A continuous-wave dye laser having a self-pumped phase conjugator in place of its usual output mirror will slowly change its own output wavelength with time. The laser has a bandwidth of 1.5 GHz and can self-scan to either longer or shorter wavelengths over a 37-nm range. The phase conjugator uses self-pumped four-wave mixing in a BaTiO3 crystal. A ring laser that uses two-wave mixing in the same crystal is also observed to have a frequency offset of a few hertz compared with the frequency of the pumping beam. These two effects are related; both are caused by a spontaneously moving photorefractive-index grating in the BaTiO3 crystal.
© 1984 Optical Society of AmericaFull Article | PDF Article