Jds Uniphase Corporation

Electrophotonics Corporation

A Tino Alavie

Robert Maaskant

Frank Faqiu Liang

Nigel Copner

Keith Beckley

Shangyuan Huang

Myo Myint Ohn

Ming Gang Xu

Michael J LeBlanc

Raymond M Measures

An optical performance monitor having a tunable fiber grating sandwiched between the first and second reflective surfaces of a fiber etalon provides high sensitivity, while simultaneously monitoring an optical data signal. Individual channels within the optical data signal are monitored by tuning the fiber grating over the wavelength range of the optical data signal to measure an intensity of each channel. As the tunable grating scans the wavelength range of interest, it simultaneously changes the resonant cavity length of the etalon, thus allowing the etalon to effectively monitor the tunable grating with a wavelength outside the wavelength range of the optical data signal.

Optical performance monitor

The method and apparatus forming the present invention allows for rapid analysis of the optical spectrum and its content by controlling the spectral position of a channel select element and using a ratiometric wavelength and power determination technique to accurately analyze the transmitted or elected portion of the optical spectrum. The channel select element can be either a transmissive or reflective device which can be tuned by way of a control signal. The system can be operated in either scan and post process mode or in a continuous feedback mode where the position of the channel select element is determined by the ratiometric wavelength determination system and used to control the wavelength position of the channel select element. The ratiometric wavelength and power determination system, in its typical form, is based on dividing the spectrally encoded optical signal into two parts. One part of this signal passes through an optical filter with continuously increasing or decreasing transmission as a function of wavelength while the other part is unperturbed. The two parts and subsequently detected by optical to electrical detectors where the electrical signal is proportional to the optical signal. Dividing the two signals reveals a unique number which is a power independent representation of the input wavelength. The present invention advantageously provides a method and device to measure simultaneously several carriers and not just one. Furthermore, in the present invention, a power measurement is obtained by using the unfiltered part of the optical signal.

Method and apparatus for optical performance monitoring in wavelength division multiplexed fiber optical systems

The present invention provides a method and apparatus for controlling the detailed strain field imposed on a guided-wave Bragg grating. The spectral and temporal form of radiant energy traveling down optical fibers is important in many fields, including communications and sensing. The spectral distribution and center wavelength of short optical pulses is of particular importance. In the communication field the information carrying capacity of an optical fiber can be limited by the dispersion experienced by short pulses as they propagate along an optical fiber. Chirped fiber optic intracore Bragg gratings can be used to compensate for this dispersion. However, a grating with a different degree of chirp would be required for each particular communication system. This control of the intra-grating strain distribution allows the grating to be tuned over a broad spectral range or chirped in a manner that permits it to compensate for a wide range of dispersion with or without a shift in the grating center wavelength. In addition, precise control of the strain distribution along a grating can be used to manufacture a variety of spectral filters.

Apparatus and method of bragg intra-grating strain control

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Richmond Hill, Canada

A Tino Alavie