High-speed optical sensor interrogator with a silicon-ring-resonator-based thermally tunable filter.

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• On-chip optical interrogators with silicon-ring-resonator-based thermally tunable filters (SRRTFs) are suitable for portable sensing.
• Conventional SRRTF interrogators have slow speeds (a few Hz), limiting real-time dynamic sensing.

Purpose of the Study:

• To develop a high-speed optical interrogation system exceeding 100 kHz using SRRTFs.
• To overcome the speed limitations of current SRRTF-based systems for dynamic parameter monitoring.

Main Methods:

• Utilized the nonlinear transient response of SRRTFs to square-wave input voltage for speed enhancement.
• Scanned the entire spectral range of the SRRTF twice within its thermal response cycle.
• Converted time-domain sensor signals to the spectrum domain using characterized time-dependent resonance wavelength shifts.

Main Results:

• Achieved a high-speed optical interrogation system operating at 100 kHz.
• Demonstrated high-speed interrogation of a fiber Bragg grating sensor.
• Successfully captured dynamic temperature changes at 200 Hz.

Conclusions:

• The developed SRRTF-based system significantly enhances optical interrogation speed.
• This advancement enables real-time monitoring of dynamic parameters in optical sensing applications.
• The technique is effective for interrogating fiber Bragg grating sensors under rapidly changing conditions.