Optical second-harmonic generation, thanks to its coherent nature, is a suitable signal for interferometric measurements such as digital holography, a well-established imaging technique that allows recovery of complex diffraction wave fields from which it is possible to extract both amplitude-contrast and quantitative phase images. Here, we report on a multifunctional form of microscopy, namely, second-harmonic generation digital holographic microscopy. As a proof of concept, we have investigated the second-harmonic signal generated at the glass/air interface of a microscope slide under focused femtosecond laser illumination, and we propose, for the first time to our knowledge, a representation and interpretation of the recovered phase. In this simple yet educative case study, we observe that the second harmonic is generated by the axial component of the incident field polarization.
© 2009 Optical Society of America
Original Manuscript: April 23, 2009
Revised Manuscript: June 12, 2009
Manuscript Accepted: June 22, 2009
Published: August 10, 2009
Vol. 4, Iss. 10 Virtual Journal for Biomedical Optics
Etienne Shaffer, Nicolas Pavillon, Jonas Kühn, and Christian Depeursinge, "Digital holographic microscopy investigation of second harmonic generated at a glass/air interface," Opt. Lett. 34, 2450-2452 (2009)