Frequency tuning of a Stokes wave for stimulated four-photon mixing by temperature-induced birefringence change

Frequency tuning of a Stokes wave for stimulated four-photon mixing in an elliptical-core fiber is achieved by changing the magnitude of the stress-induced birefringence that is due to the relaxation of residual stress controlled by temperature. As the birefringence is decreased by heating the fiber to 700 degrees C, the frequency shift of the Stokes wave is decreased by about 80 cm(-1) for a pump wavelength of 1.064 microm. This result is in agreement with the theoretical prediction.