Optical performance monitors
AssigneeAlliance Fiber Optic Products, Inc.
InventorsTongxin Lu, Zheng Yan
Life of this patent
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Abstract
Method and apparatus for wavelength control and measurement are disclosed. An optical signal to be measured is tapped off a portion thereof referring to as a source signal. Together with a reference signal, the source signal is coupled to a tunable filter. The frequency response or passing band of the tunable filter is so controlled that one wavelength λx from the source signal and one wavelength λrx from the reference signal transmit through. Relying on a band separation filter, the wavelength λrx is separated from the reference signal and coupled to a gas cell of a known spectrum, a filtered signal of the wavelength λrx is then coupled to a photo-detector for subsequent electrical measurement. In accordance with the known spectrum, the wavelength λx can be precisely derived.
Claims15
An optical measurement system comprising:
- a coupler receiving a source signal and a reference signal and producing a combined signal;
- a tunable filter receiving the combined signal, the tunable filter being so controlled that the tunable filter outputs one wavelength λx from the source signal and one wavelength λrx from the reference signal;
- a band separation filter coupled to the tunable filter to separate the wavelength λrx from the wavelength λx;
- and
- a gas cell of a known frequency response receiving the wavelength λrx and producing a filtered signal to be electrically measured so that the wavelength λx can be derived.
A method for an optical measurement system, the method comprising:
- receiving a source signal and a reference signal;
- combining the source signal and the reference signal to produce a combined signal;
- filtering the combined signal by a tunable filter, wherein the tunable filter is so controlled that the tunable filter outputs one wavelength λx from the source signal and one wavelength λrx from the reference signal;
- separating the wavelength λrx from the wavelength λx;
- coupling the wavelength λx to a gas cell of a known frequency response;
- and
- producing a filtered signal to be electrically measured so that the wavelength λx is to be calculated.
Dependencies are inferred from the claim text.