Direct current (DC) converters play an essential role in electronic circuits. Conventional high-efficiency DC voltage converters, especially step-up type, rely on switch-mode operation, where energy is periodically stored within and released from inductors and/or capacitors connected in a variety of circuit topologies. However, since these energy storage components, especially inductors, are difficult to scale down, miniaturization of switching converters for on-chip or in-package electronics faces fundamental challenges. Furthermore, the resulting switching currents produce electromagnetic noise, which can cause interference problems in nearby circuits, and even acoustic noise and mechanical vibrations that deteriorate the environment. In order to overcome the limitations of switch-mode converters, photonic transformers, where voltage conversion is achieved through the use of light emission and detection processes, have been demonstrated. However, the demonstrated efficiency is significantly below that of the switch-mode converter. Here we perform a theoretical analysis based on detailed balance, which shows that with a monolithically integrated design that enables efficient photon transport, the photonic transformer can operate with a near-unity conversion efficiency and high voltage conversion ratio. We validate the theoretical analysis with an experiment on a transformer constructed with off-the-shelf discrete components. Our experiment showcases near noiseless operation, as well as a voltage conversion ratio that is significantly higher than obtained in previous photonic transformer works. Our finding points to a high-performance optical solution to miniaturizing DC power converters for electronics and improving the electromagnetic compatibility and quality of electrical power.
Optomechanical (OM) cavities enable coupling of near-infrared light and GHz-frequency acoustic waves in wavelength-scale volumes. When driven in the phonon lasing regime, an OM cavity can perform simultaneously as a nonlinear mixer and a local oscillator -- at integer multiples of the mechanical resonance frequency -- in the optical domain. In this work, we use this property to demonstrate all-optical frequency down- and up-conversion of MHz-bandwidth orthogonal frequency division multiplexed signals compliant with the IEEE 802.16e WiMAX wireless standard at microwave frequencies. To this end,…
We demonstrate an optical data wavelength converter based on an electrically driven photonic molecule structure comprising two coupled active silicon microring resonators. The converter, supplied by a continuous-wave (CW) microwave drive signal equal in frequency to the desired wavelength shift, replicates an input optical signal at a new wavelength. The optical coupled-cavity system matches supermode resonances to the input and wavelength-converted optical waves maximizing the conversion efficiency. Two device designs that perform wavelength up- and down-conversion by 0.19 nm (24 GHz) with -1…
An experimental comparison of the conversion gain and harmonic distortion performance between Switching and Modulation architectures of an all-optical photonic sampler mixer up-converter using a Semiconductor Optical Amplifier-based Mach-Zehnder Interferometer (SOA-MZI) is presented. The process of frequency up-conversion from 1 GHz to 9 GHz is evaluated. Because of their different principle of operation, the Switching architecture demonstrates higher positive conversion gain by approximately 6 dB and 8 dB for standard and differential configuration, respectively, while the Modulation architec…
Photonic nanostructures simultaneously maximizing spectral and spatial overlap between fundamental and second-harmonic confined modes are highly desirable for enhancing second-order nonlinear effects in nonlinear media. These conditions have thus far remained challenging to satisfy in photonic crystal cavities because of the difficulty in designing a band gap at the second-harmonic frequency. Here, we solve this issue by using instead a bound state in the continuum at that frequency, and we design a doubly-resonant photonic crystal slab cavity with strongly improved figures of merit for nonlin…
Based on the interplay between photoionization and Raman effect in gas-filled photonic crystal fibers, we propose a new optical device to control frequency-conversion of ultrashort pulses. By tuning the input-pulse energy, the output spectrum can be either down-converted, up-converted, or even frequency-shift compensated. For low input energies, Raman effect is dominant and leads to a redshift that increases linearly during propagation. For larger pulse energies, photoionization starts to take over the frequency conversion process, and induces a strong blueshift. We have found also that the fi…
A novel photonics-based RF reception approach is proposed as a competitive solution to meet the current challenges of photonic-based approaches and to realize high performances at the same time. The proposed approach adopts the superheterodyne configuration by a combination manner of electronic techniques and photonic techniques, including the ultrawideband generation of optical LO, the two-stage photonic superheterodyne frequency conversion and the real-time IF compensation. An engineering prototype has been developed and its performance has been evaluated in the laboratory environment. The e…
We demonstrate enhanced second harmonic generation in a gallium phosphide photonic crystal waveguide with a measured external conversion efficiency of 5$\times10^{-7}$/W. Our results are promising for frequency conversion of on-chip integrated emitters having broad spectra or large inhomogeneous broadening, as well as for frequency conversion of ultrashort pulses.
