Wide-range and ultra-low temperature thermometer based on a silicon resonator

Area of Science:

• Photonics
• Cryogenic Engineering
• Materials Science

Background:

• Optical sensors face challenges in acquiring signals at cryogenic temperatures.
• Silicon microring resonators (MRRs) offer potential for on-chip sensing due to CMOS compatibility and high-quality factors.

Purpose of the Study:

• To experimentally demonstrate silicon-based microring resonators for cryogenic temperature sensing.
• To investigate the performance and sensitivity of MRRs across a wide temperature range, down to 10 K.

Main Methods:

• Experimental demonstration of silicon microring resonators.
• Measurement of optical signal acquisition at cryogenic temperatures.
• Characterization of sensor sensitivity from 240 K down to 10 K.

Main Results:

• A wide-range cryogenic temperature sensor (240 K to 10 K) was successfully demonstrated.
• Device sensitivity decreased from 64.7 pm/K at 240 K to 4.19 pm/K at 10 K.
• Experimental results align with theoretical analysis of weakening thermo-optic effects at lower temperatures.

Conclusions:

• Silicon-based microring resonators are a viable platform for ultra-low temperature monitoring.
• The CMOS-compatible nature and chip-scale integration capabilities of MRRs are advantageous for cryogenic sensing applications.
• Further research can optimize MRR design for enhanced sensitivity at extremely low temperatures.