Optimisation of 10 Gbit/s InGaAsP electroabsorption modulator operating at high temperature

The authors present the development of an electroabsorption modulator (EAM) based on the quantum confined Stark effect in InGaAsP strained multiple quantum wells (MQWs), suitable for 40-80 km propagation of 10 Gbit/s optical signals on standard single-mode fibre at 1.55 mum. A microscopic model has been developed to calculate the EAM optical properties as a function of the electric field and temperature, starting from the composition and thickness of the strained MQW layers. An MQW structure has been designed and fabricated to obtain high extinction ratio, low insertion loss and negative chirp at 1.55 mum and 60degreesC. Experimental results on discrete EAMs are reported and compared with the model. The devices demonstrate a contrast ratio of >10 dB, an insertion loss of 5 dB and a negative chirp at 10 Gbit/s, 60degreesC, with a 2 V voltage swing.