Patent ID: 7940446
Filing Date: 2011-05-10
Classification: G01J,G02B

Abstract:
1. A modulator for modulating an optical signal, the modulator comprising a spacing-controllable etalon comprising at least one sprung micro-mirror suspended over a substrate, at least one insulating stop located between the micro-mirror and the substrate and further comprising a control circuit arranged, in operation, to apply a voltage between the micro-mirror and substrate whereby to displace the micro-mirror from its equilibrium position towards the substrate into a snap-down state in which the sprung micro-mirror is retained in contact with the at least one insulating stop and in which, responsive to a control signal, the control circuit is arranged to release or not release the micro-mirror at successive times calculated to maximise or minimise transmission through the etalon of incident light in successive pulses received from a remote laser source, whereby to modulate the transmitted pulses.