A device for modulating an amplitude of a light beam, comprising a coherent light source configured to generate a phase-modulated beam having a plurality of frequency components; and a dispersive optical element. The dispersive optical element has a group delay dispersion and is configured to receive the phase-modulated beam, to introduce an optical phase shift to each of the plurality of the frequency components, so that the values of the optical phase shift vary non-linearly with frequency according to the group delay dispersion, and to recombine the plurality of frequency components, thereby generating an amplitude-modulated beam.

Embodiments of present invention provide a digital dispersion compensation module. The digital dispersion compensation module includes a multi-port optical circulator and a plurality of dispersion compensation units connected to the multi-port optical circulator, wherein at least one of the plurality of dispersion compensation units includes a first and a second reflectively terminated element and an optical switch being capable of selectively connecting to one of the first and second reflectively terminated elements, and wherein the at least one of the plurality of dispersion compensation units is adapted to provide a substantially zero dispersion to an optical signal, coming from the multi-port optical circulator, when the optical switch connects to the first reflectively terminated element and is adapted to provide a non-zero dispersion to the optical signal when the optical switch connects to the second reflectively terminated element.

A method of dispersion compensation in an optical device is disclosed. The method may include identifying a first hologram grating vector of a grating medium of the optical device. The first hologram grating vector may correspond to a first wavelength of light. The method may include determining a probe hologram grating vector corresponding to a second wavelength of light different from the first wavelength of light. The method may also include determining a dispersion-compensated second hologram grating vector based at least in part on the probe hologram grating vector and the first hologram grating vector. A device for reflecting light is disclosed. The device may include a grating medium and a grating structure within the grating medium. The grating medium may include a dispersion compensated hologram.

According to embodiments of the present disclosure, an optical device for dispersion compensation is provided. The optical device may include a channel waveguide and two sidewalls coupled to at least a portion of the channel waveguide. The two sidewalls may be respectively arranged at opposing sides of the channel waveguide along a longitudinal axis of the channel waveguide. Each of the two sidewalls may include a plurality of optical elements arranged along the channel waveguide of the waveguide, and the plurality of optical elements may be configured to interact with light propagating in the waveguide so as to compensate dispersion of the light by transmitting the light in a regime close to a stopband of the plurality of optical elements defined by a period of the plurality of optical elements.

In order to reduce a high frequency loss of a substrate-type optical waveguide without facilitating, in a low frequency domain, a reflection by an entrance end of a traveling-wave electrode, the substrate-type optical waveguide includes a coplanar line, provided on an upper surface of an upper cladding, which includes (i) a traveling-wave electrode connected to a P-type semiconductor region and (ii) an earth conductor connected to an N-type semiconductor region. The traveling-wave electrode and the earth conductor are provided so that a distance D therebetween decreases as a distance from an entrance end of the traveling-wave electrode increases.

An optical waveguide interferometer that includes a first optical section, a second optical section, and a set of optical waveguides configured to connect the first and second optical sections, such that light propagating between the first optical section and the second optical section passes through each optical waveguide in the set, wherein the set of optical waveguides includes a first optical waveguide having a first length and a first width and a second optical waveguide having a second length and a second width, wherein the second length is greater than the first length, and the second width is greater than the first width.

An optical device is equipped with an input/output module having at least one optical fiber, a movable mirror which deflects, toward the input/output module, light that is received from the input/output module, and a lens which couples the input/output module and the deflection unit to each other optically and has a focal length that is greater than or equal to 2.0 mm and shorter than 3.5 mm. A dispersion index of the optical device that is given by an equation:
={n(1.45)1}/{n(1.2)n(1.7)}
where n(1.45), n(1.2), and n(1.7) are refractive indices of a glass material of the lens at wavelengths 1.45 m, 1.2 m, and 1.7 m, respectively, is larger than or equal to 100. The wavelength dependence of an optical characteristic of this optical device is weaker than that of conventional optical devices.

Providing an image extraction section with a plurality of video light reflection surfaces that are Fresnel-shaped reflection surfaces allows reduction in the thickness of a light guide apparatus and hence the thickness and size of a virtual image display apparatus. In particular, providing a dispersion elimination section for eliminating wavelength dispersion in correspondence with the image extraction section suppresses image deterioration resulting from dispersion (chromatic aberrations) on a wavelength band basis.

An apparatus, system, and method to counteract group velocity dispersion in fibers, or any other propagation of electromagnetic signals at any wavelength (microwave, terahertz, optical, etc.) in any other medium. A dispersion compensation step or device based on dispersion-engineered metamaterials is included and avoids the need of a long section of specialty fiber or the need for Bragg gratings (which have insertion loss).

Providing an image extraction section with a plurality of video light reflection surfaces that are Fresnel-shaped reflection surfaces allows reduction in the thickness of a light guide apparatus and hence the thickness and size of a virtual image display apparatus. In particular, providing a dispersion elimination section for eliminating wavelength dispersion in correspondence with the image extraction section suppresses image deterioration resulting from dispersion (chromatic aberrations) on a wavelength band basis.