[22p-P03-1~8] 3.10 Photonic structures and phenomena (formerly 3.11)

▲ [22p-P03-2] Design of a Defect-Based Photonic Crystal Nanobeam Cavity on a Silicon Nitride Waveguide for Efficient Generation of Single Photon by Resonant Excitation

〇Natthajuks Pholsen^1,2, Yasutomo Ota³, Satoshi Iwamoto^1,2 (1.RCAST, UTokyo, 2.IIS, UTokyo, 3.Keio Univ.)

Keywords:Single-photon sources, Quantum dot, Silicon nitride integrated photonics

We report a cavity design for InAs/GaAs quantum-dot single-photon source that can be resonantly excited with low crosstalk and efficiently coupled to an underlying SiN wire waveguide buried in glass. The design employs a GaAs photonic crystal (PhC) nanobeam cavity embedding a large defect region. Finite-difference-time-domain (FDTD) simulations show crosstalk can be suppressed to the order of 10^-13, which would be sufficient for obtaining high-quality single photons.¹ In addtion, with a novel strategy of matching the effective index of a section of PhC mirror with that of the underlying waveguide, we achieve coupling efficiency of more than 90% despite a large difference in refractive index of GaAs and SiN.
[1] M. N. Makhonin, et al., Nano Lett. 14, 6997–7002 (2014).