We demonstrate a classical analogue of electromagnetically induced transparency (EIT) in highly flexible planar terahertz metamaterial (MM) comprised three-gap split ring resonators. The keys to achieve EIT this system are the frequency detuning and hybridization processes between two bright modes coexisting same unit cell as opposed bright-dark modes. present experimental verification two-bright mode coupling for EIT-MM context numerical results theoretical analysis based on coupled Lorentz...

We analyze the process of cascaded four-wave mixing in a high-Q microcavity and show that under conditions suitable cavity-mode dispersion, broadband frequency combs can be generated. experimentally demonstrate broadband, parametric oscillation anomalous group-velocity dispersion regime silica microsphere with an overall bandwidth greater than 200 nm.

We show that quantum frequency conversion (QFC) can overcome the spectral distinguishability common to inhomogeneously broadened solid-state emitters. QFC is implemented by combining single photons from an InAs/GaAs dot (QD) at 980 nm with a 1550 pump laser in periodically poled lithium niobate (PPLN) waveguide generate 600 signal-to-background ratio exceeding $100\ensuremath{\mathbin:}1$. Photon correlation and two-photon interference measurements confirm both photon character wave packet...

We demonstrate heralded single photon generation in a CMOS-compatible silicon nanophotonic device. The strong modal confinement and slow group velocity provided by coupled resonator optical waveguide (CROW) produced large four-wave-mixing nonlinearity coefficient gamma_eff ~4100 W^-1 m^-1 at telecommunications wavelengths. Spontaneous using degenerate pump beam 1549.6 nm created pairs 1529.5 1570.5 with coincidence-to-accidental ratio exceeding 20. A correlation measurement of the signal...

We demonstrate theoretically and experimentally that under suitable conditions high-$Q$ microspheres can exhibit anomalous dispersion, which permits phase energy matching for nonlinear optical interactions. use such dispersion control to produce either Raman or four-wave mixing parametric oscillations by changing the size of microsphere.

Abstract Bound states in the continuum (BICs) are widely studied for their ability to confine light, produce sharp resonances sensing applications and serve as avenues lasing action with topological characteristics. Primarily, formation of BICs periodic photonic band gap structures driven by symmetry incompatibility; structural manipulation or variation incidence angle from incoming light. In this work, we report two modalities driving terahertz metasurfaces. At normal incidence,...

Low-noise, tunable wavelength-conversion through nondegenerate four-wave mixing Bragg scattering in SiN(x) waveguides is experimentally demonstrated. Finite element method simulations of waveguide dispersion are used with the split-step Fourier to predict device performance. Two 1550 nm wavelength band pulsed pumps achieve conversion a 980 signal over range 5 peak efficiency ≈5%. The demonstrated process suitable for frequency quantum states light.

Single epitaxially-grown semiconductor quantum dots have great potential as single photon sources for photonic technologies, though in practice devices often exhibit nonideal behavior. Here, we demonstrate that amplitude modulation can improve the performance of quantum-dot-based sources. Starting with a bright source consisting dot fiber-coupled microdisk cavity, use synchronized to temporally filter emitted light. We observe purity, temporal overlap between successive emission events and...

High-speed electrical switching of Ge2Sb2Te5 (GST) remains a challenging task due to the large impedance mismatch between low-conductivity amorphous state and high-conductivity crystalline state. In this letter, we demonstrate an effective doping scheme using nickel reduce resistivity contrast states by nearly three orders magnitude. Most importantly, our results show that produces desired performance without adversely affecting film's optical properties. The level is approximately 2%...

We fabricate high-Q arsenic triselenide glass microspheres through a three-step resistive heating process. demonstrate quality factors greater than 2 x 10(6) at 1550 nm and achieve efficient coupling via novel scheme utilizing index-engineered unclad silicon nanowires. find that powers above 1 mW the exhibit high thermal instability, which limits their application for resonator-enhanced nonlinear optical processes.

We present experimental studies on the generation of pulsed and continuous-wave squeezed vacuum via nonlinear rotation polarization ellipse in a $^{87}$Rb vapor. Squeezing is observed for wide range input powers pump detunings D1 line, while only excess noise D2 line. The maximum squeezing -$ 1.4 \pm0.1$ dB (-2.0 corrected losses). measure -1.1 at resonance frequency $^{85}$Rb $F=3 \to F'$ transition, which may allow storage light generated by quantum memory. Using pump, with -1 200 ns pulse...

We report the polarization-dependent electromagnetic response from a series of novel terahertz (THz) metasurfaces where asymmetry is introduced through displacement two adjacent metallic arms separated by distance δ.For all polarization states, symmetric metasurface exhibits low quality (Q) factor fundamental dipole mode.By breaking symmetry, we experimentally observe secondary dipole-like mode with Q nearly 9× higher than resonance.As δ increases, f 1 redshifts and 2 blueshifts creating...

