Coupling Silicon defect centers to photonic structures

Coupling defect centers in silicon to novel photonic structures can significantly enhance their photon collection efficiency and radiative rate, making them a suitable candidate for an efficient and indistinguishable single-photon source. Recent studies have demonstrated spin-defect centers in silicon as a viable photon-spin interface due to the long spin lifetime, emission in the telecommunication O-band and CMOS-compatible host material. Single photon emission from many families of radiation damage centers, namely G centers, W centers, T centers, and so on, have been shown to give stable near-IR emission at low temperatures. However, many of the fundamental photophysical properties of these emitters remain unknown or only partially known, including their long-term stability, sensitivity to their environment, carrier dynamics, and linewidths. Moreover, there is not enough evidence on how to effectively and reproducibly generate these defects, and their incorporation into photonic and electronic structures is virtually unexplored. In this talk, we will present the results of our investigation on the G center synthesis and some optical characterization techniques we have employed to determine their saturation power, lifetime, linewidths, etc. Additionally, we look into incorporating G centers into circular grating couplers, also known as Bull's eye structures, to quantify the enhanced photon emission rate and the photon extraction efficiency of the emitters embedded in the central circular region.