Abstract

The recently-introduced use of integrated frequency combs (on-chip light sources with a broad spectrum of evenly-spaced frequency modes, generated by four-wave mixing in optically-excited nonlinear microcavities) below optical parametric oscillation threshold for quantum state generation has provided a solution for scalable and multi-mode quantum sources [1,2]. Pulsed quantum frequency combs, in particular, are the basis for time-bin entanglement [2] and enable the generation of single-frequency-mode photons [3], required for scaling state complexity towards e.g. multi-photon states [2]. However, the generation schemes for such pulsed combs have up to now relied on microcavity excitation via external pulsed laser sources. The bulkiness of these lasers is incompatible with an approach towards full source integration, while furthermore, the excitation of single microcavity resonances (often having resonance linewidths of ~MHz-order) is energy-inefficient, given that for a stable operation usually most of the laser bandwidth does not contribute to the resonance excitation.

© 2017 IEEE