Reliable control of quantum information in matter-based qubits requires precisely applied external fields, and unaccounted-for spatial crosstalk of these fields between adjacent qubits leads to loss of fidelity. We report a CMOS foundry-produced microfabricated silicon nitride (Si3N4) optical waveguide for addressing a chain of eight unequally spaced trapped barium ions, with crosstalk compatible with scalable quantum information processing. The crosstalk-mitigation techniques incorporated into the chip design result in a reduction of the measured optical field by at least between adjacent waveguide outputs near 650 nm and similar behavior for devices designed for 493 nm and 585 nm. The waveguide outputs near 650 nm, along with a global laser near 493 nm, have been used to laser cool a chain of eight 138Ba+ ions, and a camera has imaged the resulting fluorescence at 493 nm.

Detecting nonclassical light is a central requirement for photonics-based quantum technologies. Unrivaled high efficiencies and low dark counts have positioned superconducting nanowire single-photon detectors (SNSPDs) as the leading detector technology for integrated photonic applications. However, a central challenge lies in their integration within photonic integrated circuits, regardless of material platform or surface topography. Here, we introduce a method based on transfer printing that overcomes these constraints and allows for the integration of SNSPDs onto arbitrary photonic substrates. With a kinetically controlled elastomer stamp, we transfer suspended SNSPDs onto commercially manufactured silicon and lithium niobate on insulator integrated photonic circuits. Focused ion beam metal deposition then wires the detectors to the circuits, thereby allowing us to monitor photon counts with >7% detection efficiencies. Our method eliminates detector integration bottlenecks and provides new venues for versatile, accessible, and scalable quantum information processors.

Controlling large-scale many-body quantum systems at the level of single photons and single atomic systems is a central goal in quantum information science and technology. Intensive research and development has propelled foundry-based silicon-on-insulator photonic integrated circuits to a leading platform for large-scale optical control with individual mode programmability. However, integrating atomic quantum systems with single-emitter tunability remains an open challenge. Here, we overcome this barrier through the hybrid integration of multiple InAs/InP microchiplets containing high-brightness infrared semiconductor quantum dot single photon emitters into advanced silicon-on-insulator photonic integrated circuits fabricated in a 300~mm foundry process. With this platform, we achieve single photon emission via resonance fluorescence and scalable emission wavelength tunability through an electrically controlled non-volatile memory. The combined control of photonic and quantum systems opens the door to programmable quantum information processors manufactured in leading semiconductor foundries.

AIM Photonics design enablement platforms supporting photonic integrated circuit design, interposer-based assembly, and design-for-test for a 300 mm CMOS-compatible silicon-photonics foundry are presented.

Photonic integrated circuits provide a scalable platform for photonics-based quantum technologies. However, integrating quantum emitters and electro-optic cavities within this platform remains an open challenge proving to be a major hurdle from implementing key functionalities for quantum photonics, such as single photon sources and nonlinearities. Here, we address this shortcoming with the hybrid integration of InAs/InP quantum dot emitters on foundry silicon photonics and the implementation of photonic crystal cavities in thin-film lithium niobate. Co-integrated on-chip electronics allow us to tune the emission properties of the quantum dots while enabling GHz-rate coherent modulation over photons trapped in the cavities, thus providing a new level of programmability over interactions between optical fields and atom-like systems in integrated circuits. Our results open the door to a new generation of quantum information processors that can be manufactured in leading semiconductor foundries.

We experimentally investigate optical modulation in thermally undercut microdisk modulators. Optical modulation is realized over a spectral range 6x wider than the resonator’s linewidth due to the enhancement of optically induced thermal nonlinearity.

We report a fully-packaged, on-chip multi-photon-pair source using spontaneous-four-wave-mixing (SFWM) in silicon waveguide spirals. Our source consists of four, two-centimeter long spiral waveguides that are pumped in parallel using a pulsed laser source. We detected a four-fold coincidence rate of 180 +/- 20Hz, corresponding to an on-chip coincidence rate of 908 +/- 42Hz.

We demonstrate low-loss aluminum nitride waveguides fabricated using a standard silicon photonics process flow in a CMOS foundry. The material’s wide transparency and χ(2) nonlinearity can extend silicon photonics to novel visible wavelength applications.

We introduce hybrid integrated telecom single-photon sources on a commercial foundry multilayer silicon photonic chip. We show above-band and resonant waveguide-coupled single-photon emission tunable via the DC Stark shift.

We demonstrate highly efficient vertical junction microdisk modulators with selective substrate undercut in a 300 mm CMOS foundry. The devices achieve record thermo-optic efficiency for sub-5 µm radius, enabling next-generation low-energy, highly-parallel DWDM links.

