Power insensitive surface normal electroabsorption modulators

Surface normal electroabsorption modulators (SNEAMs) have unique electro-optic modulation properties, however their behavior and performance at high light intensity is affected by thermal nonlinearities that take place in the modulator active volume. Here, we show a novel approach to make SNEAMs insensitive to optical power without the use of power-hungry heaters or feedback control systems. By passively compensating for the thermo-optic dependence of the SNEAM resonant cavity, we obtain an eight-fold reduction in the wavelength shift of the SNEAM response at 4 dBm of input power. Furthermore, we show no appreciable degradation in the SNEAM eye diagram at 25 Gbit/s when the input power is increased up to 2 dBm, that is about 4 times higher than in conventional SNEAMs.