Compact photonic crystal spectrometer with resolution beyond the fabrication precision

Area of Science:

• Photonics
• Spectroscopy
• Materials Science

Background:

• Spectrometers are crucial for analyzing light across various wavelengths.
• Silicon photonic crystals offer a platform for miniaturized optical devices.
• Achieving high wavelength resolution in compact devices remains a challenge.

Purpose of the Study:

• To design and demonstrate a compact silicon photonic crystal spectrometer.
• To achieve wavelength resolution exceeding 1.6 nm.
• To explore the role of random light localization in enhancing spectrometer performance.

Main Methods:

• Fabrication of a silicon photonic crystal device with a footprint of 740 × 9 µm².
• Characterization of wavelength resolution at single and multiple wavelength operations.
• Utilizing the phenomenon of random light localization.

Main Results:

• Achieved a device footprint of 740 × 9 µm².
• Demonstrated excellent wavelength resolution of ∼0.01 nm (single) and <0.03 nm (multiple).
• Exceeded the target resolution of 1.6 nm due to random light localization.

Conclusions:

• The compact silicon photonic crystal spectrometer demonstrates superior wavelength resolution.
• Random light localization is a key factor in achieving enhanced performance.
• This technology holds promise for advanced spectroscopic applications.