[14a-PB2-1~15] 3.4 Biomedical optics

△ [14a-PB2-15] Development of Pseudo-noise Multiplexing Technique for High-speed One-shot Multi-wavelength Photothermal Spectroscopy

〇Hiromu Yamada¹, Keisuke Seto¹, Takayoshi Kobayashi², Eiji Tokunaga¹ (1.Tokyo Univ. Sci, 2.Univ. Electrocommun)

Keywords:photothermal spectroscopy, pump-probe, non-label

The frequency division multiplexing of wavelengths of the white pump light in the photothermal microscopy, where wavelength components are discriminated by the modulation frequency, enables simultaneous multi-wavelength absorption spectroscopy with a spatial super-resolution. However, the gains of the thermal lens generation to the high-frequency components are diminished due to the limited response speed of the thermal lens. This situation causes unbalance in gains to the constituent frequency components and results in distortion of the absorption spectrum. In this study, we multiplexed the wavelength with pseudo-noise sequences to eliminate the distortion in the spectrum. The frequency bandwidth of the pseud-noise sequences are equalized, and the gains of the thermal lens generation to respective wavelength components are balanced.