Speckle laser device based on low time coherence and low spatial coherence and preparation method thereof

Abstract

The invention discloses a speckle laser device based on low time coherence and low spatial coherence and a preparation method thereof.The speckle laser device comprises a radio frequency modulator, a laser device body, a diffracting optical element and a focusing lens which are coaxially and sequentially arranged on the same optical platform.The diffracting optical element is located in the emergent direction of the laser device, the radio frequency modulator modulates the laser device body, and laser modulated by the radio frequency modulator enters the diffracting optical element.Laser beams emerging from the diffracting optical element are zero-coherent speckle laser beams, the laser beams enter the focusing lens, and the laser emerging from the focusing lens form focused speckle laser.By the adoption of the speckle laser device based on low time coherence and low spatial coherence and the preparation method, speckle laser output beams are obtained by adopting a time coherence and spatial coherence reducing technology, and the problem of speckle production due to time coherence and spatial coherence is solved.

Description

technical field [0001] The invention relates to the technical field of lasers, in particular to a zero-speckle laser with lower than low temporal coherence and low spatial coherence and a preparation method thereof. Background technique [0002] Due to its high brightness, high coherence and high collimation, laser has a wide range of applications in industry, communication, medical treatment, laser detection and measurement, instrumentation, etc. The laser has highly coherent beams with different amplitudes and phases, forming irregularly distributed granular patterns at various points in space --- laser speckle. As a random process, laser speckle is an objective physical phenomenon that must exist with the use of lasers. Laser speckle not only causes energy loss, but also becomes the main factor that limits image quality and reduces image resolution and contrast. For example, in the field of research and application of laser projection display and laser lighting, laser sp...

AI Technical Summary

Problems solved by technology

When using the dynamic speckle method, the faster the speckle change frequency, the smaller the correlation between the speckles, and the better the speckle suppression effect after time averaging. However, the current dynamic speckle method has a complex structure and poor system stability.

At present, in speckle elimination, the control range of speckle frequency is limited, and the depth of phase adjustment is small, which makes the speckle correlation greater. The above factors reduce the effect of speckle suppression. Large, and accompanied by the phenomenon of angular expansion, which affects the performance of the system

[0005] To sum up, both the static speckle reduction method and the dynamic speckle reduction method start from the laser (or laser) itself to reduce the impact of laser speckle on system performance. In the process, these two methods only reduce laser speckle The impact of speckle on the performance of the system cannot be easily reduced (or compensated) from further real-time evaluation and measurement systems to obtain image data with low speckle impact and high signal-to-noise ratio

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