OPTICAL AMPLIFIERS PROVIDING HIGH PEAK POWERS WITH HIGH ENERGY LEVELS

摘要

Two approaches are provided for achieving an optical amplifier system capable of producing high peak power, high energy pulse outputs while suppressing scattering noise. The first approach relates to an optical amplifier system which has at least one laser diode pulsed or cw pumped double clad fiber amplifier utilized for receiving a high frequency modulated injected signal pulse of short duration from the laser diode, via the fiber core, for amplification by coupling pump light into the inner cladding of the fiber. The average signal power is sufficient to saturate the gain of the fiber so as to minimize significant onset and buildup of forward and backward scattering noise. The duty cycle of the injected signal source pulse is chosen to allow adequate gain recovery in the fiber amplifier between pulses. The second approach relates to a cascaded optical amplifier system having at least two optical amplifying stages with two pulsed pump sources provided and two amplifying media, the first of which receives the injection and at least one pump signal wherein the injection pulsed signal is amplified to a first power and energy level. The second amplifying medium, optically coupled to the first, amplifies the first level signal to a second level amplified, injection pulsed signal. The duty cycle of the injection pulsed optical signal is synchronized with the first and second pulsed pump signals with the first pulsed pump signal having a different duration in the duty cycle than the second pulsed pump signal.