FEEDBACK STABILIZED MULTI-MODE LASER AND METHOD OF STABILIZING A MULTI-MODE LASER

摘要

The laser assembly (10) comprises a multimode laser (12) having at least one output and operating at a given wavelength. It also includes a double-clad optical fiber (20) having a free end (22) coupled to the output of the laser (12). The optical fiber (20) comprises a core (24) in registry with the output of the laser (12), a multimode inner cladding (26) surrounding the core (24), and an outer cladding (28) surrounding the inner cladding (26), the outer cladding (28) being provided to contain light in the inner cladding (26). A fiber Bragg grating (30) is written in the core (24) of the fiber (20) at a given distance from the free end (22) thereof. The Bragg grating (30) has a reflection spectrum within the gain spectrum of the laser (12). In use, it generates a sufficient feedback and stabilizes the laser (12) at the reflection spectrum of the Bragg grating (30). This provides a low cost laser assembly that is simple, suitable for volume manufacturing and small in size.