Novel 10- to 40-GHz Telecom Pulse Generating Sources with High Average Power

摘要

With the motivation of telecom applications, we have introduced various novel multi-GHz sources, all based on diode-pumped, passively mode-locked solid-state lasers. The application of a semiconductor saturable absorber mirror in combination with optimized cavity designs allowed progression in performance regimes where these lasers become interesting for telecom applications. They have outstanding pulse properties and due to the fact that they are pulsed all passively, they present a simple and cheap way to produce a pulse train which can be synchronized to a clock signal. A simple approach appears to be the diode-pumped fundamental mode-locked Er:Yb:glass laser generating high-quality picosecond pulses at multi-GHz repetition rates with pulse parameters variable in a wide range. Pulse durations between 1 ps and 19 ps and pulse repetition rates of 10, 25, and 40 GHz enable OTDM and DWDM applications. C-band tunability of the 10 and 25 GHz lasers have been demonstrated. Higher repetition rates, higher powers, and shorter pulses for higher bit rates appear to be feasible. For an even wider tuning range including S-, C-, and L-band, an optical parametric oscillator, synchronously pumped by a high-power high-repetition-rate Nd:YVO_4 laser can be applied. It also yields significantly higher average powers. So far, up to 120 mW average output power and up to 108 nm tuning range in the 1.5-μm region have been achieved with 10-GHz OPOs, but even higher power levels, higher pulse repetition rates and wider tuning ranges seem to be possible.