Transfer printing for heterogeneous silicon PICs

Photonic integrated circuits (PICs), implementing optical functions such as light generation, modulation, routing and detection on a single chip, are emerging as a powerful platform to realize miniaturized optical systems. These chips find applications in various fields, ranging from high-speed optical transceivers to disposable biosensors, LiDARs for detection and ranging, spectroscopic analytical sensors, etc. Silicon photonics is the field that is using silicon fabrication technologies, developed over the last decades for advanced electronic integrated circuits, to realize PI Cs. Using this approach advanced PICs can be realized on 200 mm or 300 mm wafers in high volume and at low cost. On the silicon photonics platform many device structures are readily available: Si or SiN waveguides, micro-heaters for tuning/switching, Si or Ge based modulators and photodetectors. However, other optical functions such as light generation require the integration of III-V semiconductors on the silicon wafers. This can be realized using different approaches ranging from hybrid assembly over die-towafer bonding to monolithic integration. Every approach has its advantages and disadvantages. An interesting approach that we are developing is the use of microtransfer- printing technology for the integration of III-V semiconductor devices on a silicon photonic wafer, which is a scalable and minimally-invasive approach

Programmable photonics : an opportunity for an accessible large-volume PIC ecosystem

We look at the opportunities presented by the new concepts of generic programmable photonic integrated circuits (PIC) to deploy photonics on a larger scale. Programmable PICs consist of waveguide meshes of tunable couplers and phase shifters that can be reconfigured in software to define diverse functions and arbitrary connectivity between the input and output ports. Off-the-shelf programmable PICs can dramatically shorten the development time and deployment costs of new photonic products, as they bypass the design-fabrication cycle of a custom PIC. These chips, which actually consist of an entire technology stack of photonics, electronics packaging and software, can potentially be manufactured cheaper and in larger volumes than application-specific PICs. We look into the technology requirements of these generic programmable PICs and discuss the economy of scale. Finally, we make a qualitative analysis of the possible application spaces where generic programmable PICs can play an enabling role, especially to companies who do not have an in-depth background in PIC technology

Ultrafast optical ranging using microresonator soliton frequency combs

Light detection and ranging (LIDAR) is critical to many fields in science and industry. Over the last decade, optical frequency combs were shown to offer unique advantages in optical ranging, in particular when it comes to fast distance acquisition with high accuracy. However, current comb-based concepts are not suited for emerging high-volume applications such as drone navigation or autonomous driving. These applications critically rely on LIDAR systems that are not only accurate and fast, but also compact, robust, and amenable to cost-efficient mass-production. Here we show that integrated dissipative Kerr-soliton (DKS) comb sources provide a route to chip-scale LIDAR systems that combine sub-wavelength accuracy and unprecedented acquisition speed with the opportunity to exploit advanced photonic integration concepts for wafer-scale mass production. In our experiments, we use a pair of free-running DKS combs, each providing more than 100 carriers for massively parallel synthetic-wavelength interferometry. We demonstrate dual-comb distance measurements with record-low Allan deviations down to 12 nm at averaging times of 14 $\mu$s as well as ultrafast ranging at unprecedented measurement rates of up to 100 MHz. We prove the viability of our technique by sampling the naturally scattering surface of air-gun projectiles flying at 150 m/s (Mach 0.47). Combining integrated dual-comb LIDAR engines with chip-scale nanophotonic phased arrays, the approach could allow widespread use of compact ultrafast ranging systems in emerging mass applications.Comment: 9 pages, 3 figures, Supplementary information is attached in 'Ancillary files

III-V-on-silicon photonic integrated circuits for communication and sensing applications

We review the integration of III-V semiconductors on silicon photonic integrated circuits as a way of realizing fully integrated silicon photonic transceivers and short-wave infrared spectroscopic sensors

Photonic integration enabling new multiplexing concepts in optical board-to-board and rack-to-rack interconnects

New broadband applications are causing the datacenters to proliferate, raising the bar for higher interconnection speeds. So far, optical board-to-board and rack-to-rack interconnects relied primarily on low-cost commodity optical components assembled in a single package. Although this concept proved successful in the first generations of optical-interconnect modules, scalability is a daunting issue as signaling rates extend beyond 25 Gb/s. In this paper we present our work towards the development of two technology platforms for migration beyond Infiniband enhanced data rate (EDR), introducing new concepts in board-to-board and rack-to-rack interconnects. The first platform is developed in the framework of MIRAGE European project and relies on proven VCSEL technology, exploiting the inherent cost, yield, reliability and power consumption advantages of VCSELs. Wavelength multiplexing, PAM-4 modulation and multi-core fiber (MCF) multiplexing are introduced by combining VCSELs with integrated Si and glass photonics as well as BiCMOS electronics. An in-plane MCF-to-SOI interface is demonstrated, allowing coupling from the MCF cores to 340x400 nm Si waveguides. Development of a low-power VCSEL driver with integrated feed-forward equalizer is reported, allowing PAM-4 modulation of a bandwidth-limited VCSEL beyond 25 Gbaud. The second platform, developed within the frames of the European project PHOXTROT, considers the use of modulation formats of increased complexity in the context of optical interconnects. Powered by the evolution of DSP technology and towards an integration path between inter and intra datacenter traffic, this platform investigates optical interconnection system concepts capable to support 16QAM 40GBd data traffic, exploiting the advancements of silicon and polymer technologies

Foundry technology and services for si photonics

We discuss the progress in development and offering of silicon photonic integration platforms based on 200mm and 300mm wafer technologies. Devices have capability for developing high-speed datacommunication, but are also used for life science applications

Ultra-efficient frequency comb generation in AlGaAs-on-insulator microresonators

Recent advances in nonlinear optics have revolutionized integrated photonics, providing on-chip solutions to a wide range of new applications. Currently, state of the art integrated nonlinear photonic devices are mainly based on dielectric material platforms, such as Si₃N₄ and SiO₂. While semiconductor materials feature much higher nonlinear coefficients and convenience in active integration, they have suffered from high waveguide losses that prevent the realization of efficient nonlinear processes on-chip. Here, we challenge this status quo and demonstrate a low loss AlGaAs-on-insulator platform with anomalous dispersion and quality (Q) factors beyond 1.5 × 10⁶. Such a high quality factor, combined with high nonlinear coefficient and small mode volume, enabled us to demonstrate a Kerr frequency comb threshold of only ∼36 µW in a resonator with a 1 THz free spectral range, ∼100 times lower compared to that in previous semiconductor platforms. Moreover, combs with broad spans (>250 nm) have been generated with a pump power of ∼300 µW, which is lower than the threshold power of state-of the-art dielectric micro combs. A soliton-step transition has also been observed for the first time in an AlGaAs resonator