III-V-on-Silicon Photonic Integrated Circuits for Spectroscopic Sensing in the 2-4 μm Wavelength Range

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Spectroscopy

Background:

• Silicon photonic integrated circuits (ICs) are crucial for developing miniature optical sensors.
• The 2-4 μm wavelength range is key for trace gas and bio-molecule detection.
• III-V-on-silicon technology offers a pathway for integrated light sources and detectors.

Purpose of the Study:

• To review recent advancements in III-V-on-silicon waveguide circuits for spectroscopic sensing.
• To showcase the integration of laser sources and photodetectors for fully integrated optical sensors.
• To present compact tunable lasers and high-performance spectrometers for enhanced sensing capabilities.

Main Methods:

• Heterogeneous integration of III-V laser sources and photodetectors on silicon photonic ICs.
• Development of a widely tunable external cavity laser utilizing silicon photonic ICs.
• Fabrication of high-performance silicon arrayed waveguide grating spectrometers.
• Implementation of an on-chip photothermal transducer using a suspended silicon-on-insulator microring resonator.

Main Results:

• Successful heterogeneous integration of 2.3 μm wavelength III-V laser sources and photodetectors.
• Demonstration of a compact 2 μm wavelength tunable external cavity laser.
• Presentation of high-performance silicon arrayed waveguide grating spectrometers.
• Development of a mid-infrared photothermal spectroscopy system using an on-chip photothermal transducer.

Conclusions:

• III-V-on-silicon waveguide circuits are enabling highly integrated and compact optical sensors.
• These advancements facilitate sensitive detection of trace gases and bio-molecules in the 2-4 μm range.
• The presented technologies pave the way for next-generation spectroscopic sensing platforms.