Generation of Complex Quantum States Via Integrated Frequency Combs

The generation of optical quantum states on an integrated platform will enable low cost and accessible advances for quantum technologies such as secure communications and quantum computation. We demonstrate that integrated quantum frequency combs (based on high-Q microring resonators made from a CMOS-compatible, high refractive-index glass platform) can enable, among others, the generation of heralded single photons, cross-polarized photon pairs, as well as bi- and multi-photon entangled qubit states over a broad frequency comb covering the S, C, L telecommunications band, constituting an important cornerstone for future practical implementations of photonic quantum information processing

Linearizing nonlinear optics

In the framework of linear optics, light fields do not interact with each other in a medium. Yet, when their field amplitude becomes comparable to the electron binding energies of matter, the nonlinear motion of these electrons emits new dipole radiation whose amplitude, frequency and phase differ from the incoming fields. Such high fields are typically achieved with ultra-short, femtosecond (1fs = 10-15 sec.) laser pulses containing very broad frequency spectra. Here, the matter not only couples incoming and outgoing fields but also causes different spectral components to interact and mix through a convolution process. In this contribution, we describe how frequency domain nonlinear optics overcomes the shortcomings arising from this convolution in conventional time domain nonlinear optics1. We generate light fields with previously inaccessible properties because the uncontrolled coupling of amplitudes and phases is turned off. For example, arbitrary phase functions are transferred linearly to the second harmonic frequency while maintaining the exact shape of the input power spectrum squared. This nonlinear control over output amplitudes and phases opens up new avenues for applications based on manipulation of coherent light fields. One could investigate c.f. the effect of tailored nonlinear perturbations on the evolution of discrete eigenmodes in Anderson localization2. Our approach might also open a new chapter for controlling electronic and vibrational couplings in 2D-spectroscopy3 by the geometrical optical arrangement

Decoupling frequencies, amplitudes and phases in nonlinear optics

In linear optics, light fields do not mutually interact in a medium. However, they do mix when their field strength becomes comparable to electron binding energies in the so-called nonlinear optical regime. Such high fields are typically achieved with ultra-short laser pulses containing very broad frequency spectra where their amplitudes and phases are mutually coupled in a convolution process. Here, we describe a regime of nonlinear interactions without mixing of different frequencies. We demonstrate both in theory and experiment how frequency domain nonlinear optics overcomes the shortcomings arising from the convolution in conventional time domain interactions. We generate light fields with previously inaccessible properties by avoiding these uncontrolled couplings. Consequently, arbitrary phase functions are transferred linearly to other frequencies while preserving the general shape of the input spectrum. As a powerful application, we introduce deep UV phase control at 207 nm by using a conventional NIR pulse shaper

High-order Radio Frequency Differentiation via Photonic Signal Processing with an Integrated Micro-resonator Kerr Optical Frequency Comb Source

We demonstrate the use of integrated micro-resonator based optical frequency comb sources as the basis for transversal filtering functions for microwave and radio frequency photonic filtering and advanced functions.Comment: 8 pages, 7 figures, 46 References. arXiv admin note: substantial text overlap with arXiv:1512.01741, arXiv:1512.0630