Abstract: The present invention provides a method and apparatus for random number generation using a scattering waveguide. The apparatus includes a light source for providing coherent light and a scattering waveguide for receiving the coherent light and providing scattered light. The relative position of the light source and the scattering waveguide are variable. The apparatus also includes a detector for forming at least one random number based on the scattered light.

Abstract: The present invention provides a method and apparatus for random number generation using a scattering waveguide. The apparatus includes a light source for providing coherent light and a scattering waveguide for receiving the coherent light and providing scattered light. The relative position of the light source and the scattering waveguide are variable. The apparatus also includes a detector for forming at least one random number based on the scattered light.

Abstract: An optical amplifier is provided from a body 21, at least part 25 of which is doped with a rare earth such as erbium. At least one waveguide 47 extends through the doped part of the body. Pump light 51 is input on a side face 35 of the body and is distributed in the body over the length of the waveguide 47. A reflective coating 57 may be provided away from the pump light input, including on the opposite face 37 to the pump light input, to multiply reflect pump light within the body 21 to distribute the pump light within the body. The body may be in the form of a slab.

Abstract: Dispersion compensation devices are described which comprise waveguides including sampled Bragg gratings which exhibit comb-like reflectance characteristics. The profile of effective refractive index along the length of the grating is controlled to adjust the position of the teeth and/or to control the dispersion exhibited by the device (i.e. to control the chirp of the grating). The devices can thus be used to provide dispersion compensation to any one of a number of wavelength channels in a WDM system. In preferred arrangements, the effective refractive index distribution is set by a applying a temperature distribution along the length of the grating, or by setting an applied electric field.

Abstract: An optical waveguide device is described comprising an optical input, an optical output and a strip-loaded waveguide connected between the input and the output. The device further includes an additional material positioned adjacent a portion of the waveguide, the material having a higher refractive index than the waveguide such that an optical signal guided by the waveguide will at least partially couple into the material.

Abstract: Dispersion compensation devices are described which comprise waveguides including sampled Bragg gratings which exhibit comb-like reflectance characteristics. The profile of effective refractive index along the length of the grating is controlled to adjust the position of the teeth and/or to control the dispersion exhibited by the device (i.e. to control the chirp of the grating). The devices can thus be used to provide dispersion compensation to any one of a number of wavelength channels in a WDM system.

Abstract: An optical amplifier is provided from a body 21, at least part 25 of which is doped with a rare earth such as erbium. At least one waveguide 47 extends through the doped part of the body. Pump light 51 is input on a side face 35 of the body and is distributed in the body over the length of the waveguide 47. A reflective coating 57 may be provided away from the pump light input, including on the opposite face 37 to the pump light input, to multiply reflect pump light within the body 21 to distribute the pump light within the body. The body may be in the form of a slab.

Abstract: An optical waveguide format tuneable optical filter is formed using Bragg grating reflectors to define one or more optical cavities of a Fabry Pérot etalon, the or each cavity of the etalon including one or more slots containing a controllable refractive index medium, for instance a silicone gel whose index is regulated by Joule heating, or a polymer dispersed liquid crystal whose index is electric field regulated. Strong coupling coefficient (˜ a few tens mm−1) gratings may be made using lithography to form linear arrays of buried high index inclusions extending along the waveguide core axis.