We report on GaSb-based 2.Xμm diode lasers with an improved waveguide design, leading to a reduced beam divergence in the fast axis of 44° full width at half maximum (FWHM), compared to 67° FWHM of a conventional broadened waveguide design. 2.3μm ridge-waveguide lasers with the improved epitaxial design showed, besides the narrow beam profile in the fast axis, an excellent slow axis beam quality [M2<1.1 up to 70mW, continuous wave (cw)]. 2.0μm broad-area lasers with the improved waveguide too, exhibit a maximum cw-output power of 1.96W.

No abstract

No abstract

No abstract

A novel optoelectronic receiver chip for a data rate of 2.5Gbit/s has been developed and tested. It integrates a metal- semiconductor-metal photodiode with a GaAs HEMT transimpedance amplifier, a high gain amplifier and a limiting output buffer which is able to drive a 50 Ohm load. A special feature of the chip is that it comprises a very large photodiode of 300 mu m diameter, eliminating the need for expensive fibre alignment. Measurements reveal that the receiver achieves the required sensitivity of -15.7dBm at a bit error rate of 10(exp -9)