We report the fabrication of a three dimensional branched ZnO/Si heterojunction nanowire array by two-step, wafer-scale, low-cost, solution etching/growth method and its use as photoelectrode in photoelectrochemical cell for high efficiency solar powered water splitting. Specifically, we demonstrate that offers improved light absorption, increased photocurrent generation due to effective charge separation Si backbones ZnO branching, enhanced gas evolution kinetics because dramatically...

Using a compact (0.03 mm(2)) silicon-photonic bias-free thermo-optic cross-bar switch, we demonstrate microsecond-scale switching of twenty wavelength channels C-band wavelength-division multiplexed optical ring network, each carrying 10 Gbit/second data concurrently, with 15 mW electrical power consumption (no temperature control required). A convenient pulsed driving scheme is demonstrated and eye patterns bit-error rate measurements are shown. An algorithm developed to measure the...

Using the measured transmission spectrum of a waveguide-coupled silicon microring, we develop an algorithm for determining wavelength dependencies (i.e., dispersions) coupling coefficients and loss ring. Our analysis reconstructs without use Lorentzian fitting, covers 15 free spectral ranges (FSR), was performed from <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${\sim}{1520}$</tex></formula> to...

Silicon-on-insulator rib waveguides with passive loss of -0.74 dB/cm and free-carrier lifetime reduction via reverse biased p-i-n diodes are used to show efficient continuous wave four-wave mixing 2 × in required pump power for comparably high conversion efficiency -8.2 dB, similar best reports. A -13.4 dB is also subsequently achieved using 20 μm radius micro-ring resonators at significantly reduced power.

This paper presents a novel design algorithm for filter bank structure that is suitable photonic integrated circuits. The proposed entirely based on the principle of loss-exhibiting allpass filtering, which behavior naturally observed in variety microscale optical components. setup and mathematical optimization system explored detail from signal processing perspective, an convex nonlinear techniques subsequently presented. methodologically utilizes otherwise-undesirable effect waveguide loss...

Despite being an integral part of the vision quantum Internet, Earth-to-satellite (uplink) communications have been considered more challenging than their satellite-to-Earth (downlink) counterparts due to severe channel-loss fluctuations (fading) induced by atmospheric turbulence. The question how address negative impact fading on remains largely open issue. In this work, we explore feasibility exploiting spatial diversity as a means mitigation in Continuous-Variable (CV) quantum-classical...

The next generation of space-based networks for communications, sensing, and navigation will contain optical clocks embedded within satellites. To fully realize the capabilities such clocks, high-precision clock synchronization across be necessary. Current experiments have shown potential classical frequency combs to synchronize remote over free space. However, these are restricted in precision standard quantum limit. Quantum combs, however, which exhibit properties as squeezing...

The Continuous-Variable (CV) quantum state of light allows for the teleportation a Discrete-Variable (DV) photonic qubit. Such an operation is useful in realm hybrid networks. However, it known that DV qubit via Gaussian CV resource channel severely limited under loss, with fidelity beyond classical limit unattainable losses exceeding small threshold 0.5 dB. In this work, we present new non-deterministic protocol combines modified form Bell State Measurement accommodates DV-qubit up to...

We design and demonstrate a compact silicon photonic chip (1.30 mm x 0.52 mm) that integrates electrically-tunable 4-channel add, drop power control functionalities for 24x10 Gbit/s WDM data-center network with low consumption.

A two-part silicon photonic variable optical attenuator is demonstrated in a compact footprint which can provide high extinction ratio at wavelengths between 1520 nm and 1620 nm. The device was made by following the conventional p-i-n waveguide section high-extinction-ratio second-order microring filter section. rings additional on-off contrast utilizing thermal resonance shift, harvested heat dissipated current injection junction. We derive discuss simple thermal-resistance model...

The photonic Temporal Mode (TM) represents a possible candidate for the delivery of viable multidimensional quantum communications. However, relative to other information carriers such as Orbital Angular Momentum (OAM), TM has received less attention. Moreover, in context emerging internet and satellite-based communications, no In this work, we remedy situation by considering traversal through satellite-to-Earth channel single photons encoded space. Our results indicate that anticipated...

Highly-accurate time synchronization between satellites provides for a plethora of fundamental physics investigations as well providing range enhanced-engineering applications. However, current state-of-the-art techniques in space are limited by the Standard Quantum Limit (SQL), thereby limiting progress. Squeezed light, however, offers pathway to overcome SQL — an example 'quantum advantage' offered non-classical states light. Here we investigate, first time, practicality achieving such...

Precision navigation and timing, very-long-baseline interferometry, next-generation communication, sensing, tests of fundamental physics all require a highly synchronized network clocks. With the advance highly-accurate optical atomic clocks, precision requirements for synchronization are reaching limits classical (i.e. standard quantum limit, SQL). Efficiently overcoming SQL to reach Heisenberg limit can be achieved via use squeezed or entangled light. Although approaches well understood in...

Abstract In typical laser communications classical information is encoded by modulating the amplitude of beam and measured via direct detection. We add a layer security using quantum physics to this standard scheme, applicable free-space channels. consider simultaneous classical-quantum communication scheme where in usual way as fluctuations sub-Poissonian noise-floor. For secret key generation, we continuous-variable distribution protocol (CVQKD) Gaussian ensemble squeezed states Under...

Classical free-space optical (FSO) communication promises massive data throughput rates relative to traditional wireless technologies - an attractive outcome now being pursued in the context of satellite-ground, inter-satellite and deep-space communications. The question we investigate here is: how can minimally alter classical FSO systems, both infrastructure energy input, provide some element quantum coexisting with communications? To address this question, explore additional Gaussian...

The next generation of space-based networks will contain optical clocks embedded within satellites. To fully realize the capabilities such clocks, high-precision clock synchronization across be necessary. Current experiments have shown potential for classical frequency combs to synchronize remote over free-space. However, these are restricted in precision standard quantum limit. Quantum combs, however, which exhibit properties as squeezing and entanglement, provide pathways going beyond...

Abstract Quantum super-resolution involves resolving two sources below the Rayleigh limit using quantum optics. Such a technique would allow high-precision inter-satellite positioning and tracking on communication navigation constellations. Due to size, weight power constraints typical of low-earth-orbit (LEO) satellites, simple solution is often preferred. Here, we show that balanced homodyne detection (BHD) setup shaped single-mode local oscillator can achieve despite photonic losses. We...

We present a lowpass design algorithm targeted specifically for photonic implementation. Allpass filter based systems are ideal realizations because they can be naturally realized using variety of nanoscale dielectric components. The allpass filters system is particularly noteworthy example advanced usages sub-structures. While the structure excellent implementation components, practical considerations about its suboptimal performance yet to considered. Realistic optical subject...

Using a compact (0.03 mm^2) silicon photonic thermo-optic switch with five cascaded thermo-topic phase-shifters, we demonstrate low insertion loss, power, microsecond-scale cross-bar switching of twenty wavelength channels, each carrying 10 Gbit/second data concurrently.

The effect of the thickness barrier layers between quantum dots (QD) in a vertically stacked QD array has been studied using both simulation and experimental techniques. Silvaco ATLAS is used to model how QW affects onset confined electron wavefunction overlap. This indicates that thicknesses less than 8 nm provide miniband formation wells. P-i-n devices with strain balanced QD/barrier superlattice embedded i-region were grown epitaxially varying thicknesses. Electroluminescence measurements...