Digital holographic microscopy investigation of second harmonic generated at a glass/air interface

摘要

Optical second-harmonic generation, thanks to its coherent nature, is a suitable signal for interferometricnmeasurements such as digital holography, a well-established imaging technique that allows recovery of com-nplex diffraction wave fields from which it is possible to extract both amplitude-contrast and quantitativenphase images. Here, we report on a multifunctional form of microscopy, namely, second-harmonic generationndigital holographic microscopy. As a proof of concept, we have investigated the second-harmonic signal gen-nerated at the glass/air interface of a microscope slide under focused femtosecond laser illumination, and wenpropose, for the first time to our knowledge, a representation and interpretation of the recovered phase. Innthis simple yet educative case study, we observe that the second harmonic is generated by the axial compo-nnent of the incident field polarization. © 2009 Optical Society of America