Low-noise frequency conversion of single photons is a critical tool in establishing fibre-based quantum networks. We show that a single photonic crystal fibre can achieve frequency conversion by Bragg-scattering four-wave mixing of source photons from an ultra-broad wavelength range by engineering a symmetric group velocity profile. Furthermore, we discuss how pump tuning can mitigate realistic discrepancies in device fabrication. This enables a single highly adaptable frequency conversion interface to link disparate nodes in a quantum network via the telecoms band.
We present a photonic reservoir computing, relying on a non-linear phase-to-amplitude mapping process, able to classify in real-time multi-Gbaud time traces subject to transmission effects. This approach delivers an all-optical, low-power neuromorphic dispersion compensator.
Transfer of amplitude and phase noise from a continuous wave optical pump to the repetition rate of a Kerr frequency comb is studied theoretically, with focus on generation of spectrally pure radio frequency (RF) signals via demodulation of the frequency comb on a fast photodiode. It is shown that both the high order chromatic dispersion of the resonator spectrum and frequency-dependent quality factor of the resonator modes facilitate the optical-to-RF noise conversion that limits spectral purity of the RF signal.
Typically, photonic waveguides designed for nonlinear frequency conversion rely on intuitive and established principles, including index guiding and band gap engineering, and are based on simple shapes with high degrees of symmetry. We show that recently developed inverse-design techniques can be applied to discover new kinds of microstructured fibers and metasurfaces designed to achieve large nonlinear frequency conversion efficiencies. As a proof of principle, we demonstrate complex, wavelengthscale chalcogenide glass fibers and gallium phosphide metasurfaces exhibiting some of the largest n…
We show how the ability to slow down, amplify, and capture fast transient events can produce high-throughput real-time instruments ranging from digitizers to imaging flow cytometers for detection of rare diseased cells in blood.
Four-wave mixing is observed in a silicon W1 photonic crystal waveguide. The dispersion dependence of the idler conversion efficiency is measured and shown to be enhanced at wavelengths exhibiting slow group velocities. A 12-dB increase in the conversion efficiency is observed. Concurrently, a decrease in the conversion bandwidth is observed due to the increase in group velocity dispersion in the slow-light regime. The experimentally observed conversion efficiencies agree with the numerically modeled results.
Electro-optic phase modulators are critical components in modern communication, microwave photonic, and quantum photonic systems. Important for these applications is to achieve modulators with low half-wave voltage at high frequencies. Here we demonstrate an integrated phase modulator, based on a thin-film lithium niobate platform, that simultaneously features small on-chip loss (~ 1 dB) and low half-wave voltage over a large spectral range (3.5 - 4.5 V at 5 - 40 GHz). By driving the modulator with a strong 30-GHz microwave signal corresponding to around four half-wave voltages, we generate an…
We propose to use the integrated aluminum nitride waveguide with engineered width variation to achieve optical frequency conversion based on $χ^{(2)}$ nonlinear effect on a photonic chip. We show that in an adiabatically tapered waveguide, the frequency conversion has a much broader bandwidth and the efficiency within the bandwidth is almost constant, which is favorable for short pulses. We demonstrate both analytically and numerically an "area law" for the frequency conversion, i.e. the product of bandwidth and efficiency is conserved as long as peak conversion efficiency does not saturate. T…
Tremendous scientific progress has been achieved through the development of nonlinear integrated photonics. Prominent examples are Kerr-frequency-comb generation in micro-resonators, and supercontinuum generation and frequency conversion in nonlinear photonic waveguides. High conversion efficiency is enabling for applications of nonlinear optics, including such broad directions as high-speed optical signal processing, metrology, and quantum communication and computation. In this work, we demonstrate a gallium-arsenide-on-insulator (GaAs) platform for nonlinear photonics. GaAs has among the hig…
We report on nonlinear frequency conversion from the telecom range via second harmonic generation (SHG) and third harmonic generation (THG) in suspended gallium nitride slab photonic crystal (PhC) cavities on silicon, under continuous-wave resonant excitation. Optimized two-dimensional PhC cavities with augmented far-field coupling have been characterized with quality factors as high as 4.4$\times10^{4}$, approaching the computed theoretical values. The strong enhancement in light confinement has enabled efficient SHG, achieving normalized conversion efficiency of 2.4$\times10^{-3}$ $W^{-1}$, …
In this theoretical study, we show that a simple endlessly single-mode photonic crystal fiber can be designed to yield, not just two, but three zero-dispersion wavelengths. The presence of a third dispersion zero creates a rich phase-matching topology, enabling enhanced control over the spectral locations of the four-wave-mixing and resonant-radiation bands emitted by solitons and short pulses. The greatly enhanced flexibility in the positioning of these bands has applications in wavelength conversion, supercontinuum generation and pair-photon sources for quantum optics.
