COMPRESSION-TUNED BRAGG GRATING AND LASER

摘要

A compression-tuned Bragg grating includes a tunable optical element 20, 600 which includes either an optical fiber (10) having at least one Bragg gratin g (12) impressed therein encased within and fused to at least a portion of a glass capillary tube (20) or a large diameter waveguide grating (600) having a core and a wide cladding. Light (14) is incident on the grating (12) and lig ht (16) is reflected at a reflection wavelength .lambda.1. The tunable element 20, 600 is axially compressed which causes a shift in the reflection wavelength of the grating (12) without buckling the element. The shape of th e element may be other geometries (e.g., a "dogbone" shape) and/or more than o ne grating or pair of gratings may be used and more than one fiber (10) or core (612) may be used. At least a portion of the element may be doped between a pair of gratings (150, 152), to form a compression-tuned laser or the gratin g (12) or gratings (150, 152) may be constructed as a tunable DFB laser. Also, the element (20) may have an inner tapered region (22) or tapered (or fluted ) sections (27). The compression may be done by a PZT, stepper motor or other actuator or fluid pressure.