J.V. Collins

Passive alignment of second generation optoelectronic devices

This paper details how expanded-mode semiconductor devices and passive alignment techniques can be used to realize low-cost high-performance fiber grating laser and laser amplifier packages for future generations of optical telecommunication systems.

Tapered active layer laser device performance and its impact on low cost optoelectronics

75% coupling to cleaved single mode fibre has been obtained for a 1.55 /spl mu/m tapered active strained MQW layer device. A fully packaged component using precision laser die cleaving and a silicon micro machined substrate has produced a record 55% passive coupling.

The packaging of large spot-size optoelectronic devices

Lasers have been passively aligned to cleaved singlemode optical fibres on a silicon bench with coupling efficiencies of over 50%. This is the highest known reported result. Using the relaxed tolerances obtained from large spotsize lasers a very simple high performance laser package has also be produced. The combination of semiconductor device developments, silicon micromachining and novel packaging techniques has realised complicated optoelectronic modules which will give the technical performance and economic requirements needed for future optical telecommunication networks.

The packaging of large spot-size semiconductor optical amplifiers

By matching the emission spot size of the semiconductor device to that of a singlemode fibre the packaging processes become much simpler. Results from large spot semiconductor amplifiers which can be assembled in conventional or low cost passive configurations have been reported. These devices have both the performance and, in the passively aligned package the very low cost needed to dramatically affect the architecture of future telecommunication networks.

Hybrid integration of optical and electronic components on a silicon motherboard

We have demonstrated silicon motherboard transmitter and receiver modules with planar silica waveguide optical interconnects. In both modules the active optoelectronic components were passively aligned to the silica waveguides, and electronic circuitry was also hybrid integrated. We are now- developing motherboards which include an electrical interconnect layer formed directly on the silicon, in order to overcome the limitations encountered with bond-wires.

Practical multi-fibre array packaging technology

Most published data to date on fibre array alignment, especially for motherboard components, has been based on the use of silicon v-groove technology to position the fibres and this can give a fibre-to-fibre positional accuracy of a micron or so, assuming that is, that the fibre being used has a tight manufacturing tolerance of 0.51 /spl mu/m for both concentricity and diameter. Work at BT Labs has concentrated on the adaption of standard single device packaging technology for device arrays up to the 1x4 level, and the use of the MT (mechanically transferable) fibre connector for 1x4 devices.<<ETX>>

Hybrid integration of an optical processor on a LIGA motherboard

Over the past few years it has become increasingly clear that semiconductor laser amplifiers hold great promise for very high speed all-optical nonlinear processing applications. The small size of the semiconductor amplifier means that, in principle, it should be possible to not only switch at very high rates, but, if the dimensions of the overall device are small enough, to do this on a bit-by-it basis. For repetition rates of 10-100 GHz this demands dimensions of 3 cm down to 3 mm. Clearly, the latter demands a fully integrated approach. However, for dimensions of the order of 3 cm a hybrid technology using bulk optics is an attractive alternative. We investigate the feasibility of this approach by using the LIG(A) process to construct a micro-optic motherboard for the passive assembly of an optical processing system based on the Terahertz Asymmetric Demultiplexer (TOAD) configuration. A schematic representation of a TOAD as configured using an optical fibre loop is shown.

Preliminary results on the use of LIGA in an optoelectronics application

LIGA (German acronym of lithographie, galvanoformung (plating) and abformung (forming)) is a relatively new technology which offers a potential means of realising very accurate (sub-micron) and high aspect ratio structures. In this paper we show the application of the LIGA process to optoelectronic assembly applications.

A generic technology for low cost semiconductor optoelectronic devices

This paper details the latest results on the use of expanded mode semiconductor devices and passive alignment techniques to realise low cost high performance laser amplifier and fibre grating laser packages.