Patent ID: 8724935

Claim:
An optical device comprising: a first optical fibre portion having a first sensing region and further regions between which the first sensing region is positioned; a first Bragg grating incorporated in a first sensing region; a second optical fibre portion having a second sensing region and further regions between which the second sensing region is positioned; a second Bragg grating incorporated in a second sensing region; at least one member to which the first and second optical fibre portions are attached at the first and second sensing regions; a moveable wall portion coupled to the first Bragg grating so that a movement of the moveable wall portion causes a force that effects a change in strain of the first Bragg grating and thereby effects a change in an optical period of the first Bragg grating whereby the optical device is arranged for pressure sensing; and wherein the first and second sensing regions are positioned at opposite sides of an area defined between the first and second sensing regions and spaced apart from each other by a first distance and wherein adjacent further regions are spaced apart by a second distance that is smaller than the first distance.