A silicon photonic based transmitter and receiver chipset for 4x106Gb/s 400 GBASE-DR4 data rates is presented. Each channel of the transmitter chip reaches high extinction ratio and optical modulation amplitude (OMA) with a low TDECQ penalty in full compliance with the IEEE standard. The receiver chips possess high responsivity with low polarization dependent loss. The use of discrete III-V arrayed components hybridized onto the silicon platform and passive alignment of single-mode fibers provides a low-cost, compact and scalable solution extendable to even higher aggregate rates and channel count.

We report for the first time, wavelength filters with reduced thermal sensitivity, based on a combination of crystalline silicon and hydrogenated amorphous silicon (a-Si:H) waveguides, integrated on the same silicon on an insulator wafer through a Complementary Metal Oxide Semiconductor (CMOS) compatible process flow. To demonstrate the concept, we design and fabricate Mach Zehnder Interferometers (MZIs) and Arrayed Waveguide Gratings (AWGs) based on this approach, and we measure thermal drift <1[pm/degrees K] in MZIs and <10 [pm/degrees K] in AWGs at C band. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

We propose a ‘TSV-free’ solution to create three-dimensional (3D) silicon photonic (SiPh) components and interconnects based on phase matching. The evanescent coupling between interlevel optical stacks is comprehensively studied and leveraged to achieve flexible light control and realize hetero-stack communication in a monolithic SiPh platform. Various 3D functional photonic components, such as polarizers, polarization splitters and electro-absorption modulators are proposed and investigated. The TSV-free 3D optical interconnect provides a promising path towards low-cost, high-density SiPh chips for both monolithic and hybrid platforms, and potentially enables applications in a wide variety of fields such as LiDAR, artificial intelligence and optical biosensors.

A comprehensive set of SiN building blocks was demonstrated on a monolithic SiPh platform. Low-loss SiN waveguides (<0.35dB/cm), Si-SiN transitions (0.026dB), efficient polarization splitters/rotators, and compact ring WDM filters were realized at O-band.

A beam shaping approach has been implemented to realize high-performance waveguide crossings based on cosine tapers. Devices with a compact footprint of 4.7µm×4.7µm were fabricated on the GLOBALFOUNDRIES 45 nm monolithic silicon photonics platform (45 CLO technology). Fabricated devices are found to be nearly wavelength independent (±0.035dB for 1260nm≤λ≤1360nm) with low insertion loss (∼0.2dB) and crosstalk (-35dB). The measured response of the devices is consistent with the three-dimensional finite-difference time-domain simulation results. The design stability is validated by measuring the device insertion loss on eight chips, which is found to be 0.197±0.017dB at the designed center wavelength of 1310 nm.

We leverage phase-matching between front-end-of-line (FEOL)/middle-of-line (MOL) and back-end-of-line (BEOL) stacks for flexible light control in a monolithic Si photonics platform. The efficient vertical coupling/decoupling enables novel devices with unique functions.

A beam shaping approach has been implemented to realize high-performance waveguide crossings based on cosine tapers. Devices with a compact footprint of 4.7 µm × 4.7 µm are implemented on a GLOBALFOUNDRIES monolithic silicon photonics platform. Fabricated devices are found to be nearly wavelength-independent (± 0.035 dB for 1260 nm ≤ λ ≤ 1360 nm) with low insertion loss (~ 0.2 dB) and crosstalk (< -35 dB). The measured response of the devices is consistent with simulation results obtained by 3D FDTD computations. The design stability is confirmed by measuring the device insertion loss over nine chips, which is found to be 0.197 ± 0.017 dB at the designed center wavelength of 1310 nm.

We propose a scheme for generating frequency-correlated two-photon states via Spontaneous Parametric Down Conversion in periodically poled nonlinear integrated-optic waveguides. A method to differentiate such states from traditional frequency anti-correlated photon-pair sources is discussed.

The asymmetric poling in a titanium diffused periodically poled lithium niobate waveguide mitigates phase distortions associated with strong chirping. It broadens significantly the entangled source bandwidth while preserving a high visibility of quantum interferometric sensing.

Broadband entangled photons enable quantum interferometry, a technique for ultra-high resolution measurement of polarization mode dispersion [1,2]. We present designs and preliminary results from a broadband entangled photon source in periodically poled lithium niobate waveguides.

