AN OPTICAL DETECTOR

摘要

An optical detector (1) acts as a modular detection unit. It may for example be mounted on a separate micro-fluidic device (2) for detection of species within a channel (3) of the device (2). The detector (1) has mounting lugs (4) for mounting on the micro-fluidic device (2) for exact registry with the channel (3). A substrate (15) is folded over at a flexible part (25) through 180° and, at the top, supports a vertical emitting laser device (16). The lower branch of the substrate (15) supports an integrated circuit photo-diode array sensor (17) having chip bumps (18). The substrate (15) also supports emitter drive circuitry (26) and detector circuitry (27). The sensor (17) is a silicon integrated circuit, having an array of integrated photo-diodes (17(a)) in a silicon wafer (17(b)). There is a vertical through-hole (17(c)) in the wafer, to act as a guide for incident radiation emitted by the emitter (16) (arrows IR). Because of the single folded-over substrate arrangement the emitter 16 can be particularly easily and accurately aligned with the guide aperture 17(c).