Title :
Doubly Passively Self-Q-Switched Cr4+:Nd3+:YAG Laser With a GaAs Output Coupler in a Short Cavity
Author :
Yang, Kejian ; Zhao, Shengzhi ; Li, Guiqiu ; Li, Dechun ; Wang, Jing ; An, Jing ; Li, Ming
Author_Institution :
Sch. of Inf. Sci. & Eng., Shandong Univ.
Abstract :
By using a GaAs as both an output coupler and a saturable absorber, we present a doubly passively self-Q-switched Cr4+:Nd3+:YAG laser in a short cavity for the first time to our knowledge. This laser can generate more symmetric pulse shape and shorter pulsewidth in comparison with the solely self-Q-switched Cr4+:Nd3+:YAG laser. The output pulse energy and peak powers are higher than those in our previous doubly passively Q-switched lasers. By considering the Gaussian spatial distribution of the intra-cavity photon density and the free carrier absorption (FCA) in GaAs wafer, a set of modified rate equations have been introduced to describe the performances of the doubly Q-switched Cr 4+:Nd3+:YAG laser with GaAs coupler. The numerical solutions of the equations and the experimental results are found to agree with each other very well. The effect of FCA process in GaAs wafer has been discussed and proved to play an important role in the pulse compression and symmetry
Keywords :
III-V semiconductors; Q-switching; chromium; gallium arsenide; laser cavity resonators; neodymium; optical couplers; optical pulse compression; optical pulse generation; optical saturable absorption; solid lasers; Cr4+:Nd3+:YAG laser; GaAs; GaAs output coupler; GaAs wafer; Gaussian spatial distribution; YAG:Cr,Nd; YAl5O12:Cr,Nd; doubly passive self-Q-switching; free carrier absorption; intracavity photon density; modified rate equations; optical pulse compression; optical pulse symmetry; saturable absorber; short laser cavity; symmetric pulse shape generation; Chromium; Equations; Gallium arsenide; Neodymium; Optical coupling; Optical pulse generation; Optical pulse shaping; Optical pulses; Shape; Space vector pulse width modulation; ${hbox {Cr}}^{4+}{hbox {:Nd}}^{3+}{hbox {:YAG}}$ crystal; doubly $Q$-switched; passively $Q$-switched; self-$Q$ -switched laser;
Journal_Title :
Quantum Electronics, IEEE Journal of
DOI :
10.1109/JQE.2006.886811
