Mode coupled Semiconductor Laser with Feedback as an Optoelectronic Oscillator

For wireless communications, high-resolution short-range radar systems and especially clocks in optical communication networks, electrical signals of GHz values with two to three-digits are used more and more. The requirements for their usage as clocks yield enormous challenges, particularly for matching the bit rate of electrical and optical signals.

The invention presented here tackles this problem. For this purpose the source of the optical clock signal is a monolithic integrated mode coupled semiconductor laser. He consists of a gaining section, producing photons by sufficiently high applied voltages, which are getting absorbed in the absorption section and thus inducing an electron hole pair. Just after a short recovery period, new pairs can get induced and the electric resistor can therefore be modulated. A coupling of the amplification and the saturable absorption leads to the formation of pulses in the cavity. An optical feedback loop takes part of the radiation back into the laser. The comb-like laser pulses (urpulse) are affected by temporally jitter, which gets decisively reduced by the invention.