Abstract: In a method and system for providing dispersion compensation in an optical system, there is coupled into the optical system at least one pathway into which there is connected a tunable chirped fiber Bragg grating, each such grating providing a respective tunable amount of dispersion. At least one respective DGD element is connected into the respective pathway for each such grating. The set of all such respective DGD elements in a given pathway introduces a bias differential group delay DGD(bias) having an absolute value that, for at least one tuning value of the grating, is substantially equal to differential group delay introduced by the grating.

Abstract: In a method and system for providing dispersion compensation in an optical system, there is coupled into the optical system at least one pathway into which there is connected a tunable chirped fiber Bragg grating, each such grating providing a respective tunable amount of dispersion. At least one respective DGD element is connected into the respective pathway for each such grating. The set of all such respective DGD elements in a given pathway introduces a bias differential group delay DGD(bias) having an absolute value that, for at least one tuning value of the grating, is substantially equal to differential group delay introduced by the grating.

Abstract: A twin core fiber for sensor applications is developed. It is particularly useful in de-coupling the strain and temperature and thus obtaining both measurement parameters at the same time and location. It is also particularly useful for measuring the temperature in a high humidity environment. The twin core fiber has two cores and each of the cores having a different dopant regime. Also, each of the cores includes a grating having substantially the same grating period.

Abstract: A technique is described for reducing group delay ripple in a fiber dispersion compensation grating. The grating is mounted into a trimming setup that includes a trimming device and a scanning assembly for causing a region of the grating to be scanned along its length by the trimming device output. The grating is sensitive to the trimming device output, such that exposure to the trimming device output causes a change in the effective refractive index of the scanned region, the amount of change varying as a function of scanning velocity. A region of the grating to be trimmed is selected, and a scanning velocity profile is programmed into the scanning assembly that is calculated to modify the effective refractive index of the selected grating region along its length so as to smooth out group delay ripple in the selected grating region.

Abstract: In a method and system for providing dispersion compensation in an optical system, there is coupled into the optical system at least one pathway into which there is connected a tunable chirped fiber Bragg grating, each such grating providing a respective tunable amount of dispersion. At least one respective DGD element is connected into the respective pathway for each such grating. The set of all such respective DGD elements in a given pathway introduces a bias differential group delay DGD(bias) having an absolute value that, for at least one tuning value of the grating, is substantially equal to differential group delay introduced by the grating.

Abstract: A fiber optic sensor employs tapered fiber optics in a tapered gun barrel. The fiber optic sensor employs a single-mode optical fiber, a light source supplying light to the single-mode fiber and at least one tapered dual-mode optical fiber secured to the barrel in a longitudinal direction. The single-mode fiber is spliced to with an end of a proximal one of the dual-mode fibers for carrying the light signal. A partial reflector is inserted between the dual-mode fibers to partially reflect and partially transmit light. A reflector is coupled to a distal end the dual-mode fiber, at the open end of the muzzle of the gun, to reflect the transmitted light. A coupler couples the single-mode fiber to the proximal dual-mode fiber. A coherent multiplexer is connected to the coupler for receiving and multiplexing the reflected light. A processor is responsive to the multiplexer for processing the multiplexed sensing information.

Abstract: The invention herein provides a method and apparatus for fabricating optical fiber vibration modal filtering sensors. Such filtering sensors are used in vibration control of engineered structures, especially flexible structures. In particular, the optical fiber sensor is made by a functionally weighted exposure of an optical fiber to ultra-violet (UV) laser source thereby modifying the refractive index of the optical fiber core resulting in a vibrational modal filtering sensor using a single mode interferometric detection scheme. The apparatus for making the same uses a multiple reel stepper motor mechanism, a process controller and a UV laser source.