Picosecond pulse generation in CW semiconductor lasers using a novel regenerative gain-switching technique

The authors demonstrate a technique for regeneratively gain-switching semiconductor laser diodes to generate picosecond pulses with tunable repetition rates. The technique is applied to several semiconductor laser diodes, and pulse widths of the order of 35 ps and tuning of the repetition rate from approximately 200-500 MHz were obtained in preliminary experiments. With further refinements, such as the use of higher bandwidth diode lasers (including surface emitting lasers), special saturable absorbers (e.g. a dual segment laser with one segment biased below transparency) and broadband RF harmonic generators (including step recovery diodes, nonlinear transmission lines, and pulse forming networks), pulse widths as short as approximately 10 ps are anticipated.>