阅读说明：本技术 一种多波长激光束产生方法及装置 (Multi-wavelength laser beam generation method and device ) 是由 梁志国 武腾飞 于 2020-06-22 设计创作，主要内容包括：本发明公开的一种多波长激光束产生方法及装置,属于光电测量技术领域。本发明的装置主要由激光器、偏振分光镜、λ/2波片、声光调制器、光阑、透镜、平面反射镜、正弦信号源组成。本发明仅仅基于单波长的连续激光,用正弦波以频率调节方式控制声光调制器实现入射激光的波长变化,使用声光调制器多级衍射方式获得不同波长的激光光束,再使用透镜将其转化为平行光,经反射合束,从而获得包含多个波长分量的多波长激光束,完成以单波长激光束实现多波长激光束的产生。本发明结构简单、可靠,成本低廉、易实现。本发明不仅便于实现远程测距应用,还适用于其它一个激光器应对具有多个波长需求的工程应用场合。(The invention discloses a method and a device for generating a multi-wavelength laser beam, and belongs to the technical field of photoelectric measurement. The device mainly comprises a laser, a polarization spectroscope, a lambda/2 wave plate, an acousto-optic modulator, a diaphragm, a lens, a plane reflector and a sinusoidal signal source. The invention only uses the continuous laser with single wavelength, controls the acousto-optic modulator in a frequency adjusting mode by sine waves to realize the wavelength change of incident laser, obtains laser beams with different wavelengths in a multi-level diffraction mode by using the acousto-optic modulator, converts the laser beams into parallel light by using a lens, and combines the parallel light by reflection, thereby obtaining a multi-wavelength laser beam containing a plurality of wavelength components and completing the generation of the multi-wavelength laser beam by using the single-wavelength laser beam. The invention has simple and reliable structure, low cost and easy realization. The invention is not only convenient for realizing remote distance measurement application, but also suitable for engineering application occasions where one laser meets the requirements of multiple wavelengths.)

1. A method of generating a multi-wavelength laser beam, comprising: based on single-wavelength continuous laser, the sine wave is used for controlling the acousto-optic modulator in a frequency adjusting mode to realize wavelength change of incident laser, laser beams with different wavelengths are obtained in a multi-level diffraction mode of the acousto-optic modulator, then the laser beams are converted into parallel light by using a lens and are combined through reflection, so that a multi-wavelength laser beam containing a plurality of wavelength components is obtained, and the generation of the multi-wavelength laser beam is realized by the single-wavelength laser beam.

2. A multi-wavelength laser beam generating method according to claim 1, wherein: when multi-wavelength laser of 2-5 wavelength combined beams for laser ranging needs to be generated, the multi-wavelength laser beam generation method is characterized in that based on single-wavelength continuous laser, an acousto-optic modulator is controlled by sine waves in a frequency adjustment mode to achieve wavelength change of incident laser, a multi-level diffraction mode of the acousto-optic modulator is used for exciting five diffraction light wavelengths including-2 level, -1 level, 0 level, +1 level and +2 level, a diaphragm device is used for shielding and sorting the five diffraction light wavelengths, laser beams with two wavelengths, three wavelengths, four wavelengths and five wavelengths and having common beam characteristics are respectively generated, and correspondingly generated laser beams with two wavelengths, three wavelengths, four wavelengths and five wavelengths are used for achieving femtosecond laser ranging.

