Single-ended measurement of the spectral transmission response of an optical device under test
AssigneeEXFO Inc.
InventorsYves BRETON, Hongxin CHEN, Vincent CHOUINARD
Life of this patent
Estimating the term…
Abstract
There is provided a method for measuring the spectral transmission response of a DUT using a multi-wavelength Optical Time Domain Reflectometer (OTDR) which allows performing OTDR measurements across a spectral range of interest. The OTDR targets a single reflective OTDR event along the OTDR trace, e.g., a mirror, a non-angled polished (UPC) connector or any other reflective surface located at the remote end of the DUT, which reflectance peak in combination with a reference measurement allows to perform single-end measurements of the transmission response. The process is repeated at various wavelengths to obtain a spectral transmission response of the DUT.
Claims20
A method for measuring the spectral transmission response of an optical device under test, the method comprising:
- performing a plurality of OTDR acquisitions from a proximal end of the device under test for a corresponding plurality of mutually-different wavelengths, wherein each OTDR acquisition is performed by propagating in the device under test, a pulsed test signal and detecting a corresponding return light signal from the device under test representing backscattered and reflected light as a function of distance in the device under test;
- for each of the OTDR acquisitions, extracting a value of a reflection level of a reflective peak associated with a reflective surface at a remote end of the optical device under test;
- and
- calculating values of a spectral transmission response associated with said device from the values of reflection level of the reflective peak as a function of said wavelengths, in combination with a reference measurement associated with a reference reflector.
A test system for measuring the spectral transmission response of an optical device under test, the OTDR system comprising:
- an OTDR acquisition device connectable toward a proximal end of the device under test for performing a plurality of OTDR acquisitions for a corresponding plurality of mutually-different wavelengths, wherein each OTDR acquisition is performed by propagating in the device under test, a pulsed test signal and detecting a corresponding return light signal from the device under test representing backscattered and reflected light as a function of distance in the device under test,
- a reference device connectable to said OTDR acquisition device for performing a plurality of OTDR acquisitions toward said reference device, to obtain therefrom a reference measurement as a function of wavelengths across the spectral range of interest;
- and
- a processing unit receiving the plurality of OTDR acquisitions and configured for:
- from the plurality of OTDR acquisitions, extracting values of a reflection level of a reflective peak associated with a reflective surface at a remote end of the optical device under test;
- from the plurality of OTDR acquisitions, extracting values of said reference measurement as a function of wavelengths;
- and
- calculating values of a spectral transmission response associated with said device from the values of reflection level of the reflective peak as a function of said wavelengths, in combination with the reference measurement associated with the reference device.
Dependencies are inferred from the claim text.