Koen Vandeputte

First demonstration of highly reflective and highly polarization selective diffraction gratings (GIRO-gratings) for long-wavelength VCSELs

We present experimental results on surface relief gratings in GaAs and InP with high reflectivity (>85%) and polarization selectivity to normal incidence from the semiconductor side. The potential for polarization stabilization with a reduced mirror complexity for long-wavelength VCSELs is discussed.

Direct MT(TM)-compatible connectorisation of VCSEL and LED-arrays to plastic optical fiber ribbon for low cost parallel datalinks

For the realisation of MT compatible direct connectorised modules, a PMMA-based interconnection scheme, using index-alignment is developed. Plastic pieces are accurately positioned with respect to the chips and then fixed with epoxy, following an index-alignment strategy. Alignment accuracies in the range of 5 to 10 /spl mu/m have been achieved, which is sufficient to have good coupling efficiencies in view of the relaxed alignment tolerances when coupling to large core POF (120/125 /spl mu/m). The chips are assembled in commercially available packages, which are then mounted on PCB boards. First coupling measurements on fully assembled modules, using a red (670 nm) 1/spl times/8 VCSEL-array and a 1/spl times/8 RC-LED (Resonant Cavity LED, 980 nm), are successfully carried out.

Demonstration of multi-wavelength laser with a gain-clamped output amplifier

We proposed a new approach to reduce the thermal crosstalk problem and to avoid crosstalk in the output amplifier of a multi-wavelength laser based on the gain-clamping principle. The device was realised, using the hybrid coupling technique, and the gain-clamping was experimentally verified.

An integrated optical add/drop multiplexer in InP based on elliptic couplers and Bragg grating reflector

The wavelength add/drop multiplexer (ADM) is one of the key components for dense wavelength division multiplexing (DWDM) systems. To realise this function, a number of schemes have been proposed and tested based on planar waveguide circuits or optical fibers, such as the planar waveguide based grating-folded directional coupler ADM, fiber based ADMs using Mach-Zehnder interferometer structure and photoimprinted Bragg gratings and so on. We proposed a new add/drop scheme based on elliptic beam collimators and Bragg gratings realised in InP. In this paper, we will report the device design, fabrication and the preliminary experimental results.

A parallel optical link for intra- and inter-rack interconnections

This paper presents a re-configurable parallel optical link aiming to solve interconnection problems for the next generation of broadband switching systems in mature technologies at a low cost. The channel re-configuration and interconnections at intra-subrack level are achieved using a flexible or flexible-rigid optical backpanel fabricated in glass optical fiber wiring. Above intra-subrack level, fiber ribbon cables are used to cover a span from a few meters to hundreds of meters. This technology is demonstrated in a multi-channel system, by placing E/O modules in circuit boards and in an application card which is located on the back side of the electrical backpanel. The system employs single mode glass optical fibers, terminated in MT ferrules and MOP connectors. In the presence of a fiber ribbon cable of 204 meters, the demonstrator is able to operate at 622 Mbit/s, with a BER<7/spl times/10/sup -5/.