Multipass optical path device for eliminating laser speckles based on random phase mask and operating method of multipass optical path device for eliminating laser speckles based on random phase mask

Abstract

The invention discloses a multipass optical path device for eliminating laser speckles based on a random phase mask and an operating method of the multipass optical path device for eliminating the laser speckles based on the random phase mask. The multipass optical path device for eliminating the laser speckles based on the random phase mask is provided with a laser light source and is characterized in that a single mode fiber, a collimation and beam expanding system, a multipass optical path modulation device and a semi-reflective and semi-transparent lens are arranged on an optical path, the optical path behind the semi-reflective and semi-transparent lens is divided into two branches, one branch is composed of a focusing lens and a CCD-A detector, and the other branch is composed of a microobjective, a multimode fiber and a CCD-B detector; the multipass optical path modulation device structurally comprises a first plane mirror, a high-reflectance plane mirror A, a high-reflectance plane mirror B and a second plane mirror, the high-reflectance plane mirror A and the high-reflectance plane mirror B are arranged in pair, and the phase mask which is driven by a rotary motor is arranged between the high-reflectance plane mirror A and the high-reflectance plane mirror B which are arranged in pair and controlled by a power supply and a rotation speed control device. By the adoption of the multipass optical path device for eliminating laser speckles based on the random phase mask, the irrelevance between the laser speckles is greatly improved. The manufacturing technology is simple, the structure can be designed conveniently, the light beam passing rate is high, energy loss is small, and the remanufacturing can be achieved easily. The multipass optical path device for eliminating the laser speckles based on the random phase mask can be applied to the fields such as the laser projection display field and the laser lighting field, thereby being wide in application range.

Description

Technical field: [0001] The invention belongs to the field of laser detection and optical imaging, and relates to a device for multi-frequency phase modulation of incident light beams and elimination of laser speckles based on a random phase plate multi-pass optical path design structure. The invention also relates to the method of operation of such a device. Background technique [0002] Due to its high brightness, high coherence and high collimation, laser has played a unique and vital role in the fields of industry, military, communication, medicine, scientific research and social life. When the laser is irradiated on a rough surface or propagates in a medium with irregular refractive index fluctuations, every point on the rough surface will scatter light, and these highly coherent beams with different amplitudes and phases form infinite Regularly distributed granular speckle - laser speckle. [0003] As a random process, laser speckle is an objective physical phenomeno...

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Problems solved by technology

Chinese Patent CN 102122081A discloses "Laser Beam Homogenization and Shaping Dispersion Speckle Device", which uses a pure phase diffraction device to complete the functions of uniform light shaping and speckle elimination under the drive of an electromagnetic vibration device; Chinese Patent CN101950087A discloses "A Laser Speckle Elimination The method of the laser speckle effect is to eliminate the laser speckle effect by passing the incident beam through a vibrating light-transmitting liquid to destroy the beam phase; when using the dynamic speckle method, the faster the speckle change frequency,

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