Active Q-switching in an erbium-doped fiber laser using an ultrafast silicon-based variable optical attenuator

Abstract

Presented herein is the use of an ultrafast Si-based variable optical attenuator (VOA) as a Q-switch for rare earth-doped fiber lasers. The ultrafast VOA is based on a forward-biased p-i-n diode integrated with a ridge waveguide, which was originally designed and optimized for WDM channel power equalization in optical communication systems. By incorporating a Si-based VOA with a transient time of similar to 410 ns into an erbium-doped fiber-based Fabry-Perot cavity it has been shown that stable Q-switched pulses possessing a temporal width of less than similar to 86 ns can be readily obtained at a repetition rate of up to similar to 1 MHz. The laser's peak power of similar to 38 W is shown to be obtainable at 20 kHz with a slope efficiency of similar to 21%. (C) 2011 Optical Society of America