| 摘要 |
<p>A pressure-isolated Bragg grating temperature sensor includes an optical element (20, 600) which includes an optical fiber (10) having at least one Bragg grating (12) disposed therein which is encased within and fused to at least a portion of an inner glass capillary tube (20) and/or a large diameter waveguide grating (600) having a core and a wide cladding and having the grating (12) disposed therein, which is encased within an outer tube (40) to form a chamber (44). An extended portion (58) of the sensing element that has the grating (12) therein extends inwardly into the chamber (44) which allows the grating (12) to sense temperature changes but isolates the grating (12) from external pressure. An end tube (42) may be attached to the tube (40) and the fiber (10) fed therethrough to form the chamber (44) and a pass-through for the fiber (10). As the external pressure P increases, the outer tube (40) compresses or deflects, the sensing element (20, 600) moves closer to the end tube (42) and/or the outer tube (40) move toward each other. More than one grating or pair of gratings may be used and more than one fiber or optical core may be used. Also, at least a portion of the sensing element may be doped between a pair of gratings (150, 152), to form a temperature tuned laser or the grating (12) or gratings (150, 152) may be configured as a tunable DFB laser disposed in the sensing element.</p> |