The light propagation through one-dimensional photonic crystal using Four-wave mixing (FWM) nonlinear process is modeled. The linear and nonlinear indexes of refraction are approximated with the first Fourier harmonic term. Based on this approximation, a complete set of coupled wave equations, including pump fields depletion, for description of FWM process and conversion efficiency from pump to signal and idler waves for periodic structures is presented. The derived coupled wave equations are evaluated numerically. Some of important system parameters effects on FWM performance are investigated…
This paper demonstrates the operation of a universal RF photonic circuit that consists of a generalized Mach Zehnder Interferometer architecture with its Nx1 combiner replaced by a NxN optical DFT network. The proposed circuit architecture can be used for SSB modulation, frequency up-conversion/down-conversion, frequency multiplication and phase correlated subcarrier generation based on the choice of output ports and dimension (N) of the circuit. An alternative representation of the circuit is also reported with the aim of a systematic demultiplexing. A transfer matrix approach is used to deve…
In the quantum world, a single particle can have various degrees of freedom to encode quantum information. Controlling multiple degrees of freedom simultaneously is necessary to describe a particle fully and, therefore, to use it more efficiently. Here we introduce the transverse waveguide-mode degree of freedom to quantum photonic integrated circuits, and demonstrate the coherent conversion of a photonic quantum state between path, polarization and transverse waveguide-mode degrees of freedom on a single chip. The preservation of quantum coherence in these conversion processes is proven by si…
Quantum frequency conversion of single photons between wavelength bands is a key enabler to realizing widespread quantum networks. We demonstrate the quantum frequency conversion of a heralded 1551 nm photon to any wavelength within an ultrabroad (1226 - 1408 nm) range in a group-velocity-symmetric photonic crystal fiber (PCF), covering over 150 independent frequency bins. The target wavelength is controlled by tuning only a single pump laser wavelength. We find internal, and total, conversion efficiencies of 12(1)% and 1.4(2)%, respectively. For the case of converting 1551 nm to 1300 nm we me…
Broadband-tunable sources of circularly-polarized light are crucial in fields such as laser science, biomedicine and spectroscopy. Conventional sources rely on nonlinear wavelength conversion and polarization control using standard optical components, and are limited by the availability of suitably transparent crystals and glasses. Although gas-filled hollow-core photonic crystal fiber provides pressure-tunable dispersion, long well-controlled optical path-lengths, and high Raman conversion efficiency, it is unable to preserve circular polarization state, typically exhibiting weak linear biref…
Coherent ultraviolet (UV) light has many uses, for example in the study of molecular species relevant in biology and chemistry. Very few if any laser materials offer UV transparency along with damage-free operation at high photon energies and laser power. Here we report efficient generation of deep and vacuum UV light using hydrogen-filled hollow-core photonic crystal fiber (HC-PCF). Pumping above the stimulated Raman threshold at 532 nm, coherent molecular vibrations are excited in the gas, permitting highly efficient thresholdless wavelength conversion in the UV. The system is uniquely press…
Exploiting topological ideas has been a major theme in modern photonics, which provides unprecedented opportunities to design photonic devices with robustness against defects and flaws. While most previous works in topological photonics have focused on band theory, recent theoretical advances extend the topological concepts to the analysis of scattering matrices and suggest a topological route to complete polarization conversion (CPC), a unique photonic phenomenon without an electronic counterpart. Here, we report on the experimental observation of the topological effect in reflection matrices…
This paper gives a personal global point of view on two sciences: electronics and photonics towards plasmonics and solar energy conversion. The new research directions in these two sciences are pointed out by comparison and in the perspective of future new solar devices. A parallel and the equivalence between electronics and photonics are presented. Starting from electron in electronics, photon, solitons and plasmons in photonics, electrical cables - optical fibers, plasmonic wave guides, electrical circuits - optical circuits, electrical transistors - optical transistors, plasmonster, electri…
