We have measured a propagation length L of TM0 and TE0 guided waves in a lossy Si film surrounded by identical dielectrics 632.8 nm in wavelength. The propagation length L(E)ATR estimated from experimental attenuated total reflection (ATR) spectra deviated largely from the propagation length L(T)ATR estimated from calculated ATR spectra in the range of small optical thickness of Si film hopt. This discrepancy may arise from an angular beam spread of incident light. We have proposed a method to measure L directly. This method gave us an L for TM0 guided waves of 1.6 mm at hopt = 6.1 nm. This value is in good agreement with L(T) ATR when L(E)ATR = 0.2 mm, under certain conditions.
© 1995 Optical Society of America
Masakazu Takabayashi, Masanobu Haraguchi, and Masuo Fukui, "Propagation length of guided waves in lossy Si film sandwiched by identical dielectrics," J. Opt. Soc. Am. B 12, 2406-2411 (1995)