Nortel Networks Corporation

Northern Telecom Limited

John Kenneth Severn

A rear light entry photodetector array chip is secured face-down with solder on to the front face of a ceramic submount provided with electrically conductive vias. A frame-shaped mass of solder seals the chip to the submount to provide a hermetic enclosure protecting sensitive semiconductor surface areas of the photodetector chip array where electric fields are liable to be present in the vicinity of a pn or metal/semiconductor junction. The place of the photodetector array can be taken by a similar construction array of semiconductor light-emissive opto-electronic devices, such as VCSELs, or a mixed array including emitters and detectors.

Semiconductor opto-electronic device packaging

A rear light entry photodetector chip is secured face-down with solder on to the front face of a ceramic submount provided with a pair of electrically conductive vias. A frame-shaped mass of solder seals the chip to the submount to provide a hermetic enclosure protecting sensitive semiconductor surface areas of the photodetector chip where electric fields are liable to be present in the vicinity of a pn or metal/semiconductor junction.

Semiconductor photodetector packaging

An optical arrangement for full duplexed PON outstation transceivers (single fibber operation) which improves control of optical output power during marshalling by reducing the light level at which closed loop control can be used. The arrangement uses a beam-expanded region incorporating a bulk-optics beam-splitter with a reflective field stop that will tap a higher proportion of the basestation transmitter power when it is operating below lasing threshold and hence has a larger beam size than when operating above threshold.

Optical transmitter output monitoring tap

A TDMA basestation transmitter has a monolithic concentric arrangement of two monitor photodiodes (14a, 14b) for use in power output regulation both in marshalling procedure and in normal data traffic situations where there are two distinct speed and sensitivity requirements to be satisfied at different times.

Growing community of inventors

Totnes, United Kingdom

John Kenneth Severn