'Aurora'-a time domain based meta-algorithm for the rapid simulation and design of complex optical circuits

A new simulation tool called ‘Aurora’, specifically developed to efficiently simulate highly complex optical devices such as OADMs and Routers based on (higher order)microring resonators, is presented. The meta-simulation algorithm used by Aurora creates a framework in which many different simulation algorithms can be properly combined rather than providing a simulation algorithm itself. The calculations of this program use a simple scheme based in the time domain from which the frequency response can easily be derived. Simulation results of a 4-port OADM and waveguide gratings show excellent agreement when compared to experimentally obtained measurement data and conventional simulation methods

Silicon oxynitride based photonics

Silicon oxynitride is a very attractive material for integrated optics. Besides possessing excellent optical properties it can be deposited with refractive indices varying over a wide range by tuning the material composition. In this contribution we will summarize the key properties of this material class and discuss several application examples. Preliminary results on novel processes, which will lead to largely reduced hydrogen incorporation and enable reflow of SiON material, are being presented

Thermal wavelength-selective switch based on micro-ring resonators

A thermally driven wavelength-selective switch, based on integrated-optic micro-ring resonators is described. This configuration allows high ON/OFF ratios combined with small dimensions. Measurements of the thermal behaviour of a single resonator confirm the switching capability

Thermally Tuneable, Wide FSR Switch based on Micro-ring Resonators

A thermally tuneable, wide FSR switch, based on integrated-optic micro-ring resonators is described. This wavelength-selective switch allows high ON/OFF ratios combined with small dimensions. Furthermore allows the structure for a wide Free Spectral Range, since multiple resonators are used. This switch can be used in WDM filter arrays for a transceiver in an access network. Measurements of the thermal behaviour of a single resonator confirm the switching capability of the switch

Self Phase Modulation and Stimulated Raman Scattering due to High Power Femtosecond Pulse Propagation in Silicon-on-Insulator Waveguides.

Self Phase Modulation (SPM) and Stimulated Raman Scattering (SRS) in silicon waveguides have been observed and will be discussed theoretically using a modified Nonlinear Schrödinger Equation. The high optical peak powers needed for the experiments were obtained by coupling sub-picosecond (200fs) transform limited pulses with a spectral width of 12nm into a single mode silicon waveguide. Spectral broadening up to 50nm has been observed due to Self Phase Modulation. An intensity increase of the idler spectrum around 1650nm at the expense of the 1550nm pump signal has been observed as function of pump power, indicating the presence of Stimulated Raman Scattering

Integrated Optical add-drop multiplexer using thermally tunable microring resonators

We present a four channel optical add-drop multiplexer based on vertically coupled microring resonators fabricated in Si3N4/SiO2. The device with a Manhattan-like geometry has a footprint of 0.25 mm2 and can find application in metro-networks. The individual micro-resonators have a 50 μm radius and are thermally tunable over a 4 nm range. The maximum power consumption per ring is 0.5 W. Measurements show that each microring has a bandwidth >10 Gbit and can be thermally tuned in less than 1 ms. The measured on-off resonance in the drop ports of each micro-resonator is 10 dB

Densely integrated microring resonator based photonic devices for use in access networks

Two reconfigurable optical add-drop multiplexers, operating in the second or third telecom window, as well as a 1x4x4 reconfigurable λ-router operating in the second telecom window, are demonstrated. The devices have a footprint less than 2 mm2 and are based on thermally tunable vertically coupled microring resonators fabricated in Si3N4/SiO2

AL 3 (BH 261): a new globular cluster in the Galaxy

AL~3 (BH 261), previously classified as a faint open cluster candidate, is shown to be a new globular cluster in the Milky Way, by means of B, V and I Color-Magnitude Diagrams. The main feature of AL~3 is a prominent blue extended Horizontal Branch. Its Color-Magnitude Diagrams match those of the intermediate metallicity cluster M~5. The cluster is projected in a rich bulge field, also contaminated by the disk main sequence. The globular cluster is located in the Galactic bulge at a distance from the Sun d$_{\odot}$ = 6.0$\pm$0.5 kpc. The reddening is E(B-V)=0.36$\pm$0.03 and the metallicity is estimated to be [Fe/H] $\approx$ -1.3$\pm$0.25. AL~3 is probably one of the least massive globular clusters of the Galaxy.Comment: 6 figures. Astrophysical Journal Letters, in pres

Propagation of short lightpulses in microring resonators

The propagation of short lightpulses in waveguiding structures with optical feedback, in our case optical microringresonators, has been studied theoretically and experimentally. It appears that, dependent on the measurement set-up, ballistic transport or interference in the time domain of fs and ps laser pulses can be observed. The experiments are analyzed in terms of characteristic time scales of the source, the waveguide device and the detector arrangement and are related to Heisenberg's uncertainty principle