Cr<3+>:KMgSc(WO4)3 doped tunable laser crystal and method for preparing same

Abstract

The invention provides a Cr<3+>:KMgSc(WO4)3 doped tunable laser crystal and a method for the crystal. The crystal belongs to the trigonal system and has the space group as descried in the description and the following cell parameters: a=9.493A, C=24.545A, V=1915.68A<3>, Z=6 and Dc=4.412g / cm<3>. The crystal can be grown by using flux growth method, wherein the 60-80at% K2W2O7 is used as flux, the temperature decreasing speed is 1-5 DEG C per day, and the rotating speed is 5-30rpm. The high-quality large-size Cr<3+>:KMgSc(WO4)3 crystal has the tunable range of 710-1300nm and is expected to become a novel tunable laser crystal for practical application.

Description

technical field [0001] The invention relates to the technical field of optoelectronic functional materials, in particular to a laser crystal material used as a working substance in a tunable solid-state laser. Background technique [0002] Tunable laser refers to such an effect: the pump excites the active ions doped in the solid-state laser matrix to generate laser light, using prism tuning method, F-P etalon tuning method, grating tuning method, filter tuning method and distributed feedback System tuning method, etc. to obtain tunable laser output. [0003] In 1963, L.F. Johnson and others used flash lamp pumping, doped with Ni 2+ MgF 2 The first solid-state tunable laser operation was realized in a crystal (L.F. Johnson R.E. Dietz & H.J. Guggenheim, J.Phys. Rev. Lett., 11(1963) 318). Subsequently, many tunable laser crystals appeared, such as Ti 3+ :Al 2 o 3 、Cr 3+ :Mg 2 SiO 4 、Cr 3+ :LiSrAlF 6 、Cr 3+ :BeAl 2 o 4 etc., but due to various reasons, many tunabl...

AI Technical Summary

Problems solved by technology

Subsequently, many tunable laser crystals appeared, such as Ti 3+ :Al 2 o 3 、Cr 3+ :Mg 2 SiO 4 、Cr 3+ :LiSrAlF 6 、Cr 3+ :BeAl 2 o 4 etc., but due to various reasons, many tunable laser crystals are limited to laboratory tools and cannot be promoted to industrial applications

The tunable laser crystal that has been studied the most and has entered the application field is Cr 3+ :BeAl 2 o 4 (Alexandrite), Ti 3+ :Al 2 o 3 (titanium-doped sapphire) and Cr 3+ :LiCaAlF 6 、Cr 3+ :LiSrAlF 6 , but they also have some unavoidable defects that limit their application range

[0004] Cr 3+ :BeAl 2 o 4 The main disadvantages of (Alexandrite) crystals are: the tuning range is between 700 and 800nm, and the emission cross section is small (6×10 -21 cm 2 ), the required pumping threshold is high, and it also has the disadvantages of high damage rate and high thermal lens effect. In addition, because BeO is highly toxic, it also brings great difficulties to growth.

[0005] Ti 3+ :Al 2 o 3 The main disadvantage of the crystal is: the Ti in the crystal 3+ - Ti 4+ The appearance of ion pairs causes absorption in the laser output band, that is, the near-infrared band, which affects its laser performance, and because of its short lifetime of the upper energy level of the laser (only 3.2μs), it is necessary to use short pulse lasers, Q-switched lasers, continuous Pumping with a wave laser or a flash lamp that produces particularly short pulses further limits its applications.

However, there are also problems such as small absorption coefficient and low laser efficiency of LD pumping.