Mechanical-electrical compound dimming system for laser beam quality analyzer

Abstract

The invention provides a mechanical-electrical compound dimming system for a laser beam quality analyzer. The mechanical-electrical compound dimming system comprises a single-wheel variable optical attenuator, a CCD (charge coupled device) camera, a stepping motor, an electrical control system and a PC (personal computer). For an acquired image, an incident laser beam passes the single-wheel variable optical attenuator and is attenuated after shutter time is preset by the CCD camera, a new acquired spot image is processed by the PC, the electronic shutter time slot of the CCD camera is adjusted by the electrical control system according to a gray value, incident laser intensity is continuously attenuated by the aid of the single-wheel variable optical attenuator, linearity is fine, the dynamic range is wide, and a laser beam quality analyzer attenuation module is small in size and convenient to use. The dimming range of traditional optical wedge continuous attenuation of light intensity in the laser beam quality analyzer is narrow and is about 20-300 times, and the dimming system obtains the wide dynamic dimming range of 5000 times.

Description

technical field [0001] The invention belongs to the field of optoelectronic technology, and relates to an electromechanical composite dimming system for a laser beam quality analyzer. A mechanical single-wheel variable optical attenuator is cascaded with an electronic shutter of a CCD camera to realize continuous attenuation of laser light intensity. Background technique [0002] In the research of the laser beam parameter measurement and evaluation system using the laser beam quality analyzer, due to the high sensitivity and low saturation light intensity of the area array CCD detection device, the aberration-free continuous attenuation of the measured beam becomes a key point in the measurement process. technology. Commonly used continuous dimming technologies mainly include: mechanical diaphragm continuous dimming technology, photoelectric continuous dimming technology, continuous dimming technology using absorption gradient attenuation film and crystal absorption continu...

AI Technical Summary

Problems solved by technology

Among them, the mechanical aperture continuous dimming technology realizes the spatial attenuation of the beam through the variable aperture method. It is small in size, fast in speed, low in power consumption, and relatively mature in technology, but has a small dynamic range and low linearity. Not good, it is not easy to realize cascading work; photoelectric continuous dimming technology includes Faraday rotation, electro-optic crystal dimming and liquid crystal dimming, the dynamic range is small when realized, cascading work is required, dimming nonlinearity is serious, and closed-loop compensation is required to improve accuracy. It is not suitable for wide-range and high-precision dimming; continuous dimming can be realized by using an absorption gradient attenuator, which can realize wide-range and continuous dimming. It is easy to produce speckles when cascading; crystal absorption method continuous dimming technology can realize a wide range of light intensity adjustment, but the adjustment accuracy depends on the uniformity of the material and the control accuracy of the lead screw

In the existing laser beam quality analysis system, the laser energy continuous attenuation technology adopts the double mechanical diaphragm continuous dimming technology, which has the defects of small dynamic range and poor linearity; Continuous dimming technology, there are problems of poor linearity and laser speckle, which affect the analysis results of beam quality

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