Ultra-low loss quantum photonic circuits integrated with single quantum emitters

Abstract

The scaling of many photonic quantum information processing systems is ultimately limited by the flux of quantum light throughout an integrated photonic circuit. Source brightness and waveguide loss set basic limits on the on-chip photon flux. While substantial progress has been made, separately, towards ultra-low loss chip-scale photonic circuits and high brightness single-photon sources, integration of these technologies has remained elusive. Here, we report the integration of a quantum emitter single-photon source with a wafer-scale, ultra-low loss silicon nitride photonic circuit. We demonstrate triggered and pure single-photon emission into a Si3N4 photonic circuit with ≈ 1 dB/m propagation loss at a wavelength of ≈ 930 nm. We also observe resonance fluorescence in the strong drive regime, showing promise towards coherent control of quantum emitters. These results are a step forward towards scaled chip-integrated photonic quantum information systems in which storing, time-demultiplexing or buffering of deterministically generated single-photons is critical.

High-Quality Amorphous Silicon Carbide for Hybrid Photonic Integration Deposited at a Low Temperature

“…In quantum photonic circuits, routing photons with low losses is a vital requirement, and to this end, over the past decade, material platforms such as LPCVD silicon nitride have been extensively optimized to reduce the losses. Recent works using thin-film SiN waveguides have enabled high-yield and wafer-scale fabrication with losses as low as 1 dB/m, , which is a fundamental requirement for two-photon interference on chip. , As a future outlook, we highlight in Figure a the use of 280 nm thick a-SiC in combination with low-loss waveguides based on silicon nitride thin films (40 nm) and lithium niobate, two promising platforms for integrated quantum photonics. In this scheme, delay lines and photonic routing can be done with low loss on SiN to later exploit the nonlinearity of a-SiC in wavelength conversion experiments and generation of entangled photon pairs.…”

Efficient Photonic Integration of Diamond Color Centers and Thin-Film Lithium Niobate

“…Here, we demonstrate efficient heterogeneous integration of a diamond nanobeam featuring incorporated SiV color centers with a TFLN platform using a mechanical pick-and-place approach. ,− By precisely placing double-tapered diamond nanobeams, we demonstrate the bridging of a gapped TFLN waveguide with a diamond-to-LN transmission efficiency of 92 ± 11% per facet at 737 nm, corresponding to the SiV ZPL wavelength, averaged across multiple measurements. We find an approximately 2-fold improvement in ZPL photon extraction via integrated TFLN collection channels compared with that via out-of-plane collection from the same device.…”

Silicon-based surface gratings for efficient fiber-chip and free-space beam coupling

“…Integrated photonics provides many waveguide platforms to realize dense photonic circuits, opening a route for scalable and inexpensive solutions to develop high-performance chip-scale passive and active devices [1][2][3][4]. Advanced photonic integrated circuits are thus promising technology for myriad of applications, ranging from optical communications [5], quantum sciences [6], or light detection and ranging [7,8]. However, integrated photonic waveguides have submicrometric dimensions, which are indeed much smaller than the size of standard single-mode optical fibers (SMF-28) [9].…”