Ruby ring laser subjected to an external signal

A superregenerative amplification scheme was used to obtain unidirectional stimulated emission from a ruby ring laser under free-oscillation and Q -switched conditions. The duration of external control pulses was either t_c > L/c or t_c < L/c. The carrier frequency of giant pulses could be tuned within a range of 0.25 nm when the spectrum was 6×10^–5 nm wide. Reproducible generation of short high-coherence light pulses was achieved.