Ilse Christiaens

Thin-film devices fabricated with benzocyclobutene adhesive wafer bonding

In this paper, we present and elaborate on die to wafer bonding technology with benzocyclobutene (BCB). This technology allows to fabricate a variety of reliable waferbonded components in a fairly simple way using only standard cleanroom equipment. We demonstrate the fabrication of passive devices such as microring resonators, as well as active components such as lasers and LEDs. We show good performance of these devices by presenting measurements of their characteristics. Furthermore, these devices were subjected to damp-heat testing, demonstrating the good quality of the BCB-bonding procedure. Finally, due to the low thermal conductivity of BCB, thermal management needs some attention. We present an analysis of the thermal problem and suggest a possible solution.

New widely tunable edge-emitting laser diodes at 1.55 μm developed in the European IST-project NEWTON

Widely tunable lasers are generally considered as the transmitters of future WDM optical communications. Electronically tunable edge-emitting laser diodes are of particular interest as they can switch the wavelength in tens of nanoseconds and thus offer great potential for new networking concepts such as optical packet or burst switching, label switching, bandwidth on demand, ... In this paper we discuss new concepts for such widely tunable laser diodes which are studied in the framework of the European IST project NEWTON (NEw Widely Tunable laser diodes for Optical Networks).

Grating-assisted resonant-cavity LEDs: toward thin film devices for heterogeneous integration

Design and fabrication of thin film GaAs Grating-Assisted Resonant-Cavity LEDs (GA-RCLED) emitting at 980 nm are reported. The devices are fabricated by gluing the sample and a transfer substrate with benzocyclobutene (BCB) and consequently thinning the sample. The design is optimised for a high extraction efficiency. The efficiency of substrate emitting planar RCLEDs is limited by leaky DBR modes. This quasi continuum of modes does not fall in the DBR stop band and is internally reflected at the semiconductor-air interface. Consequently, the leaky modes are absorbed in the substrate and are lost. The use of a thin film device can avoid this loss term. The laterally propagating mode can be recuperated by the use of a grating. The diffractive properties of the periodic grating can redirect the resonant guided mode to the extraction cone. The 2-D grating is defined on the surface of the thin film RCLED by means of holographic exposure. As the devices are thinned they are more compatible with wafer scale integration with electronic devices.

Integration of photonic functions in and with silicon

Silicon is gaining importance in photonic systems on a chip, either because of the importance of integrating photonic functions with electronic functions or because of the potential of silicon-based technology for photonics as such. In this paper, we discuss two distinct developments. The first is the development of nano-photonic integrated circuits based on photonic crystals or photonic wires. The second is the development of heterogeneously integrated active photonic components on top of silicon by means of wafer bonding.

InP-based PIC for an optical phased array antenna at 1.06 /spl mu/m

We have demonstrated the feasibility of a photonic integrated circuit for phase control at a wavelength of 1.06 /spl mu/m in an optical phased array telescope antenna system.