CN112285671A

CN112285671A - Two-dimensional scanning device based on photoswitch

Info

Publication number: CN112285671A
Application number: CN202011158466.6A
Authority: CN
Inventors: 黄锦熙; 巩少斌
Original assignee: Hangzhou Opto Semiconductor Technology Co Ltd
Current assignee: Hangzhou Opto Semiconductor Technology Co Ltd
Priority date: 2020-10-26
Filing date: 2020-10-26
Publication date: 2021-01-29

Abstract

A two-dimensional scanning device based on an optical switch belongs to the technical field of scanning devices and comprises a laser output unit, a laser scanning unit and a laser scanning unit, wherein the laser output unit outputs a divergent laser beam; the coupling lens is used for coupling the divergent laser beams into a point light source; the optical switch receives the point light source to perform time sequence multi-channel output; the collimation system is used for collimating the divergent light output by the light receiving switch into parallel light and emitting the parallel light; the grating is used for emitting the parallel light collimated by the collimating system to the beam expanding system according to different diffraction angles; the beam expanding system receives the laser output by the grating, changes the divergence angle of the light beam and enlarges the scanning range of the laser; the invention realizes pure solid two-dimensional scanning by adopting the optical switch in combination with the laser output unit and the grating, simplifies the structure of the scanning device, and simultaneously ensures the scanning accuracy and stability by adopting the pure solid two-dimensional scanning mode.

Description

Two-dimensional scanning device based on photoswitch

Technical Field

The invention belongs to the technical field of scanning devices, and particularly relates to a two-dimensional scanning device based on an optical switch.

Background

Lidar is a device that uses a laser beam to search for, track, and accurately determine the azimuth, range, and velocity of a target. Compared with a microwave radar, the laser radar has the advantages of high resolution, good hiding performance, good low-altitude detection performance, small volume, light weight and the like. The existing mature laser radar has a mechanical scanning radar and a non-scanning radar; the scanning laser radar occupies a relatively large market share at present; the scanning type laser radar is two types from the prior art, one type is mechanical scanning, a mirror surface is driven to rotate by a motor, the deflection of a light beam is realized by utilizing the principle of geometric optics, and a three-dimensional point cloud picture is scanned; the scanning mode can be calculated as a point scanning mode, and has the defects of low resolution ratio, capability of only distinguishing a large object at a long distance and large volume.

Comparatively common laser radar all is provided with rotary mechanism in the market at present, drives the scanning mirror through rotary mechanism and combines the grating to carry out two-dimensional scanning, and this type of design is comparatively complicated, and in the scanning process because rotary equipment rotates and leads to the scanning result to be accurate inadequately easily.

Disclosure of Invention

The present invention is directed to a two-dimensional scanning device based on an optical switch, so as to solve the problems mentioned in the background art.

In order to achieve the purpose, the invention provides the following technical scheme:

a two-dimensional scanning device based on an optical switch comprises a laser output unit, a laser scanning unit and a control unit, wherein the laser output unit outputs a divergent laser beam; the coupling lens is used for coupling the divergent laser beams into a point light source; the optical switch receives the point light source to perform time sequence multi-channel output; the collimation system is used for collimating the divergent light output by the light receiving switch into parallel light and emitting the parallel light; the grating is used for emitting the parallel light collimated by the collimating system to the beam expanding system according to different diffraction angles; and the beam expanding system receives the laser output by the grating, changes the divergence angle of the beam and expands the scanning range of the beam.

Compared with the prior art, the invention has the beneficial effects that: the invention realizes pure solid two-dimensional scanning by adopting the optical switch in combination with the laser output unit and the grating, simplifies the structure of the scanning device, and simultaneously ensures the scanning accuracy and stability by adopting the pure solid two-dimensional scanning mode.

Further, the laser output unit adopts a tunable laser.

Further, the grating is one of a holographic grating or a diffraction grating.

Further, the collimation system is composed of one of a micro lens array or a lens assembly.

Furthermore, the lens component comprises a plurality of cylindrical lenses, the cylindrical lenses are arranged at the light-emitting ends of the output channel of the optical switch in a one-to-one correspondence manner, namely, one cylindrical lens is arranged at each light-emitting end at intervals.

Furthermore, the beam expanding system comprises not less than two prisms, and the two prisms are arranged at intervals.

Drawings

FIG. 1 is a schematic diagram of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described below in detail and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments.

Example (b):

as shown in fig. 1, a two-dimensional scanning device based on an optical switch is sequentially provided with a laser output unit, a coupling lens 1, an optical switch 2, a collimating system 3, a grating 4 and a beam expanding system 5 in order according to an optical path.

