This PDF file contains the front matter associated with SPIE Proceedings Volume 12334, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

Monolithic cointegration of electronics and photonics in the same silicon die is expected to enable a new realm of high-performance electro-optical systems for telecommunications, automotive, datacenter and sensing applications. As an alternative to integrating photonic devices into well-established microelectronic technologies, in this paper we report on the integration of CMOS electronic circuits in a commercial Silicon Photonics technology. Transistors with a threshold voltage of 1.84V, a gain factor of 4 μA/V² and an Early voltage of 35V have been obtained by using the same masks as the photonic layer, without any additional technological steps in a truly zero-change paradigm. The paper reports a first application of this novel approach, showing time-multiplexed control of a 16-to-1 optical router enabled by an on-chip analog multiplexer.

New machine learning algorithms such as deep neural networks and the availability of large datasets have created a large drive towards new types of hardware capable of executing these algorithms with higher energy-efficiency. Recently, silicon photonics has emerged as a promising hardware platform for neuromorphic computing due to its inherent capability to process linear and non-linear operations and transmit a high bandwidth of data in parallel. At Hewlett Packard Labs, an energy-efficient dense-wavelength division multiplexing (DWDM) silicon photonics platform has been developed as the underlying foundation for innovative neuromorphic computing architectures. The latest research on our silicon photonic neuromorphic platform will be presented and discussed.

Cavity optomechanics offers significant reduction in noise and drift for inertial sensing devices by providing high signal-to-noise displacement sensing. Strong coupling between mechanical motion and optical resonances such as whispering gallery mode resonances has been shown to detect displacements at the femtometer scale. By using a photonic integrated circuit (PIC) ring resonator to detect the motion of a micro-electro-mechanical systems (MEMS) structure as it moves within the optical evanescent field, sensitivities 100-10,000x better than existing low-cost inertial sensors can be achieved. To design optimised accelerometers and vibratory gyroscopes, accurate finite element simulations of the PIC resonators are required to match the sophistication of MEMS modelling. We describe comparisons between frequency domain methods and 2D finite-difference time-domain (FDTD) methods for silicon ring resonators. As a demonstration of our working principle, we show experimental data where we measure the motion of a mechanical cantilever. We also characterise the thermo-optic induced shifting of the ring resonator resonance by measuring this effect, showing good agreement with FDTD simulations.

The ability to precisely measure the displacement between two elements, e.g. a mask and a substrate or a beam and optical elements, is fundamental to many precision experiments and processes. Yet typical optical displacement sensors struggle to go significantly below the diffraction limit. Here we combine advances in our understanding of directional scattering from nanoparticles with silicon photonic waveguides to demonstrate a displacement sensor with deep subwavelength accuracy. Depending on the level of integration and waveguide geometry used we achieve a spatial resolution between 5 − 7 nm, equivalent to approximately λ/200 − λ/300.

High-speed (upwards of 10⁵ coordinates s^-1) and long-range (~10 m) absolute distance measurement applications based on frequency scanning interferometry (FSI) generate very high modulation frequencies (typically >100 GHz) due to the laser frequency sweep rate and the large imbalance between the reference and object arms. Such systems are currently impractical due to the extremely high cost associated with sampling at these signal frequencies. Adaptive delay lines (ADLs) were recently proposed as a solution to balance the interferometer and therefore reduce sampling rate requirements by a factor of 2^N, where N is the number of switches in the ADL [1, 2]. The technique has been successfully demonstrated in the lab using bulk optics and optical fiber configurations, and further reduction in size and cost will increase the breadth of metrology applications that can be addressed. Silicon photonics constitute an effective platform to miniaturize ADLs to chip-scale, simplifying instrument manufacture and providing a more robust configuration compared to bulk-optics and fiber-based solutions. We discuss the design and fabrication of chip-scale ADLs on a silicon on insulator (SOI) photonics platform, using optical switches based on heaters, multi-mode interferometer (MMI) couplers and Mach-Zehnder interferometers (MZI). We also establish the heater voltages of 4 switches in series, required to switch the optical path in the reference arm, a necessary step to use the device for FSI range measurements.

Four-wave mixing (FWM) is a well-known technique to achieve all-optical control wavelength conversion. We propose a well-designed silicon nano-waveguide based on silicon-on-insulator (SOI) to achieve FWM conversion. Particularly, the original signal light continuously sweeps along the C band, and the generated idler light is correspondingly sweeping as the original signal is swept. The wavelengths of the idler and signal lights are symmetric with respect to the pump light wavelength. Simulation and experimental results of the FWM conversion properties are well-matched. With the pump light filtered out, a dual-frequency continuously sweeping laser source is achieved, which could be applied in dual-frequency scanning interferometry to eliminate dynamic errors in practical use.

We performed numerical simulation and fabrication of a compact and sensitive high-resolution spectrometer, by superimposing controlled disorder on a photonic crystal. This simultaneously creates an in-plane speckle and suppresses out-of-plane scattering. We perform two- dimensional and three- dimensional numerical simulations to demonstrate reduced out-of-plane scattering and enhanced throughput in such disorder-enhanced photonic crystal structures compared to completely disorder structures without any compromise on resolution.

We review our work on integrated lasers for optical communications. An InP-based multilayer stack containing Al-based quantum wells with optical gain in the telecom window is bonded onto a silicon-on-insulator wafer with patterned photonic circuits and cavities. Ring-based widely tunable lasers and narrow linewidth DFB lasers are demonstrated.

The amount of data processed by information and communications technology (ICT) equipment has significantly increased in recent years. As the power consumed by each board and rack continues to increase, the study of the immersion cooling technique with high cooling capacity has become increasingly widespread. We have developed an optical transceiver called “IOCore^M” based on Si photonics technology. In this paper, we report the results of the evaluation of the immersion cooling of IOCore.