Superconducting nanowires enable the operation of outstanding single-photon detectors, which are required particularly for quantum information and weak-light measurement applications. However, the trade-off between detection speed and efficiency, which is related to the filling factors of superconducting nanowires, is still a challenge. Here, we propose a fast, efficient single-photon detector fabricated by integrating ultralow-filling-factor meandered superconducting nanowires atop a photonic crystal (PhC) resonator. This unique structure enables a fast photon response due to the low kinetic inductance of the short nanowires and ensures efficient photon absorption due to the resonant effect of the PhC structure. The proposed detector has a filling factor of only ∼12% while maintaining a high maximum absorption in our simulation of 90%. The fabricated device exhibits a maximum system detection efficiency of 60%, a maximum count rate of ∼80MHz, and a recovery time of only ∼12ns, which is three times faster than that of the conventional meandered structure at the same sensing diameter (18 μm). This work helps advance the movement toward high-efficiency, high-speed single-photon detectors and promotes their future application in quantum communication and imaging.

Bound states in the continuum (BICs) can make subwavelength dielectric resonators sustain low radiation leakage, paving a new way to minimize the device size, enhance photoluminescence, and even realize lasing. Here, we present a quasi-BIC-supporting GaAs nanodisk with embedded InAs quantum dots as a compact bright on-chip light source, which is realized by heterogeneous integration, avoiding complex multilayered construction and subsequent mismatch and defects. The emitters are grown inside the nanodisk to match the mode field distribution to form strong light–matter interaction. One fabricated sample demonstrates a photoluminescence peak sustaining a quality factor up to 68 enhanced by the quasi-BIC, and the emitting effect can be further promoted by improving the epilayer quality and optimizing the layer-transferring process in the fabrication. This work provides a promising solution to building an ultracompact optical source to be integrated on a silicon photonic chip for high-density integration.

An ultra-broadband and fabrication-tolerant silicon polarization rotator splitter is proposed in this Letter. Benefitting from the broadband and low-loss characteristics of the bi-level taper and counter-tapered coupler, the designed device has a simulated insertion loss and crosstalk of less than 0.2 and 15 dB in the waveband from 1290 to 1610 nm. These characteristics make it valuable in applications with large bandwidth requirements, such as full-grid Coarse wavelength division multiplexer (CWDM) and diplexer/triplexer fiber-to-the-home systems. The fabrication tolerance of the design is also analyzed, showing that the device performance is quite stable with normal manufacturing errors in silicon photonics foundries.