Mach-Zehnder optical modulator using polariton propagation

We developed a Mach-Zehnder optical modulator based on propagation of a polariton, which is a composite quasi-particle formed by the coupling of an exciton and a photon. The modulation characteristics, measured at liquid-He temperature, showed an operation voltage of 0.7 V, which is extremely low in comparison with a conventional device. The corresponding extinction ratio was 11 dB. We also demonstrated the wavelength dependence of the modulation characteristics. These results suggest the possibility of developing high-performance polariton optical devices.