[19a-438-1~12] 3.8 Optical measurement, instrumentation, and sensor

[19a-438-8] Cancellation of Phase Noise Induced by Light Source Intensity Noise in Pulse Repetition Phase Detection Technique for Intensity Noise Cancellation

〇Keisuke Seto¹, Takayoshi Kobayashi^1,2, Eiji Tokunaga¹ (1.Tokyo Univ. Sci., 2.Univ. Electro-Commun.)

Keywords:Noise cancel, pump/probe measurement, spectroscopy

In pump/probe measurement, intensity noise of the probe light source deteriorates signal-to-noise-ratio (S/N). We have developed a method to improve the S/N with a pulse-repetition-phase detection technique. In this method, we converted the intensity change of the probe light induced by a sample into the pulse repetition phase independently of the intensity noise. However, intensity noise is partially converted into phase noise, and this effect limits the performance. We demonstrate a technique to cancel the phase noise caused by the intensity noise.