Abstract: A wavelength tunable filter for optical communication systems has an optical fiber containing a Bragg grating disposed within a compliant support block. A length of the fiber is wrapped in a spiral of fixed pitch around the longitudinal axis of a cylindrical polymer support block. The support block is placed within a support frame to which a micrometer screw assembly is attached and oriented to apply a variable mechanical load substantially parallel to the longitudinal axis of the cylindrical support block. Application of the load introduces a strain on the support block, changing the period of the refractive index in the fiber Bragg grating with a resulting shift in the Bragg reflection peak.

Abstract: A wavelength tunable filter for optical communication systems has an optical fiber containing a Bragg grating disposed within a compliant support block. A length of the fiber is wrapped in a spiral of fixed pitch around the longitudinal axis of a cylindrical polymer support block. The support block is placed within a support frame to which a micrometer screw assembly is attached and oriented to apply a variable mechanical load substantially parallel to the longitudinal axis of the cylindrical support block. Application of the load introduces a strain on the support block, changing the period of the refractive index in the fiber Bragg grating with a resulting shift in the Bragg reflection peak.

Abstract: The invention includes a method and apparatus for monitoring wavelength of an optical channel. A tunable optical bandpass filter is used to correlate a signal from an optical transmission line with a signal from a reference light source. The signal from the reference light source passes through a reference gas cell. The absorption lines of the reference gas provide a known calibration standard against which measured values may be compared. The invention finds applications in optical transmission systems, including wavelength division multiplexed and dense wavelength division multiplexed (WDM and DWDM) optical communication systems.

Abstract: A wavelength tunable filter for optical communication systems has an optical fiber containing a Bragg grating disposed within a compliant support block. A length of the fiber is wrapped in a spiral of fixed pitch around the longitudinal axis of a cylindrical polymer support block. The support block is placed within a support frame to which a micrometer screw assembly is attached and oriented to apply a variable mechanical load substantially parallel to the longitudinal axis of the cylindrical support block. Application of the load introduces a strain on the support block, changing the period of the refractive index in the fiber Bragg grating with a resulting shift in the Bragg reflection peak.

Abstract: A tunable dispersion compensating device for optical communications systems has a compliant support block having a longitudinal axis and a load-receiving surface oriented substantially parallel to the longitudinal axis. The load receiving surface is suitable to receive an applied load in a direction substantially orthogonal to the longitudinal axis. A Bragg-grating fiber is disposed in the compliant support block and extends substantially along, and at an angle to, the longitudinal axis of the compliant support block.

Abstract: A method enhances photosensitivity of an optical element by disposing the optical element in a confinement chamber, introducing a hydrogen-rich atmosphere into the confinement chamber and regulating temperature of the hydrogen-rich atmosphere over a treatment time. The temperature regulation includes increasing the temperature of the hydrogen-rich atmosphere over a portion of the treatment time. A method for producing an optical element includes exposing the optical element to a hydrogen-rich atmosphere for a treatment period of time varying temperature of the hydrogen-rich atmosphere during the treatment period and irradiating the optical element with electromagnetic radiation.

Abstract: An add-drop multiplexer is described, in one embodiment the add-drop multiplexer includes an optical transmission signal input port adapted to receive a wavelength division multiplexed optical transmission signal, an optical transmission signal output port adapted to output at least a portion of the wavelength division multiplexed optical transmission signal, an add-drop optical channel port adapted to receive an optical add channel and output an optical drop channel, and a wavelength selective optical filter arranged between the optical transmission signal input port, the optical transmission signal output port and the optical add-drop channel port. The wavelength selective optical filter reflects optical channels that will continue through the add-drop multiplexer along a transmission line to the optical transmission signal output port and permits an optical channel that is to be dropped to pass therethrough.