An anisotropic spatial acousto-optic modulator for a holographic display system includes a substrate, an anisotropic waveguide that guides light into a single polarization, and a transducer that generates surface acoustic waves that propagate linearly with the guided, polarized light, converting at least some of the polarized light into a leaky mode of orthogonally polarized light. The acoustic waves may be encoded with holographic information. The modulator may include coupling devices for coupling light into the waveguide, which may have multiple channels. A holographic video display system includes at least one anisotropic spatial acousto-optic modulator. The pattern of the surface acoustic waves, encoded with holographic information, acts as a diffraction pattern that causes the modulator output to form a wavefront that becomes at least part of a holographic image. The system may have multiple channels in multiple waveguides, wherein each waveguide writes one or more lines of the holographic image.

Anisotropic Leaky-Mode Modulator for Holographic Video Displays

Flexible hinge and removable attachment techniques are described. In one or more implementations, a flexible hinge is configured to communicatively and physically couple an input device to a computing device and may implement functionality such as a support layer and minimum bend radius. The input device may also include functionality to promote a secure physical connection between the input device and the computing device. One example of this includes use of one or more protrusions that are configured to be removed from respective cavities of the computing device along a particular axis but mechanically bind along other axes. Other techniques include use of a laminate structure to form a connection portion of the input device.

Flexible hinge and removable attachment

The index of refraction of waveguide structures can be varied by altering carrier concentration. The waveguides preferably comprise semiconductors like silicon that are substantially optically transmissive at certain wavelengths. Variation of the carrier density in these semiconductors may be effectuated by inducing an electric field within the semiconductor for example by apply a voltage to electrodes associated with the semiconductor. Variable control of the index of refraction may be used to implement a variety of functionalites including, but not limited to, tunable waveguide gratings and resonant cavities, switchable couplers, modulators, and optical switches.

Tuning the index of a waveguide structure

Crosstalk can be reduced in optical waveguide bundles(110) by varying the widths of individual waveguides(111-161). Using different width waveguides reduces the growth of crosstalk between the optical waveguides, thereby allowing the waveguides to be placed in closer proximity to increase waveguide density on the chip(200) and/or reduce the routing space required for the waveguide bundle(110). Moreover, varying the width of a waveguide spiral may reduce crosstalk, which can increase power efficiency when implemented in coiled or folded waveguide thermal optical (TO) devices.

Compact optical waveguide arrays and optical waveguide spirals

In an OADM system, an OADM device includes an AOTF. The AOTF can select an optional wavelength by changing the frequency of an RF signal to be applied. An optical signal having a specified wavelength can be dropped from a wavelength-multiplexed optical signal input from an input terminal, or a wavelength-multiplexed optical signal input from an add port can be multiplexed with a through optical signal. However, considering the increase in coherent cross talk, the AOTF should be exclusively used for dropping in an actual device configuration. Otherwise, a drop optical signal is branched by an optical coupler with the wavelength selected by a tributary station. Thus, the wavelength selected by the tributary station can be extracted by the AOTF from the through optical signal.

Optical transmission apparatus, optical transmission system, and optical terminal station

A Mach-Zehnder interferometric optical modulator with a monitor has two branched optical waveguides for causing light waves propagated therethrough to interfere with each other. A single light beam applied to an input optical waveguide is divided by a Y-shaped divider into equal light beams which travel through respective optical waveguides. At this time, the light beams in the respective optical waveguides are phase-modulated by ±φ/2 under an external electric field. The phase-modulated light beams are then combined by a Y-shaped coupler into a light beam that travels through output optical waveguides, which output from their output ends the light beams as a main signal and an inverted signal. Of the output light beams, the light beam as the inverted signal is detected as a monitor light beam by a photodetector.

Optical modulator with monitor having 3-dB directional coupler or 2-input, 2-output multimode interferometric optical waveguide

An optical modulator is provided that not only can realize a suitable initial operating point without using dc voltage for control, but that has little optical loss and can obtain an excellent extinction ratio. The optical modulator comprises: a substrate having an electro-optical effect, first and second branch optical waveguides formed in a first major surface of the substrate; an optical branching structure for splitting input optical signal and supplying the split signals to the branch optical waveguides; and a 3-dB directional coupler that couples the outputs of the first and second branch optical waveguides. The ratio of nonuniformity, which is represented by the difference in propagation constants of the two optical waveguides in 3-dB directional coupler, to the coupling coefficient of the 3-dB directional coupler is 1 to at least 5, preferably 1 to at least 15, and still more preferably, 1 to at least 20.

Mach-Zehnder optical modulator

An arrayed waveguide element having flat optical frequency characteristics, and an optical communication system using such arrayed waveguide element are realized by providing the arrayed waveguide element that is prepared by forming an inputting channel waveguide as well as an outputting channel waveguide, a channel waveguide array, a first sector form slab waveguide for connecting the inputting channel waveguide with the channel waveguide array, and a second sector form slab waveguide for connecting the outputting channel waveguide with the channel waveguide array on a substrate. A waveguide part wherein the outputting channel waveguide is connected with the second sector form slab waveguide is defined in a parabolic configuration, whereby flat optical frequency characteristics are realized. Furthermore, it is possible that an individual parabolic configuration is adjusted in response to a wavelength, so that it can cope with a trend of broad band in optical signals.

Arrayed waveguide grating and optical communication system using arrayed waveguide grating

A polarization splitter comprises an optical waveguide formed on a substrate and having an S-shaped curve portion, for permitting propagation of two linearly polarized lights orthogonal to each other therethrough, and an anisotropic optical waveguide branching from the beginning of the S-shaped curve portion, into which is guided one of the two linearly polarized lights alone.

Polarization splitter haivng an anisotropic optical waveguide

An object of the present invention is to provide an optical waveguide device and an optical waveguide module having the function to multiplex/demultiplex or couple/decouple optical signals and particularly to provide an optical waveguide device and an optical waveguide module for realizing low optical loss, reducing wavelength dependence and ensuring easier shape management in the manufacturing and inspection processes. The optical waveguide device and optical waveguide module are provided with a substrate, one or more first waveguides, a plurality of second waveguides, and a slab waveguide for connecting the first waveguides and the second waveguides. At a region where the second waveguides are connected to the slab waveguide, a plurality of waveguide paths are provided for respectively connecting the second waveguides. Width of the waveguide paths is constant. The width of the separation gap between waveguide paths progressively increases as it becomes further away from the slab waveguide or the period of arrangement interval of the waveguide paths progressive increases as it becomes further away from the slab waveguide.

Toru Hosoi

Papers

Optical modulator with monitor having 3-dB directional coupler or 2-input, 2-output multimode interferometric optical waveguide

Mach-Zehnder optical modulator

Arrayed waveguide grating and optical communication system using arrayed waveguide grating

Polarization splitter haivng an anisotropic optical waveguide

Optical waveguide device and optical waveguide module