Directional optical microphones

Abstract

The invention provides a directional optical microphone, including a housing having an open wall portion closed by a membrane attached thereto, the membrane having an outer surface and an inner surface facing the inside of the housing; a first light waveguide accommodated within the housing, having an output end portion for transmitting light towards the inner surface of the membrane, and a second light waveguide having an input end portion for receiving light reflected from the inner surface; the output and input end portions being positioned in close proximity to, and in optical isolation from, each other, and at least one aperture made in a wall of the housing, the aperture having a cross-sectional area of not less than 1 mm2, for admitting sound waves into the housing to impinge on the inner surface of the membrane.

Dependencies are inferred from the claim text.