MULTIPLEXER HAVING ASE SUPPRESSION

摘要

Consistent with the present disclosure, optical filters are provided in a reconfigurable optical add-drop multiplexer (ROADM). In one example, groups of optical signals are amplified by corresponding erbium-doped fiber amplifiers (EDFAs) and supplied to each optical filter, which has a passband that includes the wavelengths associated with the received optical signal group. Light at wavelengths outside the passband of each optical filter, such as amplified stimulated emission (ASE) light generated by a respective EDFA, is significantly attenuated. Each optical signal group, after such amplification and filtering may then be switched and combined in a multicast switch before being directed toward a desired optical communication path. When, for example, first and second optical signal groups are combined, however, the first optical signal group is accompanied by little or no ASE light at the second optical signal group wavelengths. In addition, the second optical signal group is not accompanied by significant ASE light at the first optical signal group wavelengths. Accordingly, the first and second optical signal groups have less noise than would otherwise be present in the absence of the optical filters, and bit error rates associated with the optical signal groups are reduced.

主权项

1. An apparatus, comprising:
a first plurality of optical sources, each of which providing a corresponding one of a first plurality of optical signals, each of which having a corresponding one of a first plurality of wavelengths; a second plurality of optical sources, each of which providing a second plurality of optical signals, each of which having a corresponding one of a second plurality of wavelengths; a first optical amplifier that receives the first plurality of optical signals; a second optical amplifier that receives the second plurality of optical signals, the first optical amplifier generating first amplified stimulated emission (ASE) over a first range of wavelengths, and the second optical amplifier generating second ASE over a second range of wavelengths, the first plurality of optical signals being within the second range of wavelengths and the second plurality of optical signals being within the first range of wavelengths; a first filter that attenuates the first ASE and a second filter that attenuates the second ASE; and an optical combiner that receives the first plurality of optical signals from the first optical amplifier and the second plurality of optical signals from the second optical amplifier and combines the first and second pluralities of optical signals onto an output.