Hybrid and monolithic integrated optic/millimeter-wave converters for 60 GHz radio-over-fiber systems
Hybrid as well as monolithic integrated /spl lambda/=1.55 /spl mu/m optic/millimeter-wave converters were developed and investigated experimentally based on detailed microwave simulations. Both converters working near 60 GHz showed responsitivities of about 1 A/W in good agreement with the simulations.
Reactive matching of millimetre-wave photodetectors using coplanar waveguide technology
The design, fabrication, and characterisation of a monolithically integrated narrowband photoreceiver on InP for 38 GHz operation is reported. The device comprises an ultrafast sub-half-micrometre InGaAs metal-semiconductor-metal photodetector and a reactive matching network based on coplanar waveguides. Compared to a purely resistive match, a 4 dB increase in the power transfer between the detector and the 50 Ω load is achieved.
Coherent pulsed injection seeding of two gain-switched semiconductor lasers
High-power, narrow-spectrum, short pulses at a wavelength near 830 nm are needed for optical logic applications. The authors report the generation of two coherent trains of pulses by pulsed injection seeding of two gain-switched semiconductor lasers with one mode-locked master oscillator. The available power was doubled and both lasers emit in nearly identical spectral lines. Short pulses (30-50 ps) are generated at a repetition rate of 1.9 GHz. The spectrum is reduced to a single mode cluster and shows a 1.7 AA wide chirp suitable for pulse compression. The peak power is 0.1 W for each pulse train. The capability of this technique for coherent power combining is demonstrated.<<ETX>>