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We refer to Canonical Resonant Four-Wave-Mixing when only four (three in the degenerate case) modes of the cavity are able to interact through this parametric process; thereby inhibiting competing parametric processes. This condition is achieved in the recently introduced photonic crystal parametric oscillator, Marty et al. Nat. Photonics, 15, 53 (2021). Here, we discuss extensively the properties of this parametric source and compare the design with other geometries of photonic crystal resonators. Based on a statistical study over more than 100 resonators and 10 parametric oscillators, robustness against fabrication tolerances is assessed, performances are evaluated in terms of average values and their dispersion, and the dependence on the main parameters is shown to follow the theoretical scaling. The lowest pump power at threshold is $\approx$40 $\mu$W and we show the existence of a minimum value of the cavity photon lifetime as a condition for parametric oscillation, which is related to three photon absorption.

Nonlinear optical resonators allow the coherent conversion of photons, yet fabrication tolerances limit their wavelength accuracy. Introducing periodic modulation in ring resonators is shown to allow robust and predictable selection of the converted photons.

We theoretically and experimentally investigate type II second harmonic generation in III-V-on-insulator wire waveguides. We show that the propagation direction plays a crucial role and that longitudinal field components can be leveraged for robust and efficient conversion. We predict that the maximum theoretical conversion is larger than that of type I second harmonic generation for similar waveguide dimensions and reach an experimental conversion efficiency of 12%/W, limited by the propagation loss.

We report a new class of optical parametric oscillators, based on a 20-µm-long semiconductor photonic crystal cavity and operating at telecom wavelengths. Because the confinement results from Bragg scattering, the optical cavity contains a few modes, approximately equispaced in frequency. Parametric oscillation is reached when these high-quality-factor modes are thermally tuned into a triply resonant configuration, whereas any other parametric interaction is strongly suppressed. The lowest pump power threshold is estimated to be 50–70?µW. This source behaves as an ideal degenerate optical parametric oscillator, addressing the needs in the field of quantum optical circuits and paving the way towards the dense integration of highly efficient nonlinear sources of squeezed light or entangled photons pairs.

Generating and amplifying light in silicon (Si) continues to attract significant attention due to the possibility of integrating optical and electronic components in a single material platform. Unfortunately, silicon is an indirect band gap material and therefore an inefficient emitter of light. With the rise of integrated photonics, the search for silicon-based light sources has evolved from a scientific quest to a major technological bottleneck for scalable, CMOS-compatible, light sources. Recently, emerging two-dimensional materials have opened the prospect of tailoring material properties based on atomic layers. Few-layer phosphorene, which is isolated through exfoliation from black phosphorus (BP), is a great candidate to partner with silicon due to its layer-tunable direct band gap in the near-infrared where silicon is transparent. Here we demonstrate a hybrid silicon optical emitter composed of few-layer phosphorene nanomaterial flakes coupled to silicon photonic crystal resonators. We show single-mode emission in the telecommunications band of 1.55 μm (Eg= 0.8 eV) under continuous wave optical excitation at room temperature. The solution-processed few-layer BP flakes enable tunable emission across a broad range of wavelengths and the simultaneous creation of multiple devices. Our work highlights the versatility of the Si-BP material platform for creating optically active devices in integrated silicon chips.

Ga_0.51In_0.49P is a promising candidate for thermally tunable nanophotonic devices due to its low thermal conductivity. In this work we study its thermo-optical response. We obtain the linear thermo-optical coefficient dn/dT=2.0±0.3·10^−4  K^−1 by investigating the transmission properties of a single mode-gap photonic crystal nanocavity.

We demonstrated a twofold acceleration of the fast time constant characterizing the recovery of a p-doped indium-phosphide photonic crystal all-optical gate. Time-resolved spectral analysis is compared to a three-dimensional drift-diffusion model for the carrier dynamics, demonstrating the transition from the ambipolar to the faster minority carrier dominated diffusion regime. This opens the perspective for faster yet efficient nanophotonic all-optical gates.

