Abstract-Backward terahertz difference frequency generation via modal phase-matching in a planar LiNbO3 waveguide

B. N. Carnio and A. Y. Elezzabi

https://www.osapublishing.org/ol/abstract.cfm?uri=ol-45-13-3657

The backward difference frequency generation process is used to produce narrowband terahertz radiation via modal phase-matching in a SiO2-LiNbO3${\mathrm{S}\mathrm{i}\mathrm{O}}_2\text{-}{\mathrm{L}\mathrm{i}\mathrm{N}\mathrm{b}\mathrm{O}}_3$-air planar waveguide. The TM0${\mathrm{T}\mathrm{M}}_0$ pump mode, TE0${\mathrm{T}\mathrm{E}}_0$ signal mode, and TE0${\mathrm{T}\mathrm{E}}_0$ or TE2${\mathrm{T}\mathrm{E}}_2$ idler modes are selected to satisfy the backward difference frequency generation phase-matching condition, thus allowing narrowband (i.e., <100GHz$<100\mathrm{G}\mathrm{H}\mathrm{z}$ linewidth) terahertz radiation generation in the spectral range of 2.4–3.2 THz. To date, this is the first investigation of terahertz radiation generation in a waveguide via the modal phase-matched backward difference frequency generation process.

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