Method and laser for generating low-coherence light beam with vector special spatial correlation structure

Abstract

The invention relates to a method and laser for generating vector special spatial correlation structure low-coherent light beams. The laser comprises a holophote 1, a work substance 2, an excitation source 10, a Brewster window 3, a liner polarizing film 4, a half wave plate 5, polarizing beam splitters 6 and 15, beam expanders 7 and 11, thin lenses 8, 12 and 16, an amplitude attenuator 13, coated mirrors 9 and 14 and a coupling output mirror 17. A 4f optical system is installed in a Fabry-Perot cavity, a degenerate cavity is formed, and part of coherent light beams are directly output; the area of a light intensity attenuation area is controlled through the coated mirrors, and the coherence degree of the output light beams is changed; the size of spots on the coated mirrors is controlled by adjusting the beam expanders, the reflecting modulus is controlled, and coherence is adjusted. An improved Mach-Zehnder interferometer is used for generating different vector light beams; the coated mirrors are placed on the frequency spectrum face of the 4f optical system, different kinds of modulation are carried out on the frequency spectrum face, and the output light beams with different kinds of special spatial correlation structure distribution are obtained.

Description

technical field [0001] The invention relates to the field of lasers, in particular to a method and a laser for generating low-coherence light beams with a variety of vector special spatially correlated structures. role. Background technique [0002] Since the appearance of laser, it has been widely used in military, civilian and scientific research fields. The beam from the laser is considered to be a completely coherent beam, but strictly speaking it should be called a high-coherence beam, which is also one of the four characteristics of the laser. However, in practical applications, it is found that the high-coherence beam will bring some applications. Negative impact, because the higher the coherence, the easier it is to cause interference in the transmission process, resulting in speckle, which is a huge hindrance to high-quality imaging, laser coating and other applications, so the study of partially coherent (low coherent) beams has become a One of the hottest studie...

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Problems solved by technology

However, the high cost price, low threshold power and low efficiency of the spatial light modulator, and the instability of the mechanical jitter of the frosted glass will inevitably hinder its high-power and other practical applications, such as military applications.

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