Generation of high-power pulses in the GHz range with three-section DBR lasers

Ridge waveguide distributed Bragg reflector (RW-DBR) lasers having an active gain section and passive phase shift and Bragg sections were used to generate high power optical pulses with small spectral widths and repetition rates in the GHz range at an emission wavelength of 1060nm. The Ohmic p-contacts of the passive sections were deposited on the ridge as small metal stripes with a resistance per length of about 10 Omega/mm. If an electrical current flows along the stripes, a selective heating and hence a controllable increase of the absorption can be achieved. If the absorption is strong enough, even for large currents injected into the gain section no lasing can be observed. With small current pulses through the absorbing region Q-switched ps-pulses with high peak power of 1W can be generated. Theoretical investigations based on the solution of the time-dependent travelling-wave equations and carrier density rate equation yield a good agreement with experimental results.