Transient analysis of an electronically tunable dye laser - Part I: Simulation study

Computer simulation results of a dye laser electronically tuned by an acoustooptic filter in the laser cavity are presented. The filter employs a nonlinear anisotropic crystal in which a colinear acoustic beam diffracts the light into the orthogonal polarization. Only a narrow wavelength band is constructively diffracted and since the band center is determined by the acoustic frequency, it is easily controlled electronically. The filter causes the frequency of the light to shift by twice the acoustic frequency in a round trip and so the usual laser resonance condition is not satisfied. The simulation indicates that the previously predicted steady-state results are attained under CW pumping conditions. With a representative CaMoO
4
fillter, approximately 3 μs are required to achieve the steady state and a 0.3 Å spectral bandwidth is typical. Similarly a LiNbO
3
filter requires 150 ns and produces a 0.17-Å spectral bandwidth. Results of simulation studies for pulsed operation are also included.