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Optical modulator

About: Optical modulator is a research topic. Over the lifetime, 14068 publications have been published within this topic receiving 196932 citations.


Papers
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Proceedings ArticleDOI
01 Jul 2004
TL;DR: In this article, a high-speed all-silicon optical phase modulator with a metal-oxide-semiconductor (MOS) capacitance was proposed, which can be used to modulate the phase of the optical mode due to free-carrier plasma dispersion effect.
Abstract: We present design, fabrication, and testing of a high-speed all-silicon optical phase modulator in silicon-on-insulator (SOI). The optical modulator is based on a novel silicon waveguide phase shifter containing a metal-oxide-semiconductor (MOS) capacitor. We show that, under the accumulation condition, the drive voltage induced charge density change in the silicon waveguide having a MOS capacitor can be used to modulate the phase of the optical mode due to the free-carrier plasma dispersion effect. We experimentally determined the phase modulation efficiency of the individual phase shifter and compared measurements with simulations. A good agreement between theory and experiment was obtained for various phase shifter lengths. We also characterized both the low- and high-frequency performance of the integrated Mach-Zehnder interferometer (MZI) modulator. For a MZI device containing two identical phase shifters of 10 mm, we obtained a DC extinction ratio above 16 dB. For a MZI modulator containing a single-phase shifter of 2.5 mm in one of the two arms, the frequency dependence of the optical response was obtained by a small signal measurement. A 3-dB bandwidth exceeding 1 GHz was demonstrated. This modulation frequency is two orders of magnitude higher than has been demonstrated in any silicon modulators based on current injection in SOI.

65 citations

Patent
28 Jul 2008
TL;DR: In this article, an object is irradiated with a laser light modulated by a reflection type spatial light modulator such that aberration of the laser light converged inside the object becomes a predetermined aberration or less.
Abstract: An object is irradiated with a laser light modulated by a reflection type spatial light modulator such that aberration of the laser light converged inside the object becomes a predetermined aberration or less. Therefore, aberration of the laser light generated at a position on which a converging point of the laser light is located is made as small as possible, to enhance the energy density of the laser light at that position, which makes it possible to form a modified region with a high function as a starting point for cutting. In addition, because the reflection type spatial light modulator is used, it is possible to improve the utilization efficiency of the laser light as compared with a transmissive type spatial light modulator.

65 citations

Patent
18 Jan 1994
TL;DR: In this paper, an alignment adjusting system for use in an optical system in an Optical Transceiver, including an optical antenna (10) having a main mirror (1a) and a sub-mirror (2), both of which being provided around an optical axis (CL) of said optical antenna, is presented.
Abstract: In an alignment adjusting system for use in an optical system in an optical transceiver, including an optical antenna (10) having a main mirror (1a) and a submirror (2), both of which being provided around an optical axis (CL) of said optical antenna (10), the optical antenna (10) being coupled through optical coupling means (4, 11 to 15) to the optical transceiver. The optical antenna (10) transmits a beam of transmitting light outputted from the optical transceiver to an optical antenna of a destination station after sequentially reflecting the beam of transmitting light by the submirror (2) and the main mirror (1a). A return-reflection mirror (1b) provided in either one of the main mirror (1a) and the submirror (2) return-reflects a part of the beam of transmitting light. A photodetector (30, 31) detects a defocusing amount of the beam of transmitting light in the optical antenna (10) in response to the beam of transmitting light return-reflected, and a moving mechanism moves the submirror in a direction parallel to the optical axis (CL) of the optical antenna (10). Further, a controller (20) controls the moving mechanism (2d) so that the defocusing amount of the beam of transmitting light becomes substantially zero, in response to a defocusing amount of the beam of transmitting light.

65 citations

Journal ArticleDOI
TL;DR: In this paper, the basic interaction between different optical sources and optical detectors for high-speed optical communication networks has been investigated, and it is observed that the interaction between continuous wave (CW) laser/MZM or CW laser/EAM has presented better performance than other combinations.
Abstract: The study shows the basic interaction between different optical sources and optical detectors for high-speed optical communication networks. Optical sources that are namely continuous wave (CW) laser, laser rate equations as well as the vertical cavity surface emitting laser (VCSEL). The utilized optical modulators are indicated as Mach Zehnder modulator (MZM) as well as the Electro-absorption modulator (EAM). The data rate available 40 Gb/s for propagation length ranges from 10 km to 50 km. It is observed that the interaction between CW laser/MZM or CW laser/EAM has presented better performance than other combinations. In order to measure the system performances, many interesting parameters have been investigated. These can be including the electrical received power, highest signal quality factor, Optical signal per noise ratio as well as the lowest data error rates.

65 citations

Patent
01 Jun 2004
TL;DR: A projection display apparatus for expanding and projecting an image, which is formed by an optical modulator, using a projection lens is described in this paper, where a diaphragm mechanism is disposed between the light source and the optical modulators, and controls an amount of light from the source.
Abstract: A projection display apparatus for expanding and projecting an image, which is formed by an optical modulator, using a projection lens A light source illuminates the optical modulator A first lens array divides light emitted from the light source into a plurality of partial luminous fluxes A second lens array superimposes the plurality of partial luminous fluxes emitted from the first lens array onto the optical modulator A diaphragm mechanism is disposed between the light source and the optical modulator, and controls an amount of light from the light source A traveling direction of the light emitted from the light source is defined as a Z-axis, a direction perpendicular to the Z-axis is defined as an X-axis, and a direction perpendicular to a plane formed by the Z-axis and the X-axis is defined as a Y-axis An area of an opening of the diaphragm mechanism changes in a direction of the X-axis or the Y-axis

65 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202342
2022154
2021166
2020289
2019311
2018325