3. A multi-wavelength laser beam generating apparatus for realizing a multi-wavelength laser beam generating method according to claim 2, characterized in that: mainly comprises a laser (1), a polarization spectroscope (2), a lambda/2 wave plate (3), an acousto-optic modulator (4), a diaphragm (5), a lens (6), a plane reflector (7) and a sinusoidal signal source (8);

the single-wavelength continuous laser generated by the laser (1) passes through the polarization spectroscope (2) and the lambda/2 wave plate (3) to reach the acousto-optic modulator (4); setting the frequency of a sinusoidal signal source (8), and carrying out frequency shift control on the laser frequency passing through the acousto-optic modulator (4) to generate diffraction laser with five wavelengths of-2 level, -1 level, 0 level, +1 level and +2 level; when the laser passes through the diaphragm (5), the laser is subjected to beam gating by the diaphragm (5), the laser with 1-5 wavelength components is selected to pass through respectively, then the laser passing through the diaphragm (5) after gating is changed into parallel light through the lens (6), the parallel light reaches the plane reflector (7), the parallel light returns to the acousto-optic modulator (4) after being reflected by the plane reflector (7), the frequency shift and beam combination are carried out again by the acousto-optic modulator (4), the parallel light passes through the lambda/2 wave plate (3) and is reflected by the polarization spectroscope (2), a multi-wavelength laser beam (9) with the common beam characteristic of double wavelength, three wavelength, four wavelength and five wavelength is generated, and the output of the multi-wavelength laser beam (9) is realized.

4. A multi-wavelength laser beam generating apparatus according to claim 3, wherein: the mode of combining a convex lens and a plane mirror is used for realizing the beam combination of laser with a plurality of wavelengths.

5. A multi-wavelength laser beam generating apparatus according to claim 3, wherein: the fine adjustment of the magnitude of a plurality of laser wavelengths is realized simultaneously by using a sinusoidal frequency control mode.

6. A multi-wavelength laser beam generating apparatus according to claim 3, wherein: and a mode of gating control of one diaphragm (5) is used for realizing superposition beam combination of a plurality of different laser wavelengths.

Technical Field

The invention relates to a method and a device for generating a multi-wavelength laser beam, belonging to the technical field of photoelectric measurement.

Background

Laser measurement includes various types such as interference measurement and non-interference measurement, is commonly used for length measurement, distance measurement, morphology measurement, angle measurement and the like, and is also used for vibration measurement, speed measurement, motion measurement and the like. Among them, a multi-wavelength measurement method is used in many cases. As the multi-wavelength measurement system, there are two-wavelength and three-wavelength systems. When the dual-wavelength measurement mode is realized, besides using a dual laser, a nonlinear frequency doubling technology and a birefringent crystal technology are commonly used. However, in the application of femtosecond laser multi-wavelength ranging, two or three lasers with different wavelengths need to be strictly operated in a common optical path, so that the modes are difficult to realize and the effect is not ideal enough. The laser beam generated by the femtosecond laser technology contains a plurality of wavelength components sharing a light path, and the required conditions can be realized in principle and logic, but because the femtosecond laser pulse contains too many wavelength components, the power component of each single wavelength laser is lower, and the femtosecond laser pulse can be practically applied in short-distance measurement, but is not easy to realize remote distance measurement application.

Disclosure of Invention

The invention aims to provide a method and a device for generating a multi-wavelength laser beam, aiming at the problem that high-power multi-wavelength common light beams are difficult to realize in femtosecond laser three-wavelength ranging. The invention has the advantages of simple and reliable structure, low cost and easy realization.

The invention is realized by the following technical scheme.

The invention discloses a multi-wavelength laser beam generation method, which is based on single-wavelength continuous laser, controls an acousto-optic modulator in a frequency adjustment mode by using sine waves to realize wavelength change of incident laser, obtains laser beams with different wavelengths in a multi-level diffraction mode by using the acousto-optic modulator, converts the laser beams into parallel light by using a lens, and combines the parallel light by reflection, thereby generating a multi-wavelength laser beam containing a plurality of wavelength components.

