| 摘要 |
<p>A cladding-pumped optical fiber laser comprises a semiconductor laser or semiconductor laser array as the pumping power source emitting laser beams to a double-clad optical fiber through an optical system, the optical system may be a coupler or a collimator and a coupler. The core of the double-clad fiber is made from active element(s) doped glass. The inner cladding with a polygonlike cross-section shape surrounds the core and can reduce local modes therein. The ratio of the cross-section area of the inner cladding and that of the core is less than 200. The refractive index of the outer cladding surrounding the inner cladding is less than that of the inner cladding. This structure of the double-clad fiber in the invention can avoid the local modes, and thus can achieve a high laser gain by a short fiber. So it improves the efficiency and cuts down the cost. It can be applied to an erbium doped glass fiber amplifier or other three-level lasers or conversion lasers.</p> |