We present a new approach to engineering broadband sources of entangled photon pairs for quantum interferometry. The source is based on quasi-phase-matched spontaneous parametric down conversion in a titanium diffused periodically poled lithium niobate waveguide with a strongly-chirped poling period. The proposed non-standard asymmetric poling mitigates phase distortions associated with the process of chirping. Asymmetric poling significantly broadens the entangled source bandwidth while preserving high visibility quantum interferometric sensing.

Recent studies in quantum biology suggest that quantum mechanics help us to explore quantum processes in biological system. Here, we demonstrate generation of photon pairs through spontaneous four-wave mixing process in naturally occurring fluorescent proteins. We develop a general empirical method for analyzing the relative strength of nonlinear optical interaction processes in five different organic fluorophores. Our results indicate that the generation of photon pairs in green fluorescent proteins is subject to less background noises than in other fluorophores, leading to a coincidence-to-accidental ratio ~145. As such proteins can be genetically engineered and fused to many biological cells, our experiment enables a new platform for quantum information processing in a biological environment such as biomimetic quantum networks and quantum sensors.

We demonstrate single-photon level Quantum Frequency Conversion using quasi-phase matched Ti:LiNbO3 waveguides. The potential of such devices for higher dimensional encoding using temporal qdits and quantum optical arbitrary waveform generation is discussed.

We demonstrate generation of correlated photon pairs in naturally occurring Green Fluorescent Protein through the process of nondegenerate four-wave mixing. We obtain high purity photon pairs with a maximum coincidence to accidental ratio of ~70.

Highly nonlinear solid-state systems are discussed as solutions for the generation of phase entangled coherent states. Such states are necessary for many quantum optical information applications including a newly proposed quantum key distribution protocol.

Photon pairs sources based on nonlinear optical techniques are essential components in modern quantum optical systems. We present here a naturally occurring biological source of photon pairs—Green Fluorescent Protein (GFP)—obtained by a non-degenerate four-wave mixing (FWM).

We present the measurement of chi((3)) nonlinearity of Green Fluorescent Protein. The nonlinear index is n(2) = 10(-19)m(2)/W, opening the possibility of using genetically engineerable and naturally occuring proteins in cells as a source of four wave mixing experiments. (C) 2013 Optical Society of America

We present an integrated source of polarization entangled photon pairs in the telecom regime, which is based on type II-phasematched parametric down-conversion (PDC) in a Ti-indiffused waveguide in periodically poled lithium niobate. The domain grating - consisting of an interlaced bi-periodic structure - is engineered to provide simultaneous phase-matching of two PDC processes, and enables the direct generation of non-degenerate, polarization entangled photon pairs with a brightness of B = 7 × 10(3) pairs/(s×mW×GHz). The spatial separation of the photon pairs is accomplished by a fiber-optical multiplexer facilitating a high compactness of the overall source. Visibilities exceeding 95 % and a violation of the Bell inequality with S = 2.57±0.06 could be demonstrated.

A novel source of polarization entangled photon pairs has been developed based on spontaneous parametric down conversion (SPDC) in a periodically poled Ti:LiNbO3 waveguide. The domain structure consists of interlaced domains with two periodicities designed for type II quasi-phase-matching. Design issues as well as experimental results on second harmonic and SPDC characterization and entanglement measurements are reported. Keywords-SPDC; PPLN; entanglement; interlaced

In this paper we present a compact source of narrow-band energy-time entangled photon pairs in the telecom regime based on a Ti-indiffused Periodically Poled Lithium Niobate (PPLN) waveguide resonator, i.e. a waveguide with end-face dielectric multi-layer mirrors. This is a monolithic doubly resonant Optical Parametric Oscillator (OPO) far below threshold, which generates photon pairs by Spontaneous Parametric Down Conversion (SPDC) at around 1560nm with a 117MHz (0.91 pm)- bandwidth. A coherence time of 2.7 ns is estimated by a time correlation measurement and a high quality of the entangled states is confirmed by a Bell-type experiment. Since highly coherent energy-time entangled photon pairs in the telecom regime are suitable for long distance transmission and manipulation, this source is well suited to the requirements of quantum communication.