Spatially light-switched telescope

Abstract

The utility model provides a kind of telescope of spatial light switching, including collimating mirror, vibrating mirror and beam expander group distributed in turn along light beam path, input light is shot into vibrating mirror after collimating by collimating mirror, vibrating mirror deflection makes light beam deflection different angle, and the reflected light of different angle emission is emitted to detection space by beam expander group. Between vibrating mirror and beam expander group, multiple mirror groups can be further provided to form multi-stage reflection spatial light switching telescope system. The utility model realizes the multi-channel switching of radar by collimating mirror, vibrating mirror, mirror, beam expander, compared with prior art, not only reduce the optical power loss caused by fiber coupling, reduce fiber SBS effect, better control the consistency of each channel detection carrier-to-noise ratio, and the power consumption is lower compared with rotating wedge mirror scheme.

Description

Technical Field

[0001] This utility model relates to the field of wind-measuring lidar, specifically a telescope with spatial light switching. Background Technology

[0002] Wind-measuring lidar uses the laser Doppler frequency shift velocimetry principle to measure the radial wind speed of aerosols. It then calculates the wind speed vector by collecting radial wind speeds from multiple different directions, and finally inverts the three-dimensional wind field. The multi-directional wind speeds are often collected using a telescope system with multi-channel beam switching.

[0003] Wind-measuring lidar is mainly used in wind farm monitoring for wind power generation, aviation, and meteorology. For example, in wind power applications, wind-measuring lidar is typically installed on top of wind turbines to remotely monitor the wind field in the direction the turbine blades face. This allows the turbine blades to adjust their attitude based on real-time wind speed and direction, improving power generation efficiency and reducing blade bending. However, the turbine blades can block the light signal emitted by the lidar during operation, reducing the data efficiency of the wind-measuring lidar. Therefore, this places demands on the number of channels in the multi-channel telescope and the angle between the channels. The more channels and the larger the angle between channels, the more complex the multi-channel beam switching telescope system becomes.

[0004] Existing multi-channel switching telescopes for wind-measuring lidar primarily employ the following two technical approaches: Option 1 employs fiber optic switches and a multi-channel telescope. Multiple channels are output from the fiber optic switches, and then connected to the multi-channel telescope via multiple fiber optic jumpers, thus emitting the laser in different directions within the detection space. Common fiber optic switches used in this option include microelectromechanical systems (MEMS) optical switches and magneto-optical switches. Light propagating within these switches requires multiple fiber couplings, resulting in significant optical power loss and poor consistency in the carrier-to-noise ratio across channels. Furthermore, stimulated Brillouin scattering (SBS) occurs in the fiber, and this effect is proportional to the fiber length. Once the SBS exceeds a certain accumulation threshold, the temporal stability of the emitted radar pulse light deteriorates. In particular, magneto-optical switches utilize the Faraday magneto-optical effect to achieve polarization direction rotation and optical channel selection. However, wind-measuring lidar is often deployed in harsh environments (e.g., deserts, cold regions, and at sea). Changes in ambient temperature cause variations in the Wilder constant of the magneto-optical material, leading to decreased accuracy in the polarization direction rotation of the incident light, increased optical power loss, and abnormal spectral phenomena such as interference noise.

[0005] Option 2 uses a monocular telescope with a rotating wedge mirror to achieve multi-channel switching. The wedge mirror refracts the beam, and a rotary motor rotates the wedge mirror to achieve channel switching or scanning. To prevent the wedge mirror and its mounting components from blocking light, this option requires increasing the diameter of the wedge mirror. The increase depends on the wedge mirror material, the beam angle of the multi-channel beams, and the structural design of the wedge mirror mounting components. The larger the wedge mirror, the greater the load on the motor, and the larger and more power-consuming the motor. For example, the rotary motor and its control circuit used for a 50mm diameter wedge mirror have a power of approximately 9.6W. In addition, the operating environment of wind-measuring lidar is subject to interference such as wind turbine vibration and ground vibration. Furthermore, the center of gravity of the wedge mirror is off-axis relative to the rotating motor. The lifespan of the rotating motor will be reduced if it operates in such an environment for a long time. The operating temperature of wind-measuring lidar is between -40 and 60°C. Under these temperature conditions, the change in the refractive index of the wedge mirror will cause the beam deflection angle to change. For example, the deflection angle of a Si wedge mirror with a deflection angle of 28° at 20°C will change by 0.2° at -40°C or 60°C. Utility Model Content

[0006] To address the problems of existing technologies, this invention provides a telescope for spatial light switching. It achieves multi-channel switching of radar through a collimating mirror, a galvanometer, a reflector, and a beam expander. Compared with existing solutions, it not only reduces optical power loss caused by fiber coupling and reduces the fiber SBS effect, but also better controls the consistency of the carrier-to-noise ratio of each channel. At the same time, it consumes less power than the rotating wedge mirror solution.

