Abstract: A support device, for the monitor and keyboard of a personal computer, enables the personal computer to be used by a person lying on a bed. The support device has a support body adapted for mounting over a person on a bed. The support body has first and second shelves. Each shelf is inclined forwardly and downwardly towards the user, and the second shelf can be inclined at a greater angle. The monitor and keyboard are mounted on the first and second shelf respectively. Retaining members are provided for holding the monitor and keyboard on the shelves. The support body can be mounted on the bed itself, or on a base running on wheels beneath the bed.

Abstract: A double heterostructure semiconductor laser having the configuration of its optical cavity arranged to impose a constraint on the lasing filament as the spatial distribution of the lasing filament changes from that occuring at the start of the lasing regime, so that the optical flux emitted by the laser has self-saturating properties. This protects the laser from catastrophic facet erosion and enables a simpler control circuit to be used to drive this laser when it is used as a light source for an optical communications system.