| 摘要 |
The disclosed article comprises a semiconductor laser (typically a multi-segment DBR laser) and feedback means for controlling the laser wavelength. The wavelength reference element in the feedback means advantageously is an optical fiber comprising an in-line refractive index grating (21). Such gratings frequently have a transmission spectrum that exhibits subsidiary lobes, in addition to the desired main lobe, potentially compromising the "cold-start" ability of prior art systems. This and other drawbacks of prior art systems exemplarily are overcome by apparatus that comprises a feedback loop that comprises means for causing a current IB to flow to the "Bragg" section of a multi-segment DBR laser such that the wavelength of the laser output (11) is a function of IB, and that further comprises means (25, 17, 16) for changing the temperature of the laser in response to a change in the wavelength of the laser. Use of a wavelength reference element that has a relatively wide primary minimum facilitates cold starting. Exemplarily, the disclosed article is a wavelength division multiplexed (WDM) optical fiber communication system. <IMAGE> |
