Photonic chip-based low-noise microwave oscillator

Nature · 2024 · 172 citations

• Computer Science
• Optoelectronics
• Optics

at 10 kHz offset-values that are unprecedented for an integrated photonic system. All photonic components can be heterogeneously integrated on a single chip, providing a significant advance for the application of photonics to high-precision navigation, communication and timing systems.

Photon-trapping-enhanced avalanche photodiodes for mid-infrared applications

Nature Photonics · 2023 · 104 citations

• Optoelectronics
• Optics
• Materials science

Abstract The fast development of mid-wave infrared photonics has increased the demand for high-performance photodetectors that operate in this spectral range. However, the signal-to-noise ratio, regarded as a primary figure of merit for mid-wave infrared detection, is strongly limited by the high dark current in narrow-bandgap materials. Therefore, conventional mid-wave infrared photodetectors such as HgCdTe require cryogenic temperatures to avoid excessively high dark current. To address this challenge, we report an avalanche photodiode design using photon-trapping structures to enhance the quantum efficiency and minimize the absorber thickness to suppress the dark current. The device exhibits high quantum efficiency and dark current density that is nearly three orders of magnitude lower than that of the state-of-the-art HgCdTe avalanche photodiodes and nearly two orders lower than that of previously reported AlInAsSb avalanche photodiodes that operate at 2 µm. Additionally, the bandwidth of these avalanche photodiodes reaches ~7 GHz, and the gain–bandwidth product is over 200 GHz; both are more than four times those of previously reported 2 µm avalanche photodiodes.

Low-noise high-temperature AlInAsSb/GaSb avalanche photodiodes for 2-μm applications

Nature Photonics · 2020 · 141 citations

• Computer Science
• Optoelectronics
• Materials science