Silicon Photonic Circuitry Research Articles

AlGaAs Bragg reflection waveguides for hybrid quantum photonic devices

Hybrid photonic devices represent a promising solution to the effective on-chip integration of all the components required for the generation, manipulation and detection of non-classical states of light encoding quantum information. We present an AlGaAs source of highly entangled photon pairs envisioned for the hybridization with silicon-on-insulator integrated platforms, in order to take benefit from the strong second order nonlinearity and the compliance with electrical pumping of the III-V platform and the maturity and CMOS compatibility of silicon photonic circuitry, enabling a wide variety of quantum information applications.

Chip-to-chip quantum teleportation and multi-photon entanglement in silicon

Integrated optics provides a versatile platform for quantum information processing and transceiving with photons1–8. The implementation of quantum protocols requires the capability to generate multiple high-quality single photons and process photons with multiple high-fidelity operators9–11. However, previous experimental demonstrations were faced by major challenges in realizing sufficiently high-quality multi-photon sources and multi-qubit operators in a single integrated system4–8, and fully chip-based implementations of multi-qubit quantum tasks remain a significant challenge1–3. Here, we report the demonstration of chip-to-chip quantum teleportation and genuine multipartite entanglement, the core functionalities in quantum technologies, on silicon-photonic circuitry. Four single photons with high purity and indistinguishablity are produced in an array of microresonator sources, without requiring any spectral filtering. Up to four qubits are processed in a reprogrammable linear-optic quantum circuit that facilitates Bell projection and fusion operation. The generation, processing, transceiving and measurement of multi-photon multi-qubit states are all achieved in micrometre-scale silicon chips, fabricated by the complementary metal–oxide–semiconductor process. Our work lays the groundwork for large-scale integrated photonic quantum technologies for communications and computations. Four single-photon states are generated and entangled on a single micrometre-scale silicon chip, and provide the basis for the demonstration of chip-to-chip quantum teleportation.

High power GaInNAs superluminescent diodes emitting over 400 mW in the 1.2 μm wavelength range

A high-power superluminescent diode emitting over 400 mW in the 1.2 μm range is reported. The active region is based on a single GaInNAs/GaAs quantum well positioned within a low-confinement vertical waveguide and a lateral ridge waveguide geometry, ensuring single transverse mode operation. The peak wall-plug efficiency and the differential efficiency in the linear region were 22.8% and 0.38 W/A, respectively. The full width at half-maximum spectral width for the maximum output power was 22 nm, corresponding to a spectral power density of 19 mW/nm, a threefold increase compared to continuous wave superluminescent diodes based on a quantum dot active region operating in the same wavelength range. Besides exhibiting excellent optical and electrical properties, the GaInNAs active region enhances operation at elevated temperatures. In this respect, an output power of about 210 mW is demonstrated at operation temperatures as high as 60 °C, while 150 mW is still emitted at 70 °C. The unique combination of parameters demonstrated makes these GaInNAs QW-based superluminescent diodes particularly attractive for hybrid integration with silicon photonic circuitry, enabling the demonstration of compact solutions for sensing, optical coherence tomography, and other emerging concepts exploiting photonic integration technology and requiring single transversal mode operation, good efficiency, broadband high spectral power density, and uncooled operation at elevated temperatures.

Non‐Volatile Silicon Photonics Using Nanoscale Flash Memory Technology

AbstractNonvolatile flash memory technology is widely used in our daily life. Following the recent progress in silicon photonics, there is now an opportunity to embed flash memories also in photonic applications. As of today, chip scale photonic devices, e.g., micro‐resonators, are becoming essential building blocks in modern silicon photonics. However, their properties, such as their resonance frequencies, fluctuate due to fabrication tolerances, significantly limiting their applicability. Here, by integrating the well‐established non‐volatile flash memory technology into silicon photonic circuitry, this major obstacle is tackled and electrical post trimming of such resonators is demonstrated. Specifically, the Metal‐Oxide‐Nitride‐Oxide‐Silicon (MONOS) structure is used to trap charges in the thin silicon nitride layer, located in close proximity to the silicon device layer. This enables accumulating charges in the silicon, modifying the effective index of the optical mode and consequently the resonance frequency. By doing so, a robust and CMOS compatible nonvolatile memory solution is provided, which not only allows for precise trimming of the resonance frequency of the photonic device, but can also be easily manufactured and commercialized. This approach paves the way for efficient utilization of photonic structures such as resonators and interferometers in chip scale silicon photonics and electro optic systems, with a wide range of applications spanning from filters, switches and modulators, to sensors, and even lasers.