We present a SOI ring based sensor read-out system. The novelty of the architecture lies in the capability to sense the shifts of multiple peaks simultaneously with an integrated AWG spectrometer.

No abstract

Nanophotonic waveguides and components are promising for use in the large-scale integration of photonic circuits. Coupling light between nanophotonic waveguides and a single-mode fiber is an important problem and many different solutions have been proposed and demonstrated in recent years. In this paper, we discuss a grating coupler approach. Grating couplers can be placed anywhere on a circuit and can easily be integrated. We have experimentally demonstrated >30% coupling efficiency with a 1 dB bandwidth of 40 nm on standard wafers. Theoretically, the coupling efficiency can be improved to >90% using an optimized grating design and layer stack. The fabrication of the couplers in silicon-on-insulator and in indium phosphide membranes is also discussed.

The growing maturity of integrated photonic technology makes it possible to build increasingly large and complex photonic circuits on the surface of a chip. Today, most of these circuits are designed for a specific application. However, the increase in complexity creates an opportunity for a generation of photonic circuits that can be programmed in software for a wide variety of functions through a mesh of on-chip waveguides, tunable beam couplers and optical phase shifters. Here we discuss the state of this emerging technology, not just the recent developments in photonic building blocks and circuit architectures, but also the higher levels in the technology stack for the electronic control and programming strategies. We also cover the various possible applications in linear matrix operations, quantum information processing and microwave photonics and examine how these generic chips can accelerate the development of future photonic circuits by providing a higher-level platform for prototyping novel optical functionalities without the need for custom chip fabrication.

We show the real-space observation of fast and slow pulses propagating inside a photonic crystal waveguide by time-resolved near-field scanning optical microscopy. Local phase and group velocities of modes are measured. For a specific optical frequency we observe a localized pattern associated with a flat band in the dispersion diagram. During at least 3 ps, movement of this field is hardly discernible: its group velocity would be at most c=1000. The huge trapping times without the use of a cavity reveal new perspectives for dispersion and time control within photonic crystals.