ThermoPix: A High-Spatial-Resolution ElectronicPhotonic Temperature Sensor Array With Microsecond Row Readout
2026-06-03 • Emerging Technologies
Emerging Technologies
AI summaryⓘ
The authors present ThermoPix, a system that measures temperature using light and electronics together on the same chip. They use a special photonic sensor that changes its light pattern with temperature, and convert these changes into electrical timing signals that CMOS circuits can read. Their design is energy-efficient and works without needing extra cooling. They also explore ways to share optical power across many sensors for large arrays. Overall, their work offers a scalable way to build detailed temperature sensor grids using combined photonic and electronic technology.
CMOS circuitryPhotonic interferometerValley photonic crystal Mach-Zehnder interferometer (VPCMZI)Wavelength shiftPhotodetectorPhase-transition-material deviceTiming-based readoutPower-delay product (PDP)Optical power distributionPhotonic-electronic integration
Authors
Md Rahatul Islam Udoy, Dharanidhar Dang, Wantong Li, Sumeet Kumar Gupta, Suman Datta, Ahmedullah Aziz
Abstract
This paper presents ThermoPix, a CMOS-compatible electronic-photonic architecture for high-spatial-resolution temperature sensing. The proposed system converts temperature-induced wavelength shifts in a photonic interferometric sensor into timing information that can be processed by CMOS circuitry. We use a valley photonic crystal Mach-Zehnder interferometer (VPCMZI) as the sensing element, whose temperature-dependent spectral response is detected using an integrated waveguide photodetector and translated into a time-varying photocurrent. A CMOS readout circuit employing a phase-transition-material device performs threshold detection and generates a timing signal corresponding to the temperature-dependent crossing event. Circuit-level simulations demonstrate a temperature sensitivity of 3.15 ns/K, a row readout time of 2 us, and a sensing power-delay product (PDP) of 0.152 fJ. The required optical power per photonic cell is 150 nW, enabling energy-efficient array operation without requiring cooling or special environmental arrangements. We also present alternative photonic layer architectures for optical power distribution across the array. In one approach, we use different tap ratios along the row, while the other uses identical tap ratios with bidirectional excitation. The resulting average photonic cell pitches are 23.26 um and 38.52 um, respectively. The proposed ThermoPix architecture therefore provides a scalable platform for integrated temperature sensing arrays that combine photonic sensing elements with CMOS-compatible timing-based readout.