Title :
Novel delayed pulse techniques for stimulated Raman scattering
Author :
Marshall, Larry R. ; Piper, James A.
Author_Institution :
Fibertek Inc., Herndon, VA, USA
fDate :
2/1/1993 12:00:00 AM
Abstract :
The outputs of two independent, incoherent lasers are spatially overlapped in a Raman-active medium. When the probes are separated in time, the stimulated Raman scattering (SRS) efficiency of the delayed pulse is increased from 14 to 27%. This occurs because of the presence of the decaying coherent excitation induced by the SRS of the first pulse. The influence of saturable losses is removed by prepulsing the medium before applying the pulse pair. The temporal evolution of the enhancement and phase-matching conditions are investigated. Surprisingly, the pulses interact only when they are separated in time, with the enhancement vanishing when they are temporally overlapped. The outputs of several independent lasers may be combined to generate significantly higher SRS efficiencies, without increasing the pump intensity incident on the medium. The technique provides a means for recovering efficient SRS in the transient (short-pulse) regime
Keywords :
optical losses; optical saturation; stimulated Raman scattering; 14 to 27 percent; Raman-active medium; SRS efficiency; decaying coherent excitation; delayed pulse techniques; incoherent lasers; phase-matching conditions; pulse pair; pump intensity; saturable losses; short pulse regime; stimulated Raman scattering; temporal evolution; transient regime; Absorption; Delay effects; Frequency conversion; Laser excitation; Laser mode locking; Optical pulse generation; Pump lasers; Raman scattering; Temperature; Transient response;
Journal_Title :
Quantum Electronics, IEEE Journal of