[0007] This invention provides a telescope for spatial light switching, comprising a collimating mirror, a vibrating mirror, and a beam expander group arranged sequentially along the beam path. The input light is collimated by the collimating mirror and then enters the vibrating mirror. The vibrating mirror deflects the beam at different angles, and the reflected light emitted at different angles is emitted into the detection space through the beam expander group.

[0008] In a further improvement, a set of reflectors is provided between the vibrating reflector and the beam expander group. Each beam expander corresponds to one reflector. The reflected light from the vibrating reflector when it rotates to different angles is reflected by the reflectors to the beam expander group and then emitted into the detection space.

[0009] In a further improvement, the beam expander group has n beam expanders, and a set of reflectors is set between the vibrating reflector and each beam expander. Each reflector set has m reflectors. The reflected light from the vibrating reflector when it rotates to different angles is reflected by m reflectors and then emitted into the detection space through the beam expander group. Each beam expander and its corresponding reflector group form a channel to achieve n-channel switching, where n≥1 and m≥0.

[0010] The beneficial effects of this utility model are as follows: 1. Multi-channel switching of the radar is achieved through collimating mirror, galvanometer, reflector, and beam expander. Compared with the existing solution, it does not require the use of fiber optic switches, which reduces optical power loss caused by fiber coupling, reduces the fiber SBS effect, and better controls the consistency of the detection carrier-to-noise ratio of each channel.

[0011] 2. Compared with the rotating wedge mirror solution, it does not use a rotating motor, resulting in lower power consumption. Without a wedge mirror, there is no centrifugal force, which provides better resistance to environmental vibration and reduces the angle change due to thermal expansion and contraction. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of a first-order reflective space light switching telescope system.

[0014] Figure 2 This is a schematic diagram of a two-stage reflective space light switching telescope system.

[0015] Figure 3 This is a schematic diagram of a three-level reflective space light switching telescope system.

[0016] Figure 4 This is a schematic diagram of an n-channel m+1-level reflective space light switching telescope system. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0018] This invention proposes a telescope system for spatial light switching, which realizes multi-channel switching of radar through a collimating mirror, a vibrating mirror, a reflecting mirror (or a folding prism), and a beam expander group. Compared with the prior art, it does not require the use of fiber optic switches, has lower optical power loss, better consistency of the detection carrier-to-noise ratio of each channel, and does not use a rotating motor, resulting in lower power consumption.

[0019] like Figure 1The first-order reflective space light switching telescope system shown includes a collimating mirror, a vibrating mirror, and a beam expander group. The beam expander group includes a first beam expander, a second beam expander, a third beam expander, and a fourth beam expander, where 1) is the XZ plane and 2) is the YZ plane. First, the input beam is collimated by the collimating mirror. Then, the beam is deflected at different angles by adjusting the deflection angle of the vibrating mirror. Finally, the beam is emitted into the detection space through the multi-channel beam expander group, achieving multi-channel beam switching, including but not limited to 2-channel and 4-channel switching.

[0020] like Figure 2 The illustrated two-stage reflective space light switching telescope system includes a collimating mirror, a vibrating mirror, a mirror group, and a beam expander group. The mirror group includes a first mirror, a second mirror, a third mirror, and a fourth mirror. The beam expander group includes a first beam expander, a second beam expander, a third beam expander, and a fourth beam expander, where 1) is the XZ plane and 2) is the YZ plane. First, the input beam is collimated by the collimating mirror. Then, the beam is deflected at different angles by adjusting the deflection angle of the vibrating mirror. When the radar requires a large deflection angle, and the vibrating mirror's deflection angle cannot achieve this, the beam can be deflected twice by the mirror group to increase the exit deflection angle. Finally, the beam is transmitted into the detection space through the multi-channel beam expander group, achieving multi-channel beam switching, including but not limited to 2-channel and 4-channel switching.

