Abstract: There is disclosed an optical device for dispersion compensation of channels within a predetermined wavelength band, comprising: a waveguiding structure; and a grating structure formed in said waveguiding structure; characterized in that said grating structure has a Bragg frequency profile that is divided into contiguous periods, wherein the Bragg frequencies within each period vary between a lower Bragg frequency and an upper Bragg frequency, said lower and upper Bragg frequencies for each period both corresponding to wavelengths outside of said predetermined wavelength band.

Abstract: There is disclosed an optical device for dispersion compensation of channels within a predetermined wavelength band, comprising: a waveguiding structure; and a grating structure formed in said waveguiding structure; characterized in that said grating structure has a Bragg frequency profile that is divided into contiguous periods, wherein the Bragg frequencies within each period vary between a lower Bragg frequency and an upper Bragg frequency, said lower and upper Bragg frequencies for each period both corresponding to wavelengths outside of said predetermined wavelength band.

Abstract: A spectrally selective optical coupler is disclosed, comprising a first and a second waveguide; an external resonator defined by at least a first and a second mirror; and a respective deflecting portion in each of said waveguides for coupling light between the waveguide and the external resonator. The waveguides are arranged between the mirrors adjacent to each other in a plane that is generally parallel to said mirrors; and the external resonator is designed such that a resonant mode within the external resonator overlaps the deflecting portion in the first and the second waveguide. The inventive coupler solves some limiting geometrical problems encountered in the prior art. A lateral extension of a mode in the external resonator overlapping both waveguides is obtained using a curved resonator mirror or refractive elements or portions within the resonator.

Abstract: The invention is a spectrally selective optical coupler with a new geometry and a new principle of action. An optical coupler according to the invention comprises an optical fiber and an external lightguide. In the fiber there is provided a deflector that is operative to deflect light of a predetermined wavelength into a propagating mode of said lightguide. The outcoupled light is transferred to a region remote from the outcoupling portion of the fiber. The invention can be used to couple light from a first to a second optical fiber.

Abstract: A spectrally selective optical coupler is disclosed, comprising a first and a second waveguide; an external resonator defined by at least a first and a second mirror; and a respective deflecting portion in each of said waveguides for coupling light between the waveguide and the external resonator. The waveguides are arranged between the mirrors adjacent to each other in a plane that is generally parallel to said mirrors; and the external resonator is designed such that a resonant mode within the external resonator overlaps the deflecting portion in the first and the second waveguide. The inventive coupler solves some limiting geometrical problems encountered in the prior art. A lateral extension of a mode in the external resonator overlapping both waveguides is obtained using a curved resonator mirror or refractive elements or portions within the resonator.

Abstract: The invention relates to the coupling of light to and from an optical waveguide, such as an optical fiber. Light of a specific wavelength is deflected out from the fiber, or into the fiber, in a substantially transverse direction with respect to the propagation direction of light in the waveguide, by a deflector 16 arranged in the fiber core 10. Wavelength selectivity of the deflector 16 is provided by a Bragg grating means located in the fiber core 10. The deflected light is collimated, or converged towards a focus, by an interface 15 between a cladding 11, having one index of refraction, and an outer medium 12, having another index of refraction. The ratio between the radius of the cladding 11 and the radius of the core 10 made sufficiently small for the collimating, or converging, effect to appear.

Abstract: The invention is a spectrally selective optical coupler with a new geometry and a new principle of action. An optical coupler according to the invention comprises an optical fiber and an external lightguide. In the fiber there is provided a deflector that is operative to deflect light of a predetermined wavelength into a propagating mode of said lightguide. The outcoupled light is transferred to a region remote from the outcoupling portion of the fiber. The invention can be used to couple light from a first to a second optical fiber.

Abstract: There is disclosed a harmonic modulation device of waveguide type including a semiconductor laser, a waveguide for generating a nonlinear optical harmonic of the semiconductor laser by keeping phase matching, means for leading an optical beam of the semiconductor laser to the waveguide, electrodes disposed on the waveguide, and means for modulating a refractive index of the waveguide electro-optically to modulate a phase matching condition and thereby modulate an intensity of the harmonic.

Abstract: A short-wavelength laser having a stable output and an optical information processing system capable of high-density recording are disclosed. A solid-state laser is used as a light source, and a nonlinear optical crystal is arranged in a resonator in order to produce a short wavelength by means of a solid-state laser. The retardation of the nonlinear optical crystal is controlled by determining the length of the nonlinear optical crystal. A solid-state laser device having a stable output with the noise removed from a pumping power light source is also provided. Further, the solid-state laser device is used as a light source for the optical information processing system, and the light of irrelevant wavelengths contained in the light from the solid-state laser device are removed by a device having the ability to select wavelengths. Thus, not only a stable light source with a short wavelength but also an optical information processing system capable of high-density recording are realized.