Showing papers on "Extinction ratio published in 1978"
TL;DR: In this paper, an experimental integrated optical version of the Mach-Zehnder interferometer switch, analogous to the microwave balanced bridge, is reported, formed by 3μm-wide Ti-diffused strip waveguides in LiNbO3 and the switch utilizes electro-optical tuning to achieve 3dB operation of the directional couplers.
Abstract: An experimental integrated optical version of the Mach‐Zehnder interferometer switch, analogous to the microwave balanced bridge, is reported. The bridge is formed by 3‐μm‐wide Ti‐diffused strip waveguides in LiNbO3 and the switch utilizes electro‐optical tuning to achieve 3‐dB operation of the directional couplers. The switching voltage required to switch between the states, corresponding to a π phase shift in one arm, equals 14.8 V. The cross talk between channels that corresponds to the extinction ratio when operated as an on‐off modulator is −21.6 dB.
90 citations
TL;DR: An electro-optical, directional coupler switch