We study the light propagation in one-dimensional photonic crystal via nonlinear Four Wave Mixing (FWM) process. The linear and nonlinear refractive indexes are approximated with the first Fourier harmonic term. A system of the nonlinear coupled mode equations (NLCMEs), including pump fields depletion is derived for FWM process and steady state analysis is presented numerically. Also some of important system parameters' effects on FWM process are investigated. It has been shown that, although we have considered pump depletion and used a medium with 3rd order succeptibility which is small compa…
Light with nonzero orbital angular momentum (OAM) or twisted light is promising for quantum communication applications such as OAM-entangled photonic qubits. There exist photonic OAM to photonic spin angular momentum (SAM), as well as photonic SAM to electronic SAM interfaces but not any direct photonic OAM-electronic SAM (flying to stationary) media converter within a single device. Here, we propose a scheme which converts photonic OAM to electronic SAM and vice versa within a single nanophotonic device. We employed a photonic crystal nanocavity with an embedded quantum dot (QD) which confine…
Reducing a set of diverse bulk-optic-based optical components to a single ultrathin and compact element that enables the same complex functionality has become an emerging research area, propelling further integration and miniaturization in photonics. In this work, we establish a versatile metasurface platform based on gap-surface plasmon meta-atoms enabling efficient linear-polarization conversion along with the complete phase control over reflected fields. Capitalizing on the meta-atom design, multifunctional metamirrors involving linear-polarization conversion and focusing are experimentally…
The enhancement of Er$^{3+}$-based up-conversion for photovoltaics in multilayer porous silicon photonic structures is considered theoretically and experimentally. Transfer matrix simulations are used to assess the increased photonic density of states that results from the slowing of energy propagation at the short-wavelength edge of one-dimensional photonic band gaps. An indirect calculation of Er$^{3+}$ absorption enhancement within slow-light modes is then used to illustrate an increase in absorption over the bulk value: the effective absorption coefficient is shown to increase by more than…
An undoped double quantum well (DQW) was driven with a terahertz (THz) electric field of frequency ω_{THz} polarized in the growth direction, while simultaneously illuminated with a near-infrared (NIR) laser at frequency ω_{NIR}. The intensity of NIR upconverted sidebands ω_{sideband}=ω_{NIR} + ω_{THz} was maximized when a dc voltage applied in the growth direction tuned the excitonic states into resonance with both the THz and NIR fields. There was no detectable upconversion far from resonance. The results demonstrate the possibility of using gated DQW devices for all-optical wavelength shift…
While two-dimensional (2D) materials have intriguing second-order nonlinearities with ultrahigh coefficient and electrical tunability, their atomic layer thicknesses hinder explorations of other optical frequency-conversions (OFCs) than second harmonic generation (SHG) due to inefficient light-coupling and unachievable phase-matching. We report, by resonantly pumping a photonic crystal cavity integrated with a few-layer GaSe, it is possible to realize multiple second-order nonlinear processes in GaSe even with microwatts continuous wave pumps, including SHGs, sum-frequency generations (SFGs), …
A theoretical and experimental performance analysis of a Semiconductor Optical Amplifier - Mach-Zehnder Interferometer (SOA-MZI) photonic sampling mixer used as a frequency up-converter is presented employing Switching and Modulation architectures. An active mode-locked laser, generating 2 ps-width pulses at a repetition rate equal to 10 GHz, is used as a sampling source. An optical carrier intensity modulated by a sinusoidal signal at 1 GHz is up-converted to 9 GHz and 39 GHz. High Conversion Gains (CGs) of about 15 dB are demonstrated for the frequency conversion to 9 GHz using both architec…
Single-photon wave packets can carry quantum information between nodes of a quantum network. An important general operation in photon-based quantum information systems is blind reversal of a photon's temporal wave-packet envelope, that is, the ability to reverse an envelope without knowing the temporal state of the photon. We present an all-optical means for doing so, using nonlinear-optical frequency conversion driven by a short pump pulse. This scheme allows for quantum operations such as a temporal-mode parity sorter. We also verify that the scheme works for arbitrary states (not only singl…
Leveraging the quantum information processing ability of superconducting circuits and long-distance distribution ability of optical photons promises the realization of complex and large-scale quantum networks. In such a scheme, a coherent and efficient quantum transducer between superconducting and photonic circuits is critical. However, such quantum transducer is still challenging since the use of intermediate excitations in current schemes introduces extra noise and limits bandwidth. Here we realize direct and coherent transduction between superconducting and photonic circuits based on tripl…
Visible-wavelength very large-scale integration (VLSI) photonic circuits have potential to play important roles in quantum information and sensing technologies. The realization of scalable, high-speed, and low-loss photonic mesh circuits depends on reliable and well-engineered visible photonic components. Here we report a low-voltage optical phase shifter based on piezo-actuated mechanical cantilevers, fabricated on a CMOS compatible, 200 mm wafer-based visible photonics platform. We show linear phase and amplitude modulation with 6 V$_π$-cm in differential operation, -1.5 dB to -2 dB insertio…
Defect modes are investigated in a band gap of an electrically tunable one-dimensional photonic crystal infiltrated with a twisted-nematic liquid crystal (1D PC/TN). Their frequency shift and interference under applied voltage are studied both experimentally and theoretically. We deal with the case where the defect layer thickness is much larger than the wavelength (Mauguin condition). It is shown theoretically that the defect modes could have a complex structure with the elliptic polarization. Two series of polarized modes interact with each other and exhibit an avoided crossing phenomenon in…
The unique ring-shaped intensity patterns and helical phase fronts of optical vortices make them useful in many applications. Here we report for the first time efficient Raman frequency conversion between vortex modes in twisted hydrogen-filled single-ring hollow core photonic crystal fiber (SR-PCF). High fidelity transmission of optical vortices in untwisted SR-PCF becomes more and more difficult as the orbital angular momentum (OAM) order increases, due to scattering at structural imperfections in the fiber microstructure. In helically twisted SR-PCF, however, the degeneracy between left- an…
We demonstrate second harmonic generation in photonic crystal nanocavities fabricated in the semiconductor gallium phosphide. We observe second harmonic radiation at 750 nm with input powers of only nanowatts coupled to the cavity and conversion efficiency $P_{\rm out}/P_{\rm in, coupled}^2 = 430%/{\rm W}$. The large electronic band gap of GaP minimizes absorption loss, allowing efficient conversion. Our results are promising for integrated, low-power light sources and on-chip reduction of input power in other nonlinear processes.
Electrically actuated optomechanical resonators provide a route to quantum-coherent, bidirectional conversion of microwave and optical photons. Such devices could enable optical interconnection of quantum computers based on qubits operating at microwave frequencies. Here we present a novel platform for microwave-to-optical conversion comprising a photonic crystal cavity made of single-crystal, piezoelectric gallium phosphide integrated on pre-fabricated niobium circuits on an intrinsic silicon substrate. The devices exploit spatially extended, sideband-resolved mechanical breathing modes at $\…
Integrated nonlinear wavelength converters transfer optical energy from lasers or quantum emitters to other useful colors, but chromatic dispersion limits the range of achievable wavelength shifts. Moreover, because of geometric dispersion, fabrication tolerances reduce the accuracy with which devices produce specific target wavelengths. Here, we report nonlinear wavelength converters whose operation is not contingent on dispersion engineering; yet, the output wavelengths are controlled with high accuracy. In our scheme, coherent coupling between counter-propagating waves in a photonic crystal…
Single photon-level quantum frequency conversion has recently been demonstrated using silicon nitride microring resonators. The resonance enhancement offered by such systems enables high-efficiency translation of quantum states of light across wide frequency ranges at sub-watt pump powers. Using a quantum-mechanical Hamiltonian formalism, we present a detailed theoretical analysis of the conversion dynamics in these systems, and show that they are capable of converting single- and multi-photon quantum states. Analytic formulas for the conversion efficiency, spectral conversion probability dens…
