With the increasing use of optical fibre in both the telecommunications and home networking areas, the packaging and
alignment of various optoelectronic devices has never been more
critical. In particular coupling of Plastic Optical Fibre (POF) to
detectors has become an important area of research. Most off-the-shelf POF has a core diameter of 980 micron, while a typical photodiode may have an active area diameter of 50 micron. Hence without some kind of physical alignment losses may become unmanageable. This paper describes efforts to couple Plastic
Optical Fibres to an avalanche photodiode (APD) array.
An imaging POF fibre-bundle is used to connect to the array in a
low cost versatile manner. An array of up to ten fibres is used
to form the bundle. Mechanical guide systems both on the
substrate of the chip and on the package housing itself are used
to align each individual fibre to a corresponding photodiode. The
results from several focusing techniques are presented to overcome
coupling losses encountered while focusing the beam from the POF
onto the smaller detector active area. A multi fibre connector is
used to connect other instruments at the opposite end of the fibre
bundle. The primary application of this technology will enable the
use of arrays of photon counting detectors in astronomy.