Burgess, Ian B.Zhang, YinanMcCutcheon, Murray W.Rodriguez, Alejandro W.Bravo-Abad, JorgeJohnson, Steven G.Loncar, Marko2019-10-032009Burgess, Ian B., Yinan Zhang, Murray W. McCutcheon, Alejandro W. Rodriguez, Jorge Bravo-Abad, Steven G. Johnson, and Marko Loncar. 2009. “Design of an Efficient Terahertz Source Using Triply Resonant Nonlinear Photonic Crystal Cavities.” Optics Express 17 (22): 20099. https://doi.org/10.1364/oe.17.020099.1094-4087http://nrs.harvard.edu/urn-3:HUL.InstRepos:41461254We propose a scheme for efficient cavity-enhanced nonlinear THz generation via difference-frequency generation (DFG) processes using a triply resonant system based on photonic crystal cavities. We show that high nonlinear overlap can be achieved by coupling a THz cavity to a doubly-resonant, dual-polarization near-infrared (e.g. telecom band) photonic-crystal nanobeam cavity, allowing the mixing of three mutually orthogonal fundamental cavity modes through a chi((2)) nonlinearity. We demonstrate through coupled-mode theory that complete depletion of the pump frequency -i.e., quantum-limited conversion - is possible. We show that the output power at the point of optimal total conversion efficiency is adjustable by varying the mode quality (Q) factors.en-USJournal Article2019-10-0310.1364/OE.17.020099