Method for measuring small optical absorption coefficients with use of a Shack–Hartmann wave-front detector

Sanichiro Yoshida (1, 2) , David H. Reitze (3) , David B. Tanner (3) , Justin D. Mansell (4)

1 Southeastern Lousiana University
2 LIGO Livingston
3 UF - University of Florida [Gainesville]
4 Intellite Inc.

We present a method for measuring absorption at the 1x10^(-5) cm^(-1) level in high-quality opticalmaterials. Using a Shack–Hartmann wave-front detector, thermal lensing in these materials may bemeasured. Then, the absorption coefficient may be estimated by fitting the observed deformation to athermal lensing model based on the temperature dependences of the refractive index and the thermalexpansion coefficient. For a particular sample of fused silica, the absorption coefficient was determinedto be 1.8±0.4x10^(-5) cm^(-1). Obtaining this result requires a resolution in the optical path length betterthan ±0.1 nm.

Domaines: Physique [physics]

Sanichiro Yoshida, David H. Reitze, David B. Tanner, Justin D. Mansell. Method for measuring small optical absorption coefficients with use of a Shack–Hartmann wave-front detector. Applied optics, 2003, 42 (24), pp.4835-4840. ⟨hal-01092277⟩