High-light pulse type pseudo-thermal light source

Abstract

A high-brightness pulsed pseudothermal light source, which consists of a pulsed laser, a beam expander collimation system, a pinhole filter, an adjustable aperture stop, a frosted glass disc and a speed-regulating motor, the pulsed laser, beam expander The collimation system, the pinhole filter and the adjustable aperture stop are on the same optical axis, the pinhole filter is placed on the focal plane of the telescope of the beam expander collimation system, and the laser output from the pulsed laser Finally, it is irradiated on the frosted glass disk driven by the speed-adjusting motor to form a dynamic speckle field, which is the pseudo-thermal optical field. The thermal fluctuation of the pseudothermal optical field of the high-brightness pulsed pseudothermal light source of the present invention can be truly recorded by the photoelectric detection system with a limited passband, and is not affected by the passband of the photoelectric detection system used, meeting the requirements of the real thermal optical field Cross Spectrum Purity Conditions.

Description

technical field [0001] The invention relates to a thermo-optical field, in particular to a high-brightness pulse type pseudo-thermal light source. Background technique [0002] The coherence time for thermal light is short, even for the quasi-monochromatic light emitted by the best line spectrum light source, the coherence time can only reach 10 -11 ~10 -10 Second. However, the existing photodetectors have the fastest response to reach 10 -9 Second. Therefore, the instantaneous intensity of thermo-optical fluctuations cannot be measured with existing photodetectors. So in 1964 a continuous pseudothermal light source was developed [see W.Martienssen, and E.Spiller, "Coherence and Fluctuations in Light Beams," American Journal of Physics 32, 8(1964).]. The existing pseudothermal light source is realized by irradiating the rotating frosted glass with continuous laser light, and the dynamic speckle field formed by scattering of the ground glass is the generated pseudotherma...

AI Technical Summary

Problems solved by technology

[0003] 1. The limited passband of the photoelectric detection system leads to the loss of high-frequency components of pseudothermal optical field fluctuations, so the optical field fluctuation information recorded by the detection system is not a real record;

[0004] 2. The continuous pseudothermal light source does not meet the cross-spectral purity conditions of the real thermal-optical field, so it cannot completely simulate the real thermal-optical field; the so-called cross-spectral purity condition means that the complex coherence of the thermal-optical field can be decomposed into time-complex The product form of coherence degree and spatial complex coherence degree

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