[0021] The specific implementation method is as follows: when the galvanometer is deflected by an angle of 1, the light beam is incident on the first reflecting mirror, then deflected to the first beam expander, and then emitted into the detection space. When the galvanometer is deflected by an angle of 2, the light beam is incident on the second reflecting mirror, then deflected to the second beam expander, and then emitted into the detection space. When the galvanometer is deflected by an angle of 3, the light beam is incident on the third reflecting mirror, then deflected to the third beam expander, and then emitted into the detection space. When the galvanometer is deflected by an angle of 4, the light beam is incident on the fourth reflecting mirror, then deflected to the fourth beam expander, and then emitted into the detection space.

[0022] like Figure 3The illustrated three-stage reflective space light switching telescope system includes a collimating mirror, a vibrating mirror, a first mirror group, a second mirror group, and a beam expander group. The first mirror group includes a first mirror, a second mirror, a third mirror, and a fourth mirror. The second mirror group includes a fifth mirror, a sixth mirror, a seventh mirror, and an eighth mirror. The beam expander group includes a first beam expander, a second beam expander, a third beam expander, and a fourth beam expander. Where 1) is the XZ plane and 2) is the YZ plane. First, the input beam is collimated by the collimating mirror. Then, the beam is deflected at different angles by adjusting the deflection angle of the vibrating mirror. When the radar requires a large deflection angle that the vibrating mirror cannot achieve, the beam is deflected twice by the first mirror group. Simultaneously, to reduce the overall axial length, a second mirror group is added to deflect the beam three times. Finally, the beam is transmitted to the detection space via the beam expander group, achieving multi-channel beam switching, including but not limited to 2-channel and 4-channel switching.

[0023] This can be extended to an n-channel m+1-order reflective spatial light switching telescope system, such as... Figure 4 As shown, the beam expander group has n beam expanders. A set of reflectors is set between the vibrating reflector and each beam expander. Each reflector set has m reflectors. The reflected light from the vibrating reflector when it rotates to different angles is reflected by m reflectors and then emitted into the detection space through the beam expander group. Each beam expander and its corresponding reflector group form a channel to realize n-channel switching, where n≥1 and m≥0.

[0024] The specific implementation method is as follows: when the galvanometer deflects at an angle of 1, the beam is incident on the first reflecting mirror, then deflected onto the fifth reflecting mirror, then deflected onto the first beam expander, and then emitted into the detection space. When the galvanometer deflects at an angle of 2, the beam is incident on the second reflecting mirror, then deflected onto the sixth reflecting mirror, then deflected onto the second beam expander, and then emitted into the detection space. When the galvanometer deflects at an angle of 3, the beam is incident on the third reflecting mirror, then deflected onto the seventh reflecting mirror, then deflected onto the third beam expander, and then emitted into the detection space. When the galvanometer deflects at an angle of 4, the beam is incident on the fourth reflecting mirror, then deflected onto the eighth reflecting mirror, then deflected onto the fourth beam expander, and then emitted into the detection space.

[0025] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. In particular, for the device embodiments, the above descriptions are merely preferred embodiments of this utility model. Since they are fundamentally similar to the method embodiments, the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments. The above descriptions are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this utility model, without departing from the principle of this utility model, should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A telescope with spatial light switching capability, characterized in that: It includes a collimating mirror, a vibrating mirror, and a beam expander group arranged sequentially along the beam path. The input light is collimated by the collimating mirror and then enters the vibrating mirror. The vibrating mirror deflects the beam at different angles, and the reflected light emitted at different angles is emitted into the detection space through the beam expander group.

2. The telescope with spatial light switching according to claim 1, characterized in that: A set of reflectors is provided between the vibrating reflector and the beam expander group. Each beam expander corresponds to one reflector. The reflected light from the vibrating reflector when it rotates to different angles is reflected by the reflectors to the beam expander group and then emitted into the detection space.

3. The telescope with spatial light switching according to claim 1, characterized in that: The beam expander group has n beam expanders. A set of reflectors is set between the vibrating reflector and each beam expander. Each reflector set has m reflectors. The reflected light from the vibrating reflector when it rotates to different angles is reflected by m reflectors and then emitted into the detection space through the beam expander group. Each beam expander and its corresponding reflector group form a channel to achieve n-channel switching, where n≥1 and m≥0.

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