2.7-3 μm mid-infrared laser has important applications in spectroscopy, gas detection, laser medicine and optical parametric oscillator pumping source etc. Recently, under the financial support of the National Natural Science Foundation of China, Prof. Dunlu SUN’s group from Crystal lab, Laser center, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences (CAS), has achieved a series of new progresses on the exploring of high efficiency and radiation resistant 2.7-3 μm mid-infrared laser crystals, the related results have been published in the recent Optics Letters and Optics Express journals of Optical Society of America (OSA).
On the study of radiation resistant property of laser crystals, a comparable investigation was demonstrated on the absorption, fluorescence spectra, level lifetime and laser characteristics for the Er:GYSGG and Yb,Er,Ho:GYSGG crystals before and after 100 Mrad 60Co γ-ray irradiation. The results show that the novel crystals have excellent radiation resistance ability (Optics Letters,2013,38:1218-1220).
In order to improve the laser efficiency and laser performance under high repetition frequency for the mid-infrared laser crystals, through the doping of deactivator ions Pr3+, Ho3+ and sensitization ions Yb3+, Cr3+, the influences on the 2.7~3 μm absorption, fluorescence, level lifetime and laser performance were investigated. These results suggest that doping deactivator ions can decrease effectively the lower laser level lifetime, improve the laser efficiency and laser performance at high repetition rate, which lay an important foundation for their practical application (Optics Letters,2015,40:4194-4197; Optics Express,2013,21: 23425-23432).
In addition, in recent years, this group has been working on the thermal bonding techniques and related performance investigation about the composite laser crystal. The results show that the GYSGG/Er,Pr:GYSGG composite crystal bonded by thermal diffusion technology has great advantages in reducing thermal lensing, thermal distortion effects and improving laser performances, and a composite GYSGG end cap is a suitable cooling structure for efficient and high-power operation of diode end-pumped solid-state lasers(Optics Express, 2014,22:23795-23800).
This work was funded by The General Project (50872135) and Major Research Plan Breeding Project (91122021) of The National Natural Science Foundation of China.
Keywords: Er:GYSGG; Mid-infrared laser; Radiation resistant; Deactivator; Thermal bonding
The paper linked:
Spectroscopic and diode-pumped laser properties of Yb,Er,Ho:GYSGG radiation resistance crystal
Growth, spectroscopic and laser performances of 2.79 μm Cr,Er,Pr:GYSGG radiation-resistant crystal
Spectroscopic properties and diode end-pumped 2.79 μm laser performance of Er,Pr:GYSGG crystal
Performances of a diode end-pumped GYSGG/Er,Pr:GYSGG composite laser crystal operated at 2.79 μm
Fig.1 Output power versus input power for different output mirror transmissions and 100 Mrad γ-ray radiation
Fig.2 Output pulse energy versus pumping energy operated at 1~60 Hz
Fig.3 Fluorescence decay curves of the Er,Pr:GYSGG crystal
Fig.4 Temperature distribution on the pump end-face of the two crystals. (a) Er,Pr:GYSGG; (b) GYSGG/Er,Pr:GYSGG
Fig.5 Output power versus pump power for the two crystals