Continuous-wave 1.5-micron all-solid-state self-Raman laser safe for human eyes

Abstract

The invention discloses a continuous wave 1.5 [mu] m human eye safe all-solid-state self-Raman laser which comprises a laser diode pumping source, a collimation focusing coupling system, an input cavity mirror, a self-Raman crystal and an output cavity mirror. Pump light emitted by a laser diode pumping source is amplified and focused by the collimation focusing coupling system and then enters the self-Raman crystal through the input cavity mirror, the self-Raman crystal is subjected to population inversion and generates laser radiation, and fundamental frequency laser oscillation with the wave band of 1.3 microns is formed in a laser cavity formed by the input cavity mirror and the output cavity mirror. When the power density of the 1.3-micron-band fundamental frequency laser in the laser cavity reaches a Raman conversion threshold value, the 1.3-micron-band fundamental frequency laser generates continuous wave 1.5-micron-band Raman laser through Raman frequency shift of the self-Raman crystal, and the continuous wave 1.5-micron-band Raman laser is output from the output cavity mirror. The laser has the characteristics of simple and compact structure, high light conversion efficiency and low threshold value.

Description

technical field [0001] The invention relates to a laser, in particular to an all-solid-state self-Raman laser. Background technique [0002] Lasers in the 1.5 μm band are eye-safe and have low transmission loss in the atmosphere and glass media, so they have important applications in optical communications, lidar, medicine, remote sensing, laser ranging and other fields. Stimulated Raman scattering (stimulatedRaman scattering, SRS) is an effective laser frequency conversion technology. The all-solid-state Raman laser uses the SRS effect of the crystal medium to shift the Raman frequency of the 1.3 μm fundamental frequency laser output by common solid-state lasers to the 1.5 μm band to obtain eye-safe laser output, and because the SRS process also has a beam purification effect, it is obtained Compared with the original 1.3μm fundamental frequency light, the 1.5μm Raman laser has better beam quality, narrower pulse width and spectral linewidth. Since stimulated Raman scatte...

AI Technical Summary

Problems solved by technology

However, when the frequency shifts from 1.3 μm to 1.5 μm, the laser and Raman gains of the crystal are small, and the thermal effect of the crystal is more serious, resulting in a further decrease in the laser and Raman gains, so the Raman conversion threshold of this band is higher

At present, only pulsed all-solid-state Raman lasers can reach the 1.5 μm Raman conversion threshold due to their high fundamental frequency peak power, and have successfully achieved the output of 1.5 μm human eye-safe pulsed Raman lasers, but continuous wave 1.5 μm human The output of eye-safe Raman lasers has not yet been realized

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