Advances in All-Solid-State Passively Q-Switched Lasers Based on Cr4+:YAG Saturable Absorber

Jingling Tang,Duo Zhang,Zhenxu Bai,Jie Ding,Yulei Wang,Zhiwei Lu,Yaoyao Qi

doi:10.3390/photonics8040093

Jingling Tang, Duo Zhang + Show 5 more

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https://doi.org/10.3390/photonics8040093

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Journal: Photonics	Publication Date: Mar 27, 2021
Citations: 12	License type: CC BY 4.0

Affiliation: Hebei University of Technology, Macquarie University

Abstract

All-solid-state passively Q-switched lasers have advantages that include simple structure, high peak power, and short sub-nanosecond pulse width. Potentially, these lasers can be applied in multiple settings, such as in miniature light sources, laser medical treatment, remote sensing, and precision processing. Cr4+:YAG crystal is an ideal Q-switch material for all-solid-state passively Q-switched lasers owing to its high thermal conductivity, low saturation light intensity, and high damage threshold. This study summarizes the research progress on all-solid-state passively Q-switched lasers that use Cr4+:YAG crystal as a saturable absorber and discusses further prospects for the development and application of such lasers.

Highlights

All-solid-state passively Q-switched lasers have the characteristics of simple structure, small size, and broad application potential in areas, such as high-precision processing, laser medical treatment, and laser communication
Using Q-switched lasers with Cr4+ :YAG crystal as the saturable absorber can provide high peak power, large pulse energy, high beam quality, and sub-nanosecond pulse width. They have the potential to be widely used in various fields, including high-precision laser processing, space exploration, laser medical treatment, and material analysis
To reduce the lasing threshold, the saturable absorber is placed near the beam waist of the resonator for higher power density to reach the saturated absorption

Summary

Introduction

All-solid-state passively Q-switched lasers have the characteristics of simple structure, small size, and broad application potential in areas, such as high-precision processing, laser medical treatment, and laser communication. When compared with other saturable absorbers, Cr4+ :YAG crystal has the advantages of large ground-state absorption cross-section (~10−18 cm2 ), high doping concentration (~1018 cm−3 ), good thermal conductivity, low saturated light intensity, high damage threshold (500 MW/cm2 ), stable physical properties, and long service life. It is an ideal Q-switch material for Nd3+ -doped and Yb3+ -doped solid-state lasers [4].

Nd -DopedPassively

Passively Q-Switched Green Lasers

Passively Q-Switched Raman Lasers

Passively Q-Switched Vortex Lasers

Experimental setup of passive

Brief Summary

Summary and Outlook