Quantum Optics Seminar: Ryan Hamerly

Dispersion-Engineered Photonics for Quantum Information and Light Sources

Significant progress has been made towards high-performance, nonlinear nanophotonics through engineering the Q-factor and volume of photonic cavities.  But waveguided optical systems also possess a temporal dimension whose control is often neglected.  This talk gives two examples of how engineering the temporal properties of light in nonlinear resonators can enable new phenomena and break the conventional tradeoffs associated with single-mode optics.  (1) First, I introduce the concept of temporal trapping in ring resonators, where cross-phase modulation (XPM) and group-velocity dispersion counteract to form trapped states, “flying cavities” that confine the light along the resonator’s axial dimension, reducing the effective mode volume (and thus increasing the effective nonlinearity) by orders of magnitude.  Numerical models confirm the possibility of high-fidelity χ(2) quantum gates, circumvent-ting the Shapiro no-go result on pulsed quantum nonlinear optics, and with order-of-magnitude calculations, we show a reasonable path to achieving room-temperature strong coupling g/κ > 1 in LiNbO3 resonators.  (2) Next, I discuss the new opportunities χ(2) poses for lightsource development and introduce the quadrature-amplitude-modulated (QAM) OPO, a new type of frequency comb that simultaneously achieves stable turn-key operation, high efficiency, flat spectrum, broad dispersion-limited bandwidth, and rapid (electro-optic) tunability.