second operation, or any combination of components performing or being configured to perform operations. For example, when a claim is of the form "one or more components are configured to: perform X; perform Y; and perform Z," the claim should be interpreted as "one or more components are configured to perform X; one or more (possibly different) components are configured to perform Y; and one or more (possibly different) components are configured to perform Z."

[0101] Unless explicitly stated, any element, behavior or instruction used in this article should not be interpreted as key or necessary. In addition, as used in this article, the article "one" and "an" are intended to include one or more projects, and can be used interchangeably with "one or more". In addition, as used in this article, the article "the" is intended to include one or more projects quoted in combination with the article "the", and can be used interchangeably with "one or more". In addition, as used in this article, the term "set" is intended to include one or more projects (for example, a combination of related projects, unrelated projects, or related projects and unrelated projects), and can be used interchangeably with "one or more". In the case of only intending to use a project, the phrase "only one" or similar language is used. In addition, as used in this article, the term "has", "have", "having" etc. are intended to be open terms. In addition, unless otherwise explicitly stated, the meaning of the word "based on" is "at least partially based on". In addition, as used in this article, the term "or" is inclusive when used in a series, and can be used interchangeably with "and / or", unless otherwise explicitly stated (for example, if used in combination with "any one" or "only one"). In addition, for ease of description, spatially relative terms (such as "rear", "front", etc.) may be used herein to describe the relationship of one element or feature to another element or feature, as shown in the figures. Spatially relative terms are intended to cover different orientations of devices, equipment, and / or elements in use or operation other than the orientation shown in the figures. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein may also be interpreted accordingly.

Claims

1. A beam steering system, comprising: a beam steering element configured to steer a beam having a beam waist, wherein the beam steering element is oriented at an oblique angle relative to the beam; as well as Optical system, including: a first reflector, the first reflector facing the beam steering element; as well as a second reflector, the second reflector facing the first reflector, wherein the optical system is configured to return the light beam to the beam steering element to provide multiple bounces of the light beam on the beam steering element, and The beam waist of the light beam is maintained from inputting the light beam into the light beam steering element to outputting the light beam from the light beam steering element.

2. The beam steering system of claim 1, wherein the optical system further comprises a lens between the first reflector and the beam steering element and the second reflector.

3. The beam steering system of claim 1, wherein the beam steering element and the second reflector are at the same distance from the first reflector.

4. The beam steering system of claim 1, wherein the optical system further comprises a third reflector facing the first reflector.

5. The beam steering system according to claim 1 further comprises an array of beam steering elements, wherein the array of beam steering elements comprises the beam steering element.

6. The beam steering system of claim 1 , further comprising: A light source is configured to output the light beam.

7. The beam steering system of claim 1, wherein the beam steering element is a micro-electromechanical system (MEMS) mirror, a liquid crystal on silicon (LCoS) device, an optical phased array, or a metamaterial structure.

8. The beam steering system according to claim 1, wherein an output angle of the beam from the beam steering element caused by the multiple bounces of the beam on the beam steering element is approximately an integer multiple of the tilt angle.

9. An optical system comprising: a first reflector, the first reflector being configured to face a beam steering element, the beam steering element being configured to steer a beam having a beam waist; as well as a second reflector, the second reflector facing the first reflector, wherein the optical system is configured to return the light beam to the beam steering element to provide multiple bounces of the light beam on the beam steering element, and Wherein the optical system is configured to image the beam waist of the light beam onto the beam steering element.

10. The optical system of claim 9, wherein the optical system is configured to return the light beam to the beam steering element such that the beam waist of the light beam is located on the beam steering element.

11. The optical system of claim 9, wherein the optical system further comprises a lens between the first reflector and the second reflector.

12. The optical system of claim 11, wherein a first distance between the lens and the first reflector is approximately equal to a second distance between the lens and the second reflector.

13. The optical system of claim 12, wherein a focal length of the lens is approximately equal to the first distance and the second distance.

14. The optical system according to claim 9, further comprising a third reflecting mirror facing the first reflecting mirror.

15. A beam steering system comprising: a beam steering element configured to steer a beam having a beam waist; as well as an optical system configured to return the light beam to the beam steering element to provide multiple bounces of the light beam on the beam steering element, The beam waist of the light beam is maintained from inputting the light beam into the light beam steering element to outputting the light beam from the light beam steering element.

16. The beam steering system of claim 15, wherein the optical system comprises: a first reflector, the first reflector facing the beam steering element; a second reflector, the second reflector facing the first reflector; as well as A lens is between the first reflector and the beam steering element and the second reflector.

17. The beam steering system of claim 15, wherein the optical system comprises: a first reflector, the first reflector facing the beam steering element; a second reflector, the second reflector facing the first reflector; as well as A third reflector, wherein the third reflector faces the first reflector.

18. The beam steering system of claim 15, wherein the beam steering element is a micro-electromechanical system (MEMS) mirror, a liquid crystal on silicon (LCoS) device, an optical phased array, or a metamaterial structure.

19. The beam steering system of claim 15, wherein the optical system is configured to return the beam to the beam steering element such that the beam waist of the beam is located on the beam steering element.

20. A beam steering system according to claim 15, wherein an output angle of the beam from the beam steering element caused by the multiple bounces of the beam on the beam steering element is approximately at least twice a steering angle of the beam from the beam steering element caused by a single bounce of the beam on the beam steering element.

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