1998 Volume 26 Issue 12 Pages 887-891
In a frequency-shifted feedback (FSF) laser, an intracavity light field is frequency-shifted beforebeingrecirculated through a gain medium. The FSF operation is obtained by placing an acousto-optic modulator inside the cavity and closing the cavity by the first order diffracted light of the modulator. The intracavity frequency shift prevents an evolution of a standing wave in the cavity and the laser output exhibits a very unique spectral feature. In this paper, the spectral output of the FSF laser is examined by use of a diode-pumped Nd: YVO4 as a gain medium. A theoretical treatment of the FSF behavior is also discussed. It is shown here that the FSF laser output has spectral output called “chirped frequency comb” with an ultrafast frequency chirp rate of several hundreds of PHz/s.
