Method and apparatus for operating variable optical attenuator by modulating the attenuation thereof
AssigneeTropic Networks Inc.
InventorsGordon Bruce Scarth, Robert Michael Bierman, Steve Joseph Grabner
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Abstract
A method and apparatus are disclosed for operating an eVOA by modulating its attenuation. If an optical signal power is below a loss of signal (LOS) power threshold the eVOA attenuation is set to a maximum attenuation and then, periodically and quickly decreased and increased in steps while checking for the presence of optical signals above the LOS power threshold. The method is also used for operating a multiplicity of eVOAs while minimizing the risk of damage to optical network equipment.
Claims14
A method for operating an electronically controlled variable optical attenuator (eVOA) inserted in an optical path of an optical signal, the method comprising the steps of:
- monitoring an optical signal power at an output of the eVOA;
- setting the attenuation of the eVOA to a substantially maximum attenuation (MaxAtt);
- and
- modulating the attenuation of the eVOA, by decreasing and increasing the eVOA attenuation in steps until the optical signal power is detected above the LOS power threshold, or the maximum attenuation (MaxAtt) is reached.
An apparatus for operating an electronically controlled variable optical attenuator (eVOA) inserted in an optical path of an optical signal, comprising:
- a microcontroller for monitoring an optical signal power at an output of the eVOA;
- setting the attenuation of the eVOA to a substantially maximum attenuation (MaxAtt);
- and
- modulating the attenuation of the eVOA by decreasing and increasing of the eVOA attenuation in steps until the optical signal power is detected above the LOS threshold, or the maximum attenuation (MaxAtt) is reached.
Dependencies are inferred from the claim text.