Four-wave mixing

About: Four-wave mixing is a research topic. Over the lifetime, 7530 publications have been published within this topic receiving 112702 citations.

Arrangement of orthogonal polarized signals for suppressing fiber four-wave mixing in optical multichannel transmission systems

Abstract: The arrangement of signal polarization states for suppressing fiber four-wave mixing (FWM) in optical multichannel transmission is described. Experiments show that light power generated through fiber FWM becomes 0 or 1/4 of the maximum value when signals are orthogonal. Based on the experimental results, power reduction of FWM light is evaluated for various arrangements of signal polarizations, and the optimum arrangements is shown to efficiently suppress fiber FWM in a multichannel system. >

Degenerate four-wave mixing with broad-bandwidth pulsed lasers

Abstract: The steady-state theory of degenerate four-wave mixing (DFWM) with broad-bandwidth lasers is extended to treat the time dependence of the interaction allowing calculation of the intensity dependence and saturation behavior of DFWM with pulsed lasers. An experimental study of this intensity dependence as a function of laser bandwidth is reported, showing qualitative agreement with the theory. The line shape of DFWM induced by broad-bandwidth pump fields, probed by a monochromatic probe, is shown to have a Doppler-broadened profile in agreement with the theoretical predictions.

Full-band quantum-dynamical theory of saturation and four-wave mixing in graphene

Abstract: The linear and nonlinear optical response of graphene are studied within a quantum-mechanical, full-band, steady-state density-matrix model. This nonpurtabative method predicts the saturatable absorption and saturable four-wave mixing of graphene. The model includes τ1 and τ2 time constants that denote carrier relaxation and quantum decoherence, respectively. Fits to existing experimental data yield τ2<1 fs due to carrier–carrier scattering. τ1 is found to be on the timescale from 250 fs to 550 fs, showing agreement with experimental data obtained by differential transmission measurements.

Versatile and precise quantum state engineering by using nonlinear interferometers.

Abstract: The availability of photon states with well-defined temporal modes is crucial for photonic quantum technologies. Ever since the inception of generating photonic quantum states through pulse pumped spontaneous parametric processes, many exquisite efforts have been put on improving the modal purity of the photon states to achieve single-mode operation. However, because the nonlinear interaction and linear dispersion are often mixed in parametric processes, limited successes have been achieved so far only at some specific wavelengths with sophisticated design. In this paper, we resort to a different approach by exploiting an active filtering mechanism originated from interference fringe of nonlinear interferometer. The nonlinear interferometer is realized in a sequential array of nonlinear medium, with a gap in between made of a linear dispersive medium, in which the precise modal control is realized without influencing the phase matching of the parametric process. As a proof-of-principle demonstration of the capability, we present a photon pairs source using a two-stage nonlinear interferometer formed by two identical nonlinear fibers with a standard single mode fiber in between. The results show that spectrally correlated two-photon state via four wave mixing in a single piece nonlinear fiber is modified into factorable state and heralded single-photons with high modal purity and high heralding efficiency are achievable. This novel quantum interferometric method, which can improve the quality of the photon states in almost all the aspects such as modal purity, heralding efficiency, and flexibility in wavelength selection, is proved to be effective and easy to realize.

Generation of coherent UV radiation by optical wave-mixing processes in atomic potassium

Abstract: A pulsed dye-laser beam (ωL) pumped by a frequency-doubled Nd:YAG laser is focused into a heat-pipe oven containing potassium vapor (nk ≈ 1016 cm−3). Two-photon resonant four-wave and six-wave mixing processes using the potassium 8s 2S1/2 state are investigated. Thirty-two coherent UV radiation lines are generated within the range of 300–400 nm through the processes ωUV = 2ωL ± ωIR and ωUV = 2ωL − ω′IR − ω″IR ± ω‴IR, where ωIR are frequencies of laser-induced IR waves generated in the vapor near the transitions 8S–7P, 7P–7S, 7P–5D, 8S–6P, 7S–6P, 5D–6P, etc. The influence of resonant enhancement on the UV line intensities and the phase-matching condition are analyzed.