A novel monolithically integrated Michelson interferometer using intersecting twin-contact semiconductor optical amplifiers is proposed and implemented whereby the two arms are gain imbalanced to give enhanced noise suppression. Experimental OSNR improvements of 8.4 dB for pulses with durations 8 ps and by default ER of 14 dB are demonstrated for low driving currents of between 25 and 30 mA. This is believed to be the smallest Michelson interferometer to date.
Moll, E., Chai, Y. J., Williams, K. A., Penty, R. V., & White, I. H. (2006). Noise suppression in monolithically integrated Michelson interferometer. Electronics Letters, 42(3), 176-178. https://doi.org/10.1049/el:20064115