Topic
Optical modulator
About: Optical modulator is a research topic. Over the lifetime, 14068 publications have been published within this topic receiving 196932 citations.
Papers published on a yearly basis
Papers
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16 Dec 1991TL;DR: In this paper, a cellular mobile-radio system with radio stations and transmission facilities remote therefrom, the radio stations send out radio signals and receive radio signals which, in each case, contain information signals.
Abstract: In a cellular mobile-radio system with radio stations and transmission facilities remote therefrom, the radio stations send out radio signals and receive radio signals which, in each case, contain information signals. According to the invention, as many as possible of the processing functions are shifted from the radio stations to the transmission facilities. The radio signal to be sent out by the radio station is easily generated in the radio station because in the transmission facility, an unmodulated carrier and a carrier modulated with the information signal is produced, in which case the carriers differ in frequency by the amount of the carrier frequency of the radio signal. These two optical carriers are transmitted to the radio station and are mixed there in an optical receiver, so that the radio signal containing the information signal is generated. A radio signal that is received in a radio station is transmitted optically to a the transmission facility and is processed further there. This transmission is carried out by the fact that an optical transmitter present in the transmission facility generates an unmodulated optical carrier and transmits it to an optical modulator located in the radio station. In the optical modulator, the light, modulated with the received radio signals, is sent back and the radio signal is recovered by optical heterodyne reception of the unmodulated and modulated carrier.
50 citations
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TL;DR: In this article, the authors presented an optimized design and detailed simulation of an all-silicon optical modulator based on a silicon waveguide phase shifter containing a metaloxide-semiconductor (MOS) capacitor.
Abstract: We present an optimized design and detailed simulation of an all-silicon optical modulator based on a silicon waveguide phase shifter containing a metal-oxide-semiconductor (MOS) capacitor. Based on a fully vectorial Maxwell mode solver, we analyze the modal characteristics of the silicon waveguide. We show that shrinking the waveguide size and reducing gate oxide thickness significantly enhances the phase modulation efficiency because of the optical field enhancement in the voltage induced charge layers of the MOS capacitor, which, in turn, induce refractive index modulation in silicon due to free carrier dispersion effects. We also analyze the device speed by transient semiconductor device modeling. As both optical absorption and modulation bandwidth increase with increasing doping concentration, we show that, with a nonuniform doping profile in the waveguide, balance between the device operation speed and optical loss can be realized. Our simulation suggests that a TE-polarized optical phase modulator with a bandwidth of 10 GHz and an on-chip optical loss less than 2 dB is achievable in silicon.
50 citations
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08 Jul 1985TL;DR: In this paper, the waveguide end facing the laser is vibrated by mechanical means to modulate the coupled light and the position information contained in the oscillatory component of the signal is decoded and applied to a positioning device which then reduces misalignment between the wave guide and the laser.
Abstract: To position a light output device such as a laser diode relative to a light device such as a waveguide so as to obtain maximum coupling of light, the waveguide end facing the laser is vibrated by mechanical means to modulate the coupled light. Light is detected from a remote end of the fiber and a corresponding electrical signal is generated. Positional information contained in the oscillatory component of the signal is decoded and applied to a positioning device which then reduces misalignment between the waveguide and laser. The positioning device continuously seeks the maximum coupling position. The technique finds particular application in positioning a waveguide in a laser package prior to and during anchoring.
50 citations
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01 Jun 2006TL;DR: In this paper, a laser image display consisting of a laser light source emitting laser light, a beam deflector element for receiving laser light and deflecting its advancing direction, an optical integrator for receiving and guiding the deflected laser light to output from its outputting end face, a false surface light source element for scattering the deflection laser light.
Abstract: A laser image display comprising a laser light source emitting laser light, a beam deflector element for receiving laser light and deflecting its advancing direction, a beam deflecting element control section for controlling the degree of deflection performed by the beam deflector element, an optical integrator for receiving and guiding the deflected laser light to output from its outputting end face, a false surface light source element for scattering the deflected laser light, and a modulation element for receiving and modulating the laser light scattered by the false surface light source element.
50 citations
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TL;DR: In this article, the operation of InAsyP1−y/InP multiple quantum well optical modulators at wavelengths compatible with solid-state lasers such as neodymium-doped yttrium aluminum garnet was reported.
Abstract: We report the operation of strained‐layer InAsyP1−y/InP multiple quantum well optical modulators at wavelengths compatible with solid‐state lasers such as neodymium‐doped yttrium aluminum garnet. A structure having 50 periods of 100 A InAsyP1−y quantum wells with 100 A InP barriers is described that has an exciton peak at 1.05 μm and a single pass transmission contrast ratio of 1.4. Favorable comparison is made to similar InxGa1−xAs/GaAs structures.
50 citations