In this embodiment, the laser output unit adopts a tunable laser to output a divergent laser beam; secondly, the coupling lens 1 couples the divergent laser beams into a point light source; the light to be diffused is converged, so that the light completely enters the optical switch 2, the utilization rate is improved, the optical switch 2 receives a point light source for time sequence multi-channel output, and the collimation system 3 receives the diffused light output by the optical switch 2 and collimates the diffused light into parallel light to be emitted; the grating 4 is used for emitting the parallel light collimated by the collimating system 3 to the beam expanding system 5 according to different diffraction angles; the beam expanding system 5 is used for receiving the laser output by the grating 4, changing the divergence angle of the light beam and expanding the scanning range of the laser; specifically, the optical switch 2 is electrically connected to a timing controller, so that the light sources are sequentially output from different output channels of the optical switch 2, and the scanning in the first direction is realized by combining with the subsequent grating 4; secondly, the wavelength of incident laser is adjusted through the tunable laser, small-angle scanning in the second direction is achieved, the beam expanding system is combined, the scanning range in the second direction is enlarged, and therefore the accuracy of scanning detection results is improved.

It is noted that the grating 4 is one of a holographic grating and a diffraction grating.

In addition, the collimating system 3 is composed of one of a micro lens array or a lens assembly, wherein the lens assembly includes a plurality of cylindrical lenses, the plurality of cylindrical lenses are arranged at the light emitting ends of the output channels of the optical switch 2 in a one-to-one correspondence manner, that is, one cylindrical lens is arranged at each light emitting end at intervals.

Meanwhile, the beam expanding system 3 comprises not less than two prisms which are arranged at intervals.

The working principle of the invention is as follows: by adopting a tunable laser, laser enters the optical switch 2 through coupling, the characteristic of the optical switch 2 is divided into a plurality of paths, an output path is selected according to a time sequence control instruction, the optical switch 2 is parallel to the incident light plane of the grating 4, namely, the optical switch 2 is horizontally arranged, the plurality of paths are switched along the horizontal direction, and emergent light passes through the collimating system 3 and then enters the surface of the grating 4. When the optical switch 2 switches the channel continuously, the incident angle of the light incident on the surface of the grating 4 through the collimation system 3 changes, and the horizontal scanning angle in the corresponding emergent object space also changes, so that the scanning in the horizontal direction is completed. Meanwhile, the laser is tunable in wavelength, the wavelength is changed, and a small-angle scanning angle is formed in the vertical direction due to different diffraction angles after the laser is incident on the surface of the grating 4, so that the scanning in the vertical direction is completed. The two scans can be performed simultaneously, thereby realizing pure solid state laser scanning.

In the description of the present invention, it is to be understood that the terms "center", "lateral", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified. Furthermore, the term "comprises" and any variations thereof is intended to cover non-exclusive inclusions.

The present invention has been described in terms of embodiments, and several variations and modifications can be made to the device without departing from the principles of the present invention. It should be noted that all the technical solutions obtained by means of equivalent substitution or equivalent transformation, etc., fall within the protection scope of the present invention.

Claims

1. A two-dimensional scanning device based on photoswitch is characterized in that: comprises that

A laser output unit outputting a divergent laser beam;

a coupling lens (1) for coupling the divergent laser beams into a point light source;

the optical switch (2) receives the point light source to perform time sequence multi-channel output;

the collimation system (3) is used for receiving the divergent light output by the optical switch (2) and collimating the divergent light into parallel light to be emitted;

the grating (4) is used for emitting the parallel light collimated by the collimating system (3) to the beam expanding system (5) according to different diffraction angles;

and the beam expanding system (5) receives the laser output by the grating (4), changes the divergence angle of the beam and expands the scanning range of the laser.

2. An optical switch-based two-dimensional scanning device according to claim 1, wherein: the laser output unit adopts a tunable laser.

3. An optical switch-based two-dimensional scanning device according to claim 2, wherein: the grating (4) is one of a holographic grating or a diffraction grating.

4. An optical switch-based two-dimensional scanning device according to claim 1, wherein: the collimation system (3) is constituted by one of a micro-lens array or a lens assembly.

5. An optical switch-based two-dimensional scanning device according to claim 4, wherein: the lens component comprises a plurality of cylindrical lenses, the cylindrical lenses are arranged at the light emitting ends of the output channels of the optical switch (2) in a one-to-one correspondence mode, namely, one cylindrical lens is arranged at each light emitting end at intervals.

6. A two-dimensional scanning device based on optical switching according to claim 1, characterized in that: the beam expanding system (3) comprises not less than two prisms, and the prisms are arranged at intervals.