Heat dissipation is improved in nonlinear III-V photonic crystal waveguides owing to the hybrid III-V/Silicon integration platform, allowing efficient four-wave mixing in the continuous-wave regime. A conversion efficiency of −17.6  dB is demonstrated with a pump power level below 100 mW in a dispersion-engineered waveguide with a flat group index of 28 over a 10 nm bandwidth.

The dispersion of a coupled resonator optical waveguide made of photonic crystal mode-gap cavities is pronouncedly asymmetric. This asymmetry cannot be explained by the standard tight binding model. We show that the fundamental cause of the asymmetric dispersion is the inherent dispersive cavity mode profile; i.e., the mode wave function depends on the driving frequency, not the eigenfrequency. This occurs because the photonic crystal cavity resonances do not form a complete set. We formulate a dispersive mode coupling model that accurately describes the asymmetric dispersion without introducing any new free parameters.

We demonstrate the generation of an octave-spanning supercontinuum in InGaP membrane waveguides on a silicon substrate pumped by a 1550-nm femtosecond source. The broadband nature of the supercontinuum in these dispersion-engineered high-index-contrast waveguides is enabled by dispersive wave generation on both sides of the pump as well as by the low nonlinear losses inherent to the material. We also measure the coherence properties of the output spectra close to the pump wavelength and find that the supercontinuum is highly coherent at least in this wavelength range.

We present theory and measurements of disorder-induced losses for low loss 1.5 mm long slow light photonic crystal waveguides. A recent class of dispersion engineered waveguides increases the bandwidth of slow light and shows lower propagation losses for the same group index. Our theory and experiments explain how Bloch mode engineering can substantially reduce scattering losses for the same slow light group velocity regime.

We numerically study a narrowband semiconductor integrated source of counterpropagating twin photons for line-of-sight experiments in quantum key distribution. Considering the air transparency and the availability of silicon avalanche photodiodes to be around 770 nm, we focus on GaN- and ZnSe-based quadratically nonlinear multilayer waveguides. The design of a quasi-phase-matched χ^(2) profile in the growth direction allows us to generate 3×10^5 guided photon pairs per second for a pump power around 300 mW.

In this Letter we demonstrate heralded single-photon generation in a III–V semiconductor photonic crystal platform through spontaneous four-wave mixing. We achieve a high brightness of 3.4×10^7  pairs·s^−1 nm^−1 W^−1 facilitated through dispersion engineering and the suppression of two-photon absorption in the gallium indium phosphide material. Photon pairs are generated with a coincidence-to-accidental ratio over 60 and a low g^(2)(0) of 0.06 proving nonclassical operation in the single photon regime.

High-resolution infrared absorption spectroscopy of acetylene gas is demonstrated in a dispersion-engineered photonic crystal waveguide under slow-light propagation. Experimental enhancement factors of 0.31 and 1.00 are obtained for TE and TM polarization, respectively, for group indices ranging from 1.5 to 6.7. The dependence of molecular absorption on the evanescent electric-field distribution and on the group index under structural slow-light illumination is experimentally demonstrated and confirmed by time-domain simulations.

We report on a chip scale parametric amplifier based on a GaInP photonic crystal waveguide. The amplifier operates with both pump and signal in the 1550 nm wavelength range and offers an on-chip gain of 11 dB (5 dB including the 6 dB coupling losses) when pumped at only 800 mW. It enables us, therefore, to incorporate the many advantages of parametric amplification within photonic chips for optical communication applications.

We investigate four-wave mixing (FWM) in GaInP 1.5 mm long dispersion engineered photonic crystal waveguides. We demonstrate an 11 nm FWM bandwidth in the CW mode and a conversion efficiency of −24 dB in the quasi-CW mode. For picosecond pump and probe pulses, we report a 3 dB parametric gain and nearly a −5 dB conversion efficiency at watt-level peak pump powers.

