Quantitative phase microscopy by digital holography provides direct access to the phase profile of a transparent subject with high precision. This is useful for observing phenomena that modulate phase, but are otherwise difficult or impossible to detect. In this letter, a carefully constructed digital holographic apparatus is used to measure optically induced thermal lensing with an optical path difference precision of less than 1 nm. Furthermore, by taking advantage of the radial symmetry of a thermal lens, such data are processed to determine the absorption coefficient of transparent media with precisions as low as 1 × 10<sup>-5</sup> cm<sup>-1</sup> using low power (30 mW) continuous wave (CW) excitation.
© 2011 Chinese Optics Letters
Digital Holography and 3D Imaging 2011 (2011) Applied Optics
David C. Clark and Myung K. Kim, "High-precision method for measuring the photothermal properties of transparent media with digital holography (Invited Paper)," Chin. Opt. Lett. 9, 120001- (2011)