Microchip Nd:YAG and Nd:YVO4 Lasers Pumped by VHG Wavelength-Stabilized Laser Diode

T Saiki,A Tatebayashi

doi:10.1155/2020/3952435

Abstract

We adopted a single-mode, single-wavelength volume holographic grating (VHG) wavelength-stabilized wavelength laser diode (LD) as a pumping LD for an end-pumped microchip Nd:YAG and Nd:YVO4 lasers we developed during CW and pulse operations. Higher optical-optical and slope efficiencies during CW operation have been obtained than when using a VHG LD experimentally. Output laser power is insensitive to the temperature of the LD when using a wavelength-stabilized LD and can remain stable and almost constant until the temperature of LD increases up to 40°C. The improved optical-optical conversion efficiency of 58% for the Nd:YVO4 laser has been obtained and calculated the output laser power during CW operation and compared it with the experimental results. We found that the output laser power of the Nd:YVO4 laser using the VHG wavelength-stabilized LD was more than twice as high as that using an LD without VHG. When the ambient temperature increases, the difference in output laser power should be large. In the future, a low-cost end-pumped microchip laser that does not require a temperature control should be developed.

Highlights

Solid-state lasers are compact and efficient and have high beam quality, and the application of laser diode- (LD-) pumped lasers to the industrial field has expanded
Neodymium-doped yttrium aluminum garnet (Nd:YAG) crystals have been used as laser media for microchip lasers; the absorption bandwidth for the pump light is as narrow as 2.5 nm [17], and when the temperature of the LD increases, the peak wavelength of the output light shifts to the longer wavelength side, so LD temperature should be controlled. us, the cost of laser systems increases
For the Nd:YAG laser using the LD without volume holographic grating (VHG), we found that the absorption rate decreased by 30% compared to that at 24°C when the temperature increased to 35°C

Summary

Introduction

Solid-state lasers are compact and efficient and have high beam quality, and the application of laser diode- (LD-) pumped lasers to the industrial field has expanded. For the Nd:YVO4 laser using the LD without VHG, the absorption rate decreased by 20% when the temperature increased to 35°C For this laser using the VHG LD, the absorption rate did not decrease up to 35°C. e output laser power was maintained owing to the broad effective absorption bandwidth at the pumping wavelengths of the Nd:YAG and Nd:YVO4 crystals, which are 2.5 and 15.7 nm, respectively [17].

With VHG LD

Conclusion