L. Zimmermann

CWDM Transmitter Module Based on Hybrid Integration

A simple concept for hybrid integration and packaging of III/V active devices in a multipurpose optical platform is introduced. The board could be used as a coarse wavelength-division multiplexing transmitter with four lasers or as a receiver with photodiodes, respectively. The assembly ensures ample heat dissipation, so the laser performance does not suffer after the packaging

Facet preparation of SOI waveguides by etching and cleaving compared to dicing and polishing

We compared two different techniques of facet preparation of silicon-on-insulator (SOI) waveguides: The conventional by dicing and polishing and our proposed by dry etching the facets and cleaving along anisotropically etched cleaving grooves.

Mach-Zehnder interferometer (MZI) with more than 20 dB extinction ratio on silicon-on-insulator

We have fabricated an MZI with more than 20 dB extinction ratio on SOI serving for the high demands of differential phase shift keying (DPSK) receivers with the capability of fast thermo-optic tuneability.

Low Loss Star Coupler Concept for AWGs in Rib Waveguide Technology

We introduce a new concept for a tapered transition between waveguides and a free propagation region (FPR) for rib waveguide technology. The optical field is pressed downwards to the lower part of the guiding layer by tapering off the waveguide. The subsequent FPR is also etched down to the lower part of the guiding layer, which results in an adiabatic transition from the waveguide to the slab. Arrayed waveguide gratings, designed with this technique, were fabricated in silicon-on-insulator and showed a reduction in insertion loss of about 2.5 dB

A new and simple concept for self-aligned hybrid integration in silicon on insulator (SOI)

A concept for a SOI motherboard is introduced. AuSn solder technology is used for hybrid integration. The device adjustment on the board is realised by passive self-alignment. First results on fabricated boards are very encouraging.

SOI Delay Interferometer with Tuned Polarization Dependent Wavelength Shift for 40 Gbit/s DPSK Demodulation

An SOI delay interferometer (DI) manufactured in 4 mum rib waveguide technology with tuned polarization dependent wavelength (PDWL) shift is presented. CW device performance & DPSK demodulation functionality in a 40 Gbits testbed are demonstrated.

Study of reactive ion etched (RIE) facets of silicon- on-insulator (SOI) rip waveguides

In our study we compare the quality of dry etched rip waveguide facets to facets prepared by a conventional polishing technique. Linear SOI waveguide arrays were fabricated on BESOI (bonded and etched-back SOI) material with a silicon top-layer of H = 4 /spl mu/m. We used standard contact lithography for patterning and a commercial RIE system for waveguide and facet etching. We studied different process flows (facet-first and rip-first), different masking materials and loading effects on the wafer. The surface of the facets was characterized by high resolution scanning electron microscopy (SEM). The additional coupling loss introduced by the process flow and by the etching conditions as well as the impact of the two on uniformity of the waveguide transmission were quantified by means of fiber-to-fiber optical measurements (at 1.55 /spl mu/m).

Concept for an Alternative Solder-Free Flip-Chip Technique on SOI using Black-Silicon

Black-silicon regions are defined on an SOI board and covered with an adhesion layer. The contacts of to be mounted devices are pushed towards these regions, to establish a mechanical, electrical, and thermal contact

CWDM Transmitter Board based on SOI

A CWDM transmitter board based on SOI is demonstrated. Active III/V components are integrated using Au/Sn solder technology and passive alignment. Precise mounting of lasers on the board is necessary to ensure low coupling losses