Chromium doped molybdic acid aluminum potassium tunable laser crystal

Abstract

The invention discloses a tunable laser crystal blended chrome-molybdenum acid aluminium potassium crystal and preparing method, which is characterized by the following: adopting fused salt top seed crystal method; adopting 60-80at%K2Mo3O10 as fluxing agent; setting detemperature rate at 1-5 deg. c / day; setting revolution rate at 5-30 rotation per min; growing out Cr3+:KAl(MoO4)2 crystal with high quality and bigger size; belonging to trigonal crystal system; possessing P3ml(D3d3) space group structure with refractive index at 1.74. This crystal can be used as tunable laser crystal with tunable range at 700-950 nm, which can be used to spectrography, biological medicine and military domain.

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] The so-called tunable laser refers to such an effect: the active ions doped in the solid matrix are excited by laser or pump lamp to generate laser output, and the prism tuning method, F-P etalon tuning method, grating tuning method, filter Methods such as tuning method and distributed feedback system tuning method can obtain tunable laser output. [0003] In 1963, L.F.Johnson et al. 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 du...

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.