Preferably, when multi-wavelength laser with 2-5 combined wavelengths for laser ranging needs to be generated, the multi-wavelength laser beam generation method disclosed by the invention is used for controlling an acousto-optic modulator in a frequency adjustment mode to realize wavelength change of incident laser based on single-wavelength continuous laser, exciting five diffracted light wavelengths including-2, 1, 0, 1 and 2 in a multi-level diffraction mode by using the acousto-optic modulator, shielding and sorting the diffracted light wavelengths by using an aperture device to respectively generate laser beams with two wavelengths, three wavelengths, four wavelengths and five wavelengths with common beam characteristics, and realizing femtosecond laser ranging by using correspondingly generated laser beams with two wavelengths, three wavelengths, four wavelengths and five wavelengths.

The invention also discloses a multi-wavelength laser beam generating device, which is used for realizing the multi-wavelength laser beam generating method and mainly comprises a laser, a polarization spectroscope, a lambda/2 wave plate, an acousto-optic modulator, a diaphragm, a lens, a plane mirror and a sinusoidal signal source.

The continuous laser with single wavelength generated by the laser passes through the polarization beam splitter and the lambda/2 wave plate to reach the acousto-optic modulator. The frequency of a sinusoidal signal source is set, the frequency shift control is carried out on the laser frequency passing through the optical modulator, and diffraction laser with five wavelengths of-2 level, -1 level, 0 level, +1 level and +2 level is generated. When the laser passes through the diaphragm, beam gating is carried out by the diaphragm, the lasers with 1-5 wavelength components are respectively selected to pass through, then the lasers passing through after being gated by the diaphragm are changed into parallel light through the lens and reach the plane reflector, the parallel light returns to the acousto-optic modulator after being reflected by the plane reflector, the lasers are subjected to frequency shift and beam combination by the acousto-optic modulator again, the parallel light passes through the lambda/2 wave plate and is reflected by the polarization beam splitter, multi-wavelength laser beams with the common beam characteristics of double wavelength, three wavelength, four wavelength and five wavelength are generated, and multi-wavelength laser beam output is achieved.

Preferably, the multi-wavelength laser beam generator further includes a mirror coupled to the convex lens to combine the laser beams having a plurality of wavelengths.

Preferably, on the basis of the multi-wavelength laser beam generation device, the fine adjustment of the magnitudes of the multiple laser wavelengths is realized simultaneously by using a sinusoidal frequency control mode.

Preferably, on the basis of the multi-wavelength laser beam generating device, the superposition and beam combination of a plurality of different laser wavelengths are realized by using a diaphragm gating control mode.

Has the advantages that:

1. the invention relates to a method and a device for generating a multi-wavelength laser beam, which are based on single-wavelength continuous laser, control an acousto-optic modulator in a frequency adjustment mode by a sine wave to realize the wavelength change of incident laser, obtain laser beams with different wavelengths in a multi-level diffraction mode by the acousto-optic modulator, convert the laser beams into parallel light by a lens, and combine the parallel light by reflection, thereby realizing the multi-wavelength laser beam containing a plurality of wavelength components.

2. The method and the device for generating the multi-wavelength laser beam only generate the multi-wavelength laser with a plurality of wavelength combined beams based on the laser with a single wavelength, use sine frequency to regulate and control wavelength change, and have the advantages of simple and reliable structure, low cost and easy realization. One laser can be used to address engineering applications with multiple wavelength requirements. In addition, the multi-wavelength laser generated by the invention can be taken out after the lens without beam combination and used respectively, so that the application of the multi-wavelength laser is more flexible.

3. According to the method and the device for generating the multi-wavelength laser beam, the adjustment fineness and the frequency accuracy of the sine frequency are high, the correspondingly obtained wavelength adjustment fineness is also very high, and the fine adjustment of the wavelength component of the measuring beam can be realized.

Drawings

Fig. 1 is a schematic structural diagram of a multi-wavelength laser beam generating apparatus according to the present invention.

Wherein: 1-laser, 2-polarizing spectroscope, 3-lambda/2 wave plate, 4-acousto-optic modulator, 5-diaphragm, 6-lens, 7-plane reflector, 8-sine signal source and 9-multi-wavelength laser beam.

Detailed Description

For a better understanding of the objects and advantages of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings and examples.