摘要 |
An optical fiber structure having resonant characteristics useful for coupling to an optical transmission line for removing selected wavelengths of light energy includes a light guiding structure, such as an optical fiber waveguide, which conditionally operates as a resonant cavity responsive to resonance of at least one other resonant cavity. In one embodiment, an extrinisically defined or adscititious reflectance is formed in the waveguide segment by laterally coupling an etalon cavity to the waveguide segment. In another embodiment, the waveguide segment is coupled to one or more resonant loops to form a conditional resonant loop cavity which includes the other loops. The resonant wavelength spacing for the conditional cavity and its cooperating resonant cavity are made different from one another with only one wavelength coresonantly supported in both cavities. In operation, the structure is coupled to a multichannel optical transmission line for selectively removing a portion of the energy of a desired channel by resonating the desired wavelength in both the conditional cavity and its cooperating resonant cavity. Additionally, an active gain material can be provided in the conditional cavity and pumped by a pumping source to increase the gain of the desired wavelength. |