Luxtera and TSMC have jointly developed a new generation 100Gbps/λ-capable silicon photonics platform in a commercial 300 mm CMOS line. We present process details and the performance of the photonic device library.

The two-photon spectrum of photon pairs generated at room-temperature in optically-pumped silicon microrings was measured using tunable filters, InGaAs single-photon avalanche detectors and deconvolution, and an image-processing artifact-reduction algorithm is discussed.

We design a nonlinear waveguide for 2f-to-3f optical frequency conversion based on silicon nitride-lithium niobate and calculate high nonlinear conversion efficiencies of 898, 623, and 3169 %-W-1-cm(-2) for the processes discussed.

We demonstrate a photonic waveguide technology based on a two-material core, in which light is controllably and repeatedly transferred back and forth between sub-micron thickness crystalline layers of Si and LN bonded to one another, where the former is patterned and the latter is not. In this way, the foundry-based wafer-scale fabrication technology for silicon photonics can be leveraged to form lithium-niobate based integrated optical devices. Using two different guided modes and an adiabatic mode transition between them, we demonstrate a set of building blocks such as waveguides, bends, and couplers which can be used to route light underneath an unpatterned slab of LN, as well as outside the LN-bonded region, thus enabling complex and compact lightwave circuits in LN alongside Si photonics with fabrication ease and low cost.

Generation of photon pairs from compact, manufacturable, and inexpensive silicon (Si) photonic devices at room temperature may help develop practical applications of quantum photonics. An important characteristic of photon-pair generation is the two-photon joint spectral intensity, which describes the frequency correlations of the photon pair. Recent attempts to generate a factorizable photon-pair state suitable for heralding have used short optical pump pulses from mode-locked lasers, which are much more expensive and bigger table-top or rack-sized instruments compared with the Si microchip used for generating photon pairs, and thus dominate the cost and inhibit the miniaturization of the source. Here, we generate photon pairs from an Si microring resonator by using an electronic step-recovery diode to drive an electro-optic modulator which carves the pump light from a continuous-wave laser diode into pulses of the appropriate width, thus potentially eliminating the need for optical mode-locked lasers.

Microring resonators made from silicon are becoming a popular microscale device format for generating photon pairs at telecommunications wavelengths at room temperature.In compact devices with a footprint less than 5 × 10 -4 mm 2 , we demonstrate pair generation using only a few microwatts of average pump power.We discuss the role played by important parameters such as the loss, group-velocity dispersion and the ring-waveguide coupling coefficient in finding the optimum operating point for silicon microring pair generation.Silicon photonics can be fabricated using deep ultraviolet lithography wafer-scale fabrication processes, which is scalable and cost-effective.Such small devices and low pump power requirements, and the side-coupled waveguide geometry which uses an integrated waveguide, could be beneficial for future scaled-up architectures where many pair-generation devices are required on the same chip.

Silicon photonic microchips may be useful for compact, inexpensive, room-temperature optically pumped photon-pair sources, which unlike conventional photon-pair generators based on crystals or optical fibers, can be manufactured using CMOS-compatible processes on silicon wafers. It has been shown that photon pairs can be created in simple structures such as microring resonators at a rate of a few hundred kilohertz using less than a milliwatt of optical pump power, based on the process of spontaneous four-wave mixing. To create a practical photon-pair source, however, also requires some way of monitoring the device and aligning the pump wavelength when the temperature varies, since silicon resonators are highly sensitive to temperature. In fact, monitoring photodiodes are standard components in classical laser diodes, but the incorporation of germanium or InGaAs photodiodes would raise the cost and fabrication complexity. Here, we present a simple and effective all-electronic technique for finding the optimum operating point for the microring used to generate photon pairs, based on measuring the reverse-biased current in a silicon p-i-n junction diode fabricated across the waveguide that constitutes the silicon microring. We show that by monitoring the current, and using it to tune the pump laser wavelength, the photon-pair generation properties of the microring can be preserved over a temperature range of more than 30 °C.

We characterize the strength of entanglement corresponding to different Joint Spectral Intensities of telecommunications-wavelength photon pairs generated using spontaneous four-wave mixing in a diode-pumped compact CMOS-compatible silicon chip

Using two-photon (Franson) interferometry, we measure the entanglement of photon pairs generated from an optically-pumped silicon photonic device consisting of a few coupled microring resonators. The pair-source chip operates at room temperature, and the InGaAs single-photon avalanche detectors (SPADs) are thermo-electrically cooled to 234K. Such a device can be integrated with other components for practical entangled photon-pair generation at telecommunications wavelengths.

Silicon photonics has drawn a lot of attention over the last decades, mainly in telecom-related application fields where the nonlinear optical properties of silicon are ignored or minimized. However, silicon’s high χ(3) Kerr optical nonlinearity in sub-micron-scale high-confinement waveguides can enable significant improvements in traditional nonlinear devices, such as for wavelength conversion, and also enable some device applications in quantum optics or for quantum key distribution. In order to establish the viability of silicon photonics in practical applications, some big challenges are to improve the optical performance (e.g., optimize nonlinearity or minimize loss) and integration of optics with microelectronics. In this context, we discuss how electronic PIN diodes improve the performance of wavelength conversion in a microring resonator based four-wave mixing device, which achieves a continuous-wave four-wave mixing conversion efficiency of −21.3 dB at 100 mW pump power, with enough bandwidth for the wavelength conversion of a 10 Gbps signal. In the regime of quantum optics, we describe a coupled microring device that can serve as a tunable source of entangled photon pairs at telecommunications wavelengths, operating at room temperature with a low pump power requirement. By controlling either the optical pump wavelength, or the chip temperature, we show that the output bi-photon spectrum can be varied, with implications on the degree of frequency correlation of the generated quantum state.

Integrated optics devices for nonlinear optics may be made by using unpatterned thin films of a nonlinear crystal such as lithium niobate in conjunction with (for example, bonded to) an easily-patterned material such as silicon or silicon nitride which is commonly used in a silicon photonics platform. We propose and analyze a device for difference-frequency generation in a hybrid waveguide which uses the strongest nonlinear tensor coefficient without ion-exchanging, etching, or periodically-poling lithium niobate, which can considerably simplify the fabrication process.

Silicon photonic waveguides and resonators fabricated using CMOS-compatible processes can generate photon pairs at telecommunications wavelengths and at room temperature, with electrically controllable properties e.g., tunable frequency-bin entangled comb and tunable joint spectral intensity.

Directly modulated semiconductor lasers are widely used, compact light sources in optical communications. Semiconductors can also be used to generate nonclassical light; in fact, CMOS-compatible silicon chips can be used to generate pairs of single photons at room temperature. Unlike the classical laser, the photon-pair source requires control over a two-dimensional joint spectral intensity (JSI) and it is not possible to process the photons separately, as this could destroy the entanglement. Here we design a photon-pair source, consisting of planar lightwave components fabricated using CMOS-compatible lithography in silicon, which has the capability to vary the JSI. By controlling either the optical pump wavelength, or the temperature of the chip, we demonstrate the ability to select different JSIs, with a large variation in the Schmidt number. Such control can benefit high-dimensional communications where detector-timing constraints can be relaxed by realizing a large Schmidt number in a small frequency range.

To demonstrate control over the quantum spectrum of light, we tune the joint spectral intensity of photon pairs generated at telecommunications wavelengths using a low-power diode-pumped compact CMOS-compatible silicon chip at room temperature.

Within the ambitious quest for an electrically pumped version of the optical parametric oscillator (OPO), we demonstrate the first near-infrared integrated OPO in a direct gap semiconductor. This nonlinear device is based on a selectively oxidized GaAs/AlAs heterostructure, the same “AlOx” technology that is at the heart of VCSEL fabrication. The heterostructure and waveguide design allows for type-I form-birefringent phase matching, with a TM00 pump around 1 μm and TE00 signal and idler around 2 μm. Relying on the high non-resonant χ(2) of GaAs, relatively weak guided-wave optical losses, and monolithic SiO2/TiO2 dichroic Bragg mirrors, we observe a threshold of 210 mW at degeneracy in the continuous-wave regime, with a single-pass-pump doubly resonant scheme. Further improvement can be achieved by adopting a double-pump-pass scheme and, in a more fundamental way, by further optimizing the waveguide optical losses. The latter are induced by a not entirely mastered AlAs oxidation process and are of two distinct types: Rayleighlike scattering at signal and idler wavelength (α ≤ 1cm-1), due to the interface roughness between GaAs and AlOx layers; and absorption at pump wavelengths (α ≈ 3cm-1), due to volume defects in the GaAs layers adjacent to the aluminum oxide. This result marks a milestone for integrated nonlinear photonics and represents a significant step toward the goal of a broadly tunable coherent light source on chip.

We demonstrate the frequency doubling of a quantum cascade laser in a multilayered, partially oxidized GaAs/AlOx waveguide. Using the waveguide width to fulfill the phase-matching condition, the second harmonic is generated in the wavelength range between 2.2 and 2.4 μm, where not many semiconductor sources are commercially available to date. We discuss the impact of a few fabrication and experimental parameters on the conversion efficiency, an essential step toward the improvement and practical implementation of this proof-of-principle semiconductor microsystem.

We demonstrate the frequency doubling of a quantum cascade laser in a multilayered, partially oxidized GaAs/AlOx waveguide. Using the waveguide width to fulfill the phase-matching condition, the second harmonic is generated in the wavelength range between 2.2 and 2.4 μm, where not many semiconductor sources are commercially available to date. We discuss the impact of a few fabrication and experimental parameters on the conversion efficiency, an essential step toward the improvement and practical implementation of this proof-of-principle semiconductor microsystem.

We report on the observation of self-amplified parametric downconversion in a selectively oxidized AlGaAs cavity that was designed to perform as a guided-wave optical parametric oscillator in the near infrared. To date, two technological factors preclude such oscillation and are thoroughly investigated here: oxidation-induced optical propagation losses and the reflectivity of the waveguide resonator facets. The spectral study of the former has singled out two distinct mechanisms: scattering at the oxide interfaces and absorption by point defects in the oxide neighboring layers. Regarding the latter, dielectric mirrors have been designed and deposited on the ridge waveguide facets, with modal reflectivities of similar to 10% at pump wavelength and similar to 90% at signal/idler wavelengths. With respect to the case of a mirrorless waveguide, the monolithic cavity enabled a factor-2 enhancement of the conversion efficiency, indicating the close proximity of the oscillation threshold. (C) 2014 Optical Society of America

Photonics puts at stake a wide variety of applications, from applied fields of physics, such as ultrafast all-optical signal processing [1] or pollutant monitoring [2], to more fundamental ones, e.g. quantum information [3], and its convergence with electronics at chip-scale level is one of today’s great scientific and technological challenges. As a consequence, the full inte‐ gration of optoelectronics devices on existing developed platforms is expected to be the next technological leap, with major breakthroughs in telecommunications, industry and health. While the main building blocks of optical integrated circuitry have been reported in the standard SOI platform [4], coherent light sources still markedly lack to achieve this transi‐ tion of paradigm. To date, the hybrid conjunction of silicon photonics and direct-gap III-V compounds appears to be one of the most promising key technologies towards large-scale photonic integration and scalability [5]. In particular, such photonics platform could capital‐ ize advanced functionalities enabled by guided-wave quadratic nonlinear optics. Thus, the demonstration of the electrically pumped versions of an optical parametric oscillator (OPO) or of a telecom twin-photon source (TTPS) would have a great impact on applications re‐ quiring room-temperature operation and wide tunability.

Ce travail de these porte sur le developpement des savoir-faire technologiques necessaires a la realisation de sources parametriques integrees emettant dans l’infrarouge. Pour cela, les guides d’ondes birefringents AlGaAs/AlOx consideres, grâce a leur forte non linearite quadratique et a la maturite des techniques de fabrication, se revelent etre un choix pertinent. La fabrication et la caracterisation d’un convertisseur de frequence de ce type, concu pour la conversion parametrique descendante d’une pompe a 775 nm en paires de photons a 1550 nm, nous a permis de demontrer une efficacite de conversion normalisee de 1100 %W−1cm−2, une puissance de second harmonique de 0.3 mW, ainsi qu’une accordabilite de 570 nm. Bien qu’a l’etat de l’art des dispositifs integres AlGaAs, ces performances restent limitees par les pertes optiques induites par le processus d’oxydation. Afin d’etablir un lien entre les pertes de propagation et les proprietes physico-chimiques de l’AlOx, nous avons etudie leur comportement spectral. Deux mecanismes de pertes ont ete mis en evidence : un regime de diffusion a grande longueur d’onde, en accord avec un modele considerant les interfaces rugueuses de l’AlOx, et un regime d’absorption a faible longueur d’onde, attribue a la presence de defauts generes par la reaction d’oxydation. Un effort de developpement technologique visant a augmenter l’efficacite de nos echantillons a ete entrepris suivant deux axes : l’optimisation fine du procede d’oxydation et la mise en cavite optique des guides d’ondes. Les resultats obtenus sont tres encourageants pour la realisation de dispositifs non lineaires efficaces, et la demonstration d’un OPO integre en particulier.