Properties of gain-levered InGaAs/InP quantum well lasers

The gain-lever effect in long wavelength MQW lasers is studied for the first time. One application for improved fibre-microwave systems is in the area of mobile communications. The authors have measured the enhancement in AM response and RIN of InGaAs/InP MQW lasers at frequencies relevant to mobile and cellular communications systems. An AM enhancement of 10dB is seen at a frequency of 900 MHz with only a small increase in RIN. This leads to an improvement in the signal-to-noise ratio at the same frequency of 7.5 dB. Calculations demonstrate the existence of a trade-off between reduced link loss and noise figure, and reduced intermodulation and increased intermodulation free dynamic range