We examine the effects of multiphoton absorption, free carriers, and disorder-induced linear scattering in slow-light photonic crystal waveguides. We derive an analytic formulation for self-phase modulation including the group velocity scaling of the nonlinear phase shift in materials limited by three-photon absorption as a representative nonlinear process. We investigate the role of free carriers and derive an approximate critical intensity at which these effects begin to strongly modify the optical field. This critical intensity is employed to determine an optimal group index for the self-phase modulation in the slow-light devices. These observations are confirmed with numerical modeling.

We haves realized and measured a GaAs nanocavity in a slab photonic crystal based on the design by Kuramochi et al. [Appl. Phys. Lett. 88, 041112 (2006)]. We measure a quality factor Q=700,000, which proves that ultrahigh Q nanocavities are also feasible in GaAs. We show that owing to larger two-photon absorption in GaAs nonlinearities appear at the microwatt level and will be more functional in gallium arsenide than in silicon nanocavities.

We propose a design for patterned metal-coated surfaces allowing efficient broadband coupling of radiation to a fully localized surface cavity mode, resulting in a zero-focal-length concentrator. This finite structure exploits the interplay of a defect mode cavity with a coupling grating and is investigated through the modal expansion method and finite-difference time domain calculations.

We show that one-dimensional parametric spatial solitons undergo temporal instability that leads to their breakup into spatiotemporal patterns with a characteristic snakelike shape.

We investigate the existence and stability of parametric gap solitons in ?^2 media in the limit of Kerr-equivalent nonlinearities. We reveal soliton branching (bistability) described by an explicit criterion. Unlike in other optical solitons, both branches of gap solitons can be unstable owing to oscillatory instabilities. Despite these mechanisms stable gap solitons do exist.

We show that a semiconductor nanocavity where the dominant nonlinear mechanism is the refractive index change induced by carriers generated through two-photon absorption can become unstable, exhibiting the onset of spontaneous oscillations (self-pulsing). The linear stability analysis, validated through numerical integration of a mean-field model, leads us to predict oscillations to take place typically in the 10-ps range at input power levels of the order of 15 mW. [ABSTRACT FROM AUTHOR]

The Green's function formalism is used in order to model the diffusion of free carriers in nonlinear semiconductor nanoscale resonators. In combination with the time-dependent coupled-mode equations, this leads to excellent agreement with measurements carried on a variety of samples and materials, using a minimal set of fitting parameters. The role of the geometry of the cavity is evidenced and the influence of linear and nonlinear absorption on the response of the resonator is discussed. This model can handle a broad range of phenomena: switching, self-pulsing, including resonant four-wave mixing. [ABSTRACT FROM AUTHOR]

We investigate the impact of a finite response time of Kerr nonlinearities over the onset of spontaneous oscillations (self-pulsing) occurring in a nanocavity. The complete characterization of the underlying Hopf bifurcation in the full parameter space allows us to show the existence of a critical value of the response time and to envisage different regimes of competition with bistability. The transition from a stable oscillatory state to chaos is found to occur only in cavities which are detuned far off-resonance, which turns out to be mutually exclusive with the region where the cavity can operate as a bistable switch. [ABSTRACT FROM AUTHOR]

Phase-sensitive parametric interactions can selectively process the two complex quadratures of the optical field. We implement phase-sensitive amplification in a large band-gap semiconductor photonic crystal waveguide in order to avoid two-photon absorption and free-carrier-related effects. Experimentally, an extinction ratio of 15 dB is achieved in a 1.5-mm-long photonic crystal waveguide, at a peak pump power of about 600 mW. We show that cascaded parametric interaction has a strong impact on squeezing and phase-sensitive extinction ratio and that this depends on the dispersion profile of the waveguide. [ABSTRACT FROM AUTHOR]