Integrated photodetectors for compact Fourier-transform waveguide spectrometers

Area of Science:

• Optoelectronics
• Spectroscopy
• Nanotechnology

Background:

• Miniaturizing infrared spectrometers for consumer electronics and satellites faces challenges with spectral bandwidth and resolution.
• Existing Fourier-transform spectrometers offer high performance but lack miniaturization.
• Waveguide-based Fourier-transform spectrometers reduce footprint but require external sensors.

Purpose of the Study:

• To demonstrate a proof-of-concept miniaturized Fourier-transform waveguide spectrometer.
• To integrate a novel photodetector for a compact and efficient design.
• To overcome the limitations of current miniaturized spectrometer technologies.

Main Methods:

• Developed a waveguide-based Fourier-transform spectrometer.
• Incorporated a subwavelength, complementary-metal-oxide-semiconductor-compatible colloidal quantum dot photodetector.
• Fabricated an ultracompact spectrometer with a total active volume below 100 μm × 100 μm × 100 μm.

Main Results:

• Achieved a large spectral bandwidth with moderate spectral resolution (50 cm⁻¹).
• Demonstrated a functional miniaturized Fourier-transform spectrometer.
• Validated the performance of the integrated colloidal quantum dot photodetector.

Conclusions:

• The ultracompact spectrometer design is suitable for integration into consumer electronics and space devices.
• This technology overcomes the trade-off between bandwidth and resolution in miniaturized infrared spectrometers.
• Enables advanced optical/analytical measurements in portable and space-constrained applications.