US 8,526,813 B2 · Optical switch with power equalization

Abstract

An optical intensity control system for use with an optical switch providing individual signal paths between input and output ports. The system has a optical splitters connectable to output multiplexers of the switch and also has variable optical intensity controllers (VOICs) for insertion into the individual signal paths. The VOICs individually control the intensity of optical signals present in the signal paths in accordance with intensity control signals. An equalizer is connected to the splitters and to the VOICs, for producing an estimate of the optical power of each individual switched optical signal and generating the intensity control signals. The equalizer is adapted to controllably isolate individual switched optical signals. In this way, individual and independent control of the power on each optical channel is provided, wavelength-dependent losses introduced by all the devices in the switch including the WDM devices at the output of the switch are accounted for and one optical coupler is required for each output optical fiber. Coarse equalization may be provided for each multiplexed optical signal either at the switch input or output, permitting a reduction in the dynamic range over which the VOICs inside the switch are required to operate.

Claims20

Dependent claims

An optical switch system, comprising:

at least one optical input port;
at least one optical output port;
an optical switch coupled between the at least one optical input port and the at least one optical output port, the optical switch being adapted to optically couple a selected input port to a selected output port to configure an optical path through the optical switch system;
an optical coupler in the optical path, the optical coupler being adapted to divert a portion of an optical signal on the optical path;
an optical channel power estimator optically coupled to the optical coupler to receive the diverted portion of the optical signal, wherein the optical channel power estimator is adapted to estimate optical power in an optical channel carried by the optical signal based on the diverted portion of the optical signal and to output a control signal indicative of the estimated optical power;
a variable optical intensity controller in the optical path, the variable optical intensity controller being coupled to the optical channel power estimator to receive the control signal and being adapted, in response to the control signal, to adjust an optical intensity of an optical signal on the optical path.

3 more elements

Dependencies are inferred from the claim text.

Optical switch with power equalization

Life of this patent

Optical switch with power equalization

Life of this patent

Abstract

Claims20