We propose and demonstrate a two-dimensional 4-bit fully optical nonvolatile memory using Ge2Sb2Te5 (GST) phase change materials, with encoding via 1550 nm laser. Using the telecom-band laser, we are able to reach deeper into material due low-loss nature of GST at this wavelength range, hence, increasing number write/read levels compared previous demonstrations, while simultaneously staying within acceptable read/write energies (maximum 60 nJ/bit for write, depending on pulses). For our...

Optical materials engineered to dynamically and selectively manipulate electromagnetic waves are essential the future of modern optical systems. In this paper, we simulate various metasurface configurations consisting periodic 1D bars or 2D pillars made ternary phase change material Ge2Sb2Te5 (GST). Dynamic switching behavior in reflectance is exploited due a drastic refractive index between crystalline amorphous states GST. Selectivity reflection transmission spectra manipulated by...

The large impedance mismatch between the highly resistive amorphous state and conductive crystalline of Ge2Sb2Te5 is an impediment for realization high-speed electrically switched optical devices. In this paper, we demonstrate that tungsten doping can reduce resistivity contrast also results in a lower resistivity. Additionally, it lowers contact resistance, improves contrast, extends face-centered-cubic up to 350 °C, with minimal impact on thermal conductivity.

Abstract Vortex reconnections are ubiquitous events found in diverse media. Here we show that vortex also occur between spatiotemporal vortices optical waves. Since exhibit orbital angular momentum (OAM), the of create a variety connected OAM states. Dispersion and diffraction can cause different reconnection pairs, depending on orientation vortices. The transverse crossing two with topological charge one produce unique loop patterns. Higher charges result arrays loops connection points....

We report an investigation on the photo-response from a GeSn-based photodetector using tunable laser with range of incident light power. An exponential increase in photocurrent and decay responsivity optical power intensity were observed at higher range. Time-resolved measurement provided evidence that indicated monomolecular bimolecular recombination mechanisms for photo-generated carriers different intensities. This establishes appropriate operation.

Abstract Programmable and reconfigurable photonics is revolutionized the next generation of Si/SiN‐based processors, optical signal processing, neural quantum networks. Ultra‐low loss phase‐change technology has enormous potential to offer energy‐efficient, extra large‐scale integrated (ELSI) nonvolatile programmable that can overcome limitations commonly used volatile energy‐hungry photonic systems. So far, most phase change materials (PCM) devices have already shown be suitable for circuit...

We describe a chip-scale, telecommunications-band frequency conversion interface designed for low-noise operation at wavelengths desirable common single photon emitters.Four-wave-mixing Bragg scattering in silicon nitride waveguides is used to demonstrate upconversion and downconversion between the 980 nm 1550 wavelength regions, with signal-to-background levels > 10 efficiency of ≈ -60 dB low continuous wave input pump powers (< 50 mW).Finite element simulations split-step Fourier method...

We employ the process of non-degenerate four-wave mixing Bragg scattering (FWM-BS) to demonstrate all-optical control in a silicon platform. In our configuration, strong, non-information-carrying pump is mixed with weak and an input signal silicon-on-insulator waveguide. Through optical nonlinearity this highly-confining waveguide, controls wavelength conversion from idler, leading controlled depletion signal. The strong pump, on other hand, plays role constant bias. work, we show...

Traditional lattice-induced transparency demonstrations are activated by varying the meta-atom lattice constant such that plasmonic and modes interfere. Here we report on observation of enhanced coupling between two eigenmodes (first- second-order) parameter in a symmetric split ring resonator design. The higher-order quasi-dark mode blueshifts, introducing strong with fundamental bright for periods above 345 μm. Numerical simulations verified experimentally supplemented two-oscillator model...

Low-cost spectroscopy has received a great deal of attention in recent years applications such as food inspection, disease detection, and manufacturing. Current spectroscopic systems rely on multiple optical components, making them mechanically fragile systems. In our previous work, we demonstrated the use Fourier filtering using thin dielectric films. The sampling effect from cavity resonances can be used to decompose signal into its components. Although films were deposited directly face...

We present theoretical and experimental results on the generation detection of pulsed, relative-intensity squeezed light in a hot Rb87 vapor. The intensity noise correlations between pulsed probe beam its conjugate, generated through nearly-degenerate four-wave mixing double-lambda system, are studied numerically measured experimentally via time-resolved balanced detection. predict observe about -1 dB relative squeezing with 50 nanosecond pulses at 1 MHz repetition rate. (-1.34 corrected for loss).

We experimentally demonstrate spectral broadening and shaping of exponentially-decaying nanosecond pulses via nonlinear mixing with a phase-modulated pump in periodically poled lithium niobate (PPLN) waveguide. 1550 nm light is imprinted temporal phase used to upconvert weak 980 pulse 600 while simultaneously the spectrum that Lorentzian up 10 times shorter. While current experimental demonstration for shaping, we also provide numerical study showing feasibility subsequent correction achieve...