Qinetiq Limited

Kernforschungszentrum Karlsruhe Gmbh

Stanley D Smith

Timothy Ashley

John Graham Crowder

Falk Mikosch

Volker P Manheim

An infrared light emitting diode arrangement comprising an infrared light emitting diode which emits positive luminescence when forward biased and emits negative luminescence when reverse biased. The diode is driven by an alternating forward and reverse bias input so that the difference in output power between the positive luminescence and the negative luminescence of the light emitting diode is stabilised with respect to temperature. The infrared light emitting diode arrangement has particular application as a source in gas sensors and reduces or eliminates temperature control requirements for infrared light emitting diode sources.

Infrared light emitting diodes

A switch matrix which comprises non-linear optical (e.g. bistable) elements each consisting of an optically active layer applied to a substrate. The surface of the substrate has a microstructure composed of pillars each of which functions as a switch element and has at least one optically active layer. The pillar structure prevents interaction due to thermal contact and diffusion of charge carriers across the optically active layer and the substrate. The lithographic-galvanic (LIGA) process described is suited to the mass production of these structured substrates my moulding plastics. Both transparent and opaque substrates with high aspect ratios and adequate stability can be advantageously manufactured in this way.

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Edinburgh, United Kingdom

Stanley D Smith