Position- and Polarization-Specific Waveguiding of Multi-Emissions in Single ZnO Nanorods
Bonghwan Chon, Johnson Truong, Matthew Hansen, Jong-in Hahm, Young J. Lee
We examine multiphoton-produced optical signals waveguided through single ZnO nanorods (NRs) using a newly developed, scanning offset-emission hyper- spectral microscopy (SOHM) technique. Specifically, we concurrently analyze waveguiding behaviors of sum-frequency generation (SFG), deep-trap emissions (DTE), and coherent anti-Stokes Raman scattering (CARS) occurring in individual ZnO NRs. SOHM acquires spectrally indexed and spatially resolved intensity maps/spectra of waveguided light intensity, while excitation/emission collection positions and light polarization are scanned. Hence, the powerful measurement capabilities of SOHM enable quantitative analyses of the different ZnO NR waveguiding behaviors specific to the multiphoton-generated emissions as a function of measurement position, light−matter interaction geometry, and the optical origin of the guided signal. We subsequently reveal the distinct waveguiding behaviors of single ZnO NRs pertaining to the SFG-, DTE-, and CARS-originated signals and discuss particularly attractive ZnO NR properties in CARS waveguiding.