Temperature dependence mitigation in stationary Fourier-transform on-chip spectrometers

Area of Science:

• Photonics and Spectrometry
• Integrated Optics
• Optical Engineering

Background:

• High-resolution spectrometers are sensitive to temperature variations due to large optical path length differences.
• Stringent thermal stabilization is required for accurate measurements, increasing system complexity and cost.
• On-chip spectrometers, particularly waveguide spatial heterodyne Fourier-transform types, face challenges with temperature stability.

Purpose of the Study:

• To present and experimentally validate two novel techniques for mitigating temperature drift effects in on-chip spectrometers.
• To overcome the limitations imposed by thermal sensitivity in high-resolution integrated photonic devices.
• To demonstrate the effectiveness of temperature-sensitive calibration and phase error correction in preserving spectral accuracy.

Main Methods:

• Fabrication of a spectrometer chip on a silicon-on-insulator platform, featuring 32 Mach-Zehnder interferometers.
• Implementation of optical path delays using microphotonic spirals with lengths up to 3.779 cm.
• Experimental application of temperature-sensitive calibration and phase error correction algorithms to counteract thermal drift.

Main Results:

• Demonstrated effective elimination of spectral degradation caused by temperature drift.
• Achieved a spectral resolution of 17 pm with the developed on-chip spectrometer.
• Validated the robustness of the proposed mitigation techniques in real-world operating conditions.

Conclusions:

• Temperature-sensitive calibration and phase error correction are effective strategies for mitigating thermal drift in waveguide spectrometers.
• These techniques enable high-resolution on-chip spectral measurements without the need for complex thermal stabilization.
• The presented methods enhance the practicality and reliability of integrated photonic spectrometers for various applications.