While the high index contrast between silicon and silicon dioxide in the silicon-on-insulator photonics platform permits unprecedented device density, it also leads to high sensitivity to fabrication variations. In silicon microring and microdisk resonator devices, fabrication variations can substantially change the target resonance wavelength. Silicon’s high thermo-optic coefficient allows for correction of these fabrication variations and stabilization of the device resonant wavelength through thermal tuning. Metal and doped silicon integrated heaters are commonly used to perform this tuning and have become an essential feature of silicon microring and microdisk modulators. Metal heaters are typically placed in a layer above the silicon devices, while doped silicon heaters are placed in the same silicon waveguide layer, adjacent to the devices. The advantage of doped silicon heaters over metal heaters is due to proximity of the heater to the optical device, leading to greater efficiencies. However, for active devices using p-n junctions such as modulators, parasitic junctions can form between the doped heater and the modulator junctions, resulting in highly unstable and substandard device performance. Here, we present a detailed simulation framework for heater design in resonant silicon microdisk modulators, supported by experimentally measured device performance, which emphasizes tuning efficiency while eliminating parasitic diode formation. Simulations were conducted in Ansys Lumerical HEAT, CHARGE, and MODE to model parasitic junction behavior between the heater and modulator, in addition to the heater’s thermal response and its effect on the resonant wavelength of the microdisk.

We present inverse-designed arrays of vertically-coupled, high-finesse, wavelength-scale photonic crystal cavities in a commercial foundry. Dynamically controlling each pixel with a high-speed (~100 MHz) μLED display enables efficient spatial light modulation with unprecedented spatiotemporal bandwidth.

We have demonstrated a packaged Silicon photon pair source. The spiral silicon waveguide source is 500 nm x 220 nm x 2 cm long and was packaged with input/output optical fibers enabling turn-key generation of photon pairs by connecting the input optical fiber to a telecommunication grade laser. In this work, we experimentally characterized the generation of bi-photons by spontaneous four-wave mixing in the Silicon waveguide. The insertion loss of the chip, after packaging, was measured to be approximately 15 dB (3 dB/facet, waveguide propagation loss of less than 1.5 dB/cm, 6 dB from splitters sequence). We investigated the phase matching of the source by wavelength tuning the 1 nm bandpass filters and found that the generated bi-photons have a half-bandwidth of 10 nm about the pump wavelength. We investigate pulse pumping using an actively mode-locked fiber laser with a 500 MHz repetition rate, pulse duration of approximately 30 ps and peak pulse power of 400 mW. Excitation of the pulsed source with a power of 1.4 mW through the chip generated 300 kHz coincidence rates after passing the chip’s output through a series of spectral bandpass filters (-1.4 db in channel 1 and -2.4 dB in channel 2 of filter loss and approximately 85 % efficiency of the detectors: inferred on-chip pair generation rate of 58 MHz). We also investigate two sources with 6 mW of continuous-wave pump power to generate 1550 nm bi-photons, generating 6.0 kHz coincidence rates (inferred on-chip pair generation rate of 2.3 MHz).

We present a thermally isolated phase shifter through undercutting the silicon waveguide and resistive heaters, yielding a low-power (Pπ= 1.2 mW) and low-crosstalk tunable Mach-Zehnder interferometer.

As computing resource demands continue to escalate in the face of big data, cloud-connectivity and the internet of things, it has become imperative to develop new low-power, scalable architectures. Neuromorphic photonics, or photonic neural networks, have become a feasible solution for the physical implementation of efficient algorithms directly on-chip. This application is primarily due to the linear nature of light and the scalability of silicon photonics, specifically leveraging the wide-scale complementary metal-oxide-semiconductor manufacturing infrastructure used to fabricate microelectronics chips. Current neuromorphic photonic implementations stem from two paradigms: wavelength coherent and incoherent. Here, we introduce a novel architecture that supports coherent and incoherent operation to increase the capability and capacity of photonic neural networks with a dramatic reduction in footprint compared to previous demonstrations. As a proof-of-principle, we experimentally demonstrate simple addition and subtraction operations on a foundry-fabricated silicon photonic chip. Additionally, we experimentally validate an on-chip network to predict the logical 2 bit gates AND, OR, and XOR to accuracies of 96.8%, 99%, and 98.5%, respectively. This architecture is compatible with highly wavelength parallel sources, enabling massively scalable photonic neural networks.

An electro-optic modulator operating at visible wavelengths is demonstrated with TFLNOI (Thin Film Lithium Niobate on Insulator) flip-chip bonded on a foundry fabricated SiN (Silicon Nitride) photonic integrated chip, achieving a π phase shift with VπL = 7.5V.

We design and demonstrate a high extinction ratio (ER) microring modulator. The modulator has a high ER of 27 dB across the wafer, and a measured ER of > 13.9 dB for modulation speeds up to 20 Gbps.

Harnessing the full complexity of optical fields requires the complete control of all degrees of freedom within a region of space and time—an open goal for present-day spatial light modulators, active metasurfaces and optical phased arrays. Here, we resolve this challenge with a programmable photonic crystal cavity array enabled by four key advances: (1) near-unity vertical coupling to high-finesse microcavities through inverse design; (2) scalable fabrication by optimized 300 mm full-wafer processing; (3) picometre-precision resonance alignment using automated, closed-loop ‘holographic trimming’; and (4) out-of-plane cavity control via a high-speed μLED array. Combining each, we demonstrate the near-complete spatiotemporal control of a 64 resonator, two-dimensional spatial light modulator with nanosecond- and femtojoule-order switching. Simultaneously operating wavelength-scale modes near the space–bandwidth and time–bandwidth limits, this work opens a new regime of programmability at the fundamental limits of multimode optical control.

We present a new architecture for performing learning-based tasks directly on an integrated photonic chip. We experimentally realize logical 2-bit gates AND, OR, and XOR to accuracies of 96.8%, 99%, and 98.5%, respectively.