On-chip spectrometers using stratified waveguide filters.

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Spectroscopy

Background:

• Traditional spectrometers are often bulky and complex.
• The demand for miniaturized optical sensing solutions is growing across various industries.
• Silicon photonics offers a promising platform for on-chip optical devices.

Purpose of the Study:

• To present an ultra-compact, single-shot spectrometer on a silicon platform.
• To demonstrate its capability for sparse spectrum reconstruction.
• To achieve the smallest footprint spectrometer on silicon to date.

Main Methods:

• Utilizing 32 stratified waveguide filters (SWFs) with diverse transmission spectra.
• Designing an ultra-compact 1x32 splitter for low power imbalance.
• Fabricating the device on a silicon photonic platform.

Main Results:

• Achieved an unprecedented footprint of approximately 35µm x 260µm.
• Demonstrated a broad operating bandwidth of 180 nm centered at 1550 nm.
• Resolved narrowband peaks with 0.45 nm Full-Width-Half-Maximum (FWHM).

Conclusions:

• The developed spectrometer is the smallest realized on a silicon photonic platform.
• This technology enables high-resolution spectral analysis in a compact form factor.
• The concept is adaptable to other material platforms for diverse spectral applications.