[K-8] Innovative Devices and Systems for Advanced Imaging and Sensing

[K-8-03] Double Modulation Lock-in Based Stimulated Raman Scattering Detection Method Using a Charge Modulator CMOS Image Sensor

〇Shukri Bin Korakkottil Kunhi Mohd¹, De Xing Lioe², Keita Yasutomi³, Keiichiro Kagawa⁴, Mamoru Hashimoto⁵, Shoji Kawahito⁶ (1. Shizuoka University (Japan), 2. Shizuoka University (Japan), 3. Shizuoka University (Japan), 4. Shizuoka University (Japan), 5. Hokkaido University (Japan), 6. Shizuoka University (Japan))

Presentation style: Online

https://doi.org/10.7567/SSDM.2022.K-8-03

This paper reports a design of the Stimulated Raman Scattering (SRS) detection method using a high-speed lock-in CMOS image sensor. Since the SRS signal is very weak, a two-stage fully-differential switched-capacitor integrator is designed to cancel offset light and amplify the SRS signal. The sensitivity of the proposed method is shown based on the relative intensity of up to ΔISRS / Ioffset = 10-6. The two-stage readout mechanism reduces the circuit's low-frequency noise by approximately 1-decade, which improves the dynamic range. The advantage of the double-modulation technique is that the system's low-frequency noise is reduced, where the first modulation is for laser intensity noise and the second is for circuit noise.