Comparison of Linear and Nonlinear Optical Properties of ZnO Nanorods

Abstract

Photoluminescence emission from, and third harmonic generation by, ZnO nanorod samples grown using both low and high temperature methods are reported. Our results clearly show that PL emission at cryogenic temperatures from low temperature grown samples is both significantly weaker in intensity and spectrally broader than that from high temperature grown samples. The third harmonic generation efficiency of samples grown by both the low temperature and high temperature methods are however comparable to one another, and much larger than third harmonic generation at a bare quartz surface. Intensity dependence and interferometric frequency resolved optical gating measurements are used to study the third harmonic generation from both sample types. Laser pulse parameters are extracted for pulses subjected to both high and low chirp and our results indicate that ZnO nanostructures grown by low temperature methods allow excellent characterization of ultrafast pulses and are efficient for third harmonic generation and thus are excellent candidate materials for a variety of technological applications.