Distributed temperature sensing on silicon-on-insulator chip by optical frequency domain reflectometry

Area of Science:

• Photonics
• Materials Science
• Integrated Optics

Background:

• Traditional on-chip temperature sensors often require complex, dedicated structures.
• Existing methods typically rely on transmission spectrum analysis, limiting design flexibility.
• Accurate, high-resolution temperature monitoring is crucial for advanced integrated circuit performance.

Purpose of the Study:

• To introduce a novel distributed temperature sensing (DTS) technique for silicon-on-insulator (SOI) chips.
• To demonstrate a sensing method that utilizes inherent waveguide properties, avoiding specialized structures.
• To enable precise measurement of temperature distributions and thermal crosstalk on-chip.

Main Methods:

• Implementation of optical frequency domain reflectometry (OFDR) on SOI chips.
• Utilizing Rayleigh backscatter from as-fabricated waveguide sidewall roughness for sensing.
• Characterizing sensor performance including spatial resolution and temperature sensitivity.

Main Results:

• Achieved a sensing spatial resolution of 200 μm.
• Demonstrated high temperature sensitivity of 88 pm/K.
• Successfully measured non-uniform temperature distributions on SOI waveguides using integrated heaters.

Conclusions:

• The novel DTS technique offers a straightforward sensing structure on SOI chips.
• This method eliminates the need for specially designed temperature sensing elements.
• Opens new avenues for on-chip thermal analysis and crosstalk investigation.