High quality-factor Si/SiO 2 -InP hybrid micropillar cavities with submicrometer diameter for 1.55-μm telecommunication band

We theoretically demonstrate high quality(Q)-factor micropillar cavities at 1.55-μm wavelength based on Si/SiO2-InP hybrid structure. An adiabatic design in distributed Bragg reflectors (DBRs) improves Q-factor for upto 3 orders of magnitude, while reducing the diameter to sub-micrometer. A moderate Q-factor of ~3000 and a Purcell factor of ~200 are realized by only 2 taper segments and fewer conventional DBR pairs, enabling single photon generation at GHz rate. As the taper segment number is increased, Q-factor can be boosted to ~105-106, enabling coherent exchange between the emitter and the optical mode at 1.55 μm, which is applicable in quantum information networks.