Topic
Optical modulator
About: Optical modulator is a research topic. Over the lifetime, 14068 publications have been published within this topic receiving 196932 citations.
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TL;DR: High-speed optical intensity modulation is reported for the first time using single-mode electro-optic interferometric waveguide modulators formed from Ti-diffused waveguides in LiNbO3.
Abstract: High-speed optical intensity modulation is reported for the first time using single-mode electro-optic interferometric waveguide modulators formed from Ti-diffused waveguides in LiNbO3. For cw 0.633-μm optical inputs, modulation at rates up to 1.4 GHz has been achieved by driving the interferometer through multiple-π phase shifts. Envelope modulation of a 275-MHz optical pulse train from a cw mode-locked frequency-doubled Nd:YAG laser with a 68.9-MHz drive signal has also been demonstrated.
61 citations
Patent•
16 Jun 1990
TL;DR: In this paper, the complementary output signals are provided to two separate optical receivers, thereby allowing distribution of optically modulated signals, for example, in a cable television or other type distribution system.
Abstract: A novel optical system is taught including an optical source, an optical modulator (128) having at least one optical input port for receiving the optical signal from the optical source, a modulation port for receiving the optical signal from the optical source, a modulation port for receiving a modulating signal, and complementary output port signals (132). The complementary modulated output signals are applied to one or more optical receivers at the other end of an optical transmission link. In one embodiment, the two complementary signals are provided to two separate optical receivers, thereby allowing distribution of optically modulated signals, for example, in a cable television or other type distribution system. In another embodiment, the two complementary modulated signals are applied to a single balanced receiver, thereby providing information content to the complementary receiver twice the power level available on either one channel alone. Furthermore, utilizing a balanced receiver, common mode error signals cancel, thereby increasing the signal to noise ratio of the system. In one embodiment of this invention, a single optical transmission channel is used, and the two optically modulated signals are separated in polarization (132) so as to be capable of being separately detected on the receiving end of the link. In one embodiment feedback means is used to insure proper polarization states for the two complementary signals.
61 citations
TL;DR: In this article, a novel wavelength insensitive biasing technique is proposed which significantly reduces the second-order distortion and increases the optical bandwidth and sparseness of the optical waveform.
Abstract: Photonic systems that use a variable or chirped optical wavelength and a single Mach-Zehnder modulator have been analyzed to determine the relation between optical bandwidth and spur free dynamic range. A novel wavelength insensitive biasing technique is proposed which significantly reduces the second-order distortion and increases the optical bandwidth.
61 citations
Patent•
14 Apr 1995TL;DR: In this article, an optical head device adapted to be optically coupled to an optical disk includes a light-source laser and an objective lens, which receives an output light of the light source, and causes it to be projected onto the optical disk to form a focused spot thereon.
Abstract: An optical head device adapted to be optically coupled to an optical disk includes a light-source laser and an objective lens optically coupled thereto. This lens receives an output light of the light source, and causes it to be projected onto the optical disk to form a focused spot thereon. Photodetectors which are arranged near the light-source laser are optically coupled to the lens in one optical path so that they are responsive to a light component which is reflected from the optical disk toward the photodetectors by way of the objective lens. A beam-shaping prism is located between the lens and a group of the light source and the photodetectors in the optical path. When the laser output light travels toward the lens, the prism reshapes the light into a predetermined isotropic beam profile. When the reflected light from the optical disk propagates reversely along the same optical path to enter the beam-shaping prism, this prism permits such an incident light to pass through itself toward the photodetectors.
61 citations
TL;DR: In this paper, a method for measuring the chirp parameters and the halfwave voltages of Mach-Zehnder-type optical modulators is described, which can be obtained from the optical spectrum components by using a small signal operation, while the conventional method needs large voltages.
Abstract: A method is described for measuring the chirp parameters and the halfwave voltages of Mach-Zehnder-type optical modulators. These parameters can be obtained from the optical spectrum components by using a small signal operation, while the conventional method needs large voltages. We demonstrated the measurement of the frequency responses up to 40 GHz.
61 citations