Interferometric measurement with crosstalk suppression

摘要

An interferometric measurement system suppresses cross talk between optical waveguides used to measure one or more parameters. A first interferometric measurement channel coupled to a first waveguide, and a second interferometric measurement channel coupled to a second waveguide. At least one of the channels includes a reference light path in addition to the first and second waveguides. A reference path optical delay is associated with the reference light path, a first optical delay is associated with the input portion of at least one of the first and second interferometric measurement channels, and a second optical delay is associated with an output portion of the one interferometric measurement channel. A value of the first optical delay and a value the second optical delay are chosen to suppress crosstalk associated with the other of the first and second interferometric measurement channels in the one interferometric measurement channel over a predetermined length of the first waveguide. Signals corresponding to the reference light path and the first and second interferometric measurement channels are processed to measure one or more parameters.

主权项

1. An interferometric measurement system for suppressing cross talk between optical waveguides, comprising:
a first interferometric measurement channel coupled to a first waveguide; a second interferometric measurement channel coupled to a second waveguide; at least one of the channels including a reference light path in addition to the first and second waveguides; a first optical delay of one of an input portion and an output portion of at least one of the first and second interferometric measurement channels and a second optical delay of the other of the input portion and the output portion of the other interferometric measurement channel, a value of the first optical delay and a value of the second optical delay chosen to suppress crosstalk associated with the other of the first and second interferometric measurement channels in the one interferometric measurement channel over a predetermined length of the first waveguide; and processing circuitry configured to process signals corresponding to the reference light path and the first and second interferometric measurement channels to measure one or more parameters, wherein the processing circuitry is configured to use the first and second optical delays to shift the crosstalk to a time period sufficiently different from a measurement time period associated with the predetermined length.