[20a-P01-1~21] 3.7 Optical measurement, instrumentation, and sensor

[20a-P01-11] Experimental Study for High Dynamic Range Film Thickness Measurement Using Amplitude Modulated Wave Interference

〇(M1)Fuma Wakabayashi¹, Kotaro Kawai² (1.Osaka Univ., 2.Kobe City College of Tech.)

Keywords:

optical interference,thickness measurement,heterodyne interference

In this study, we propose a double-heterodyne interferometer that can measure film thickness from several nm to several mm by using an amplitude-modulated wave generated by coaxial heterodyne interference of two light waves with slightly different wavelengths. We have theoretically and numerically demonstrated that this method can measure film thickness from the intensity distribution of interference fringes caused by four-beam interference. Therefore, in this presentation, we will present the results of amplitude-modulated wave interference for experimental demonstration of the proposed method.