| 摘要 |
<p>An apparatus and a method for separating a light of a first wavelength μ1 from a second wavelength μ2, where μ1<μ2, in a waveguide such as an optical fiber is described. The apparatus includes a core (12) surrounded by a depressed cladding (16), which itself is surrounded by a secondary cladding (18). The core cross-section, the depressed cladding cross-section, the secondary cladding cross-section, and the refractive indices of the core, the depressed cladding and the secondary cladding are selected to produce a fundamental mode cutoff wavelength μc such that μ1<μc<μ2, and produce a high loss at the secondary wavelength μ2. The apparatus can be used as a filter, and amplifier, a laser, or in a nonlinear optical switch.</p> |
