Kumio KASAHARA, Koichiro NAKAMURA, Manabu SATO and Hiromasa ITO

Research Institute of Electrical Communication, Tohoku University, Sendai, 980-77 Japan

(Received June 6, 1996; Accepted November 7, 1996)

A frequency-shifted feedback (FSF) laser has multi frequency components with simultaneous linear chirping in its oscillation spectrum even though the gain medium is homogeneously broadened. The spectral intensity and its bandwidth were analyzed by the proposed spectral dynamics model based on the regenerative amplification of the continuously chirped comb components with phase shift according to each round trip in the cavity. The spectral intensity peaks at an instantaneous frequency which depends on the net gain in the cavity and the gain bandwidth of atomic transition. The oscillation bandwidth is defined as the product of the saturation-broadened bandwidth and the total resonant modes contributing to the FSF operation.

Key words : frequency-shifted feedback, acousto-optic modulator, all solid-state laser, spectral dynamics, oscillation bandwidth, instantaneous frequency