Near-Field Infrared Sum-Frequency Generation Imaging of Chemical Vapor Deposited Zinc Selenide

摘要

Infrared sum-frequency generation (SFG) has been detected with near-field scanning optical m (NSOM) for the first time. SFG NSOM images of a chemical vapor deposited (CVD) disk of zinc selenide were recorded as a function of infrared (lR) wavelengths ranging from 3.1 to 4.4 lim from an amplified femtosecond laser. Striation patterns, which are not observed in the topography, were detected in the optical images and exhibited increased SFG in comparison to homogeneous regions of the semiconductor. SFG images were demonstrated to have -)j2O spatial resolution in comparison to the IR wavelengths used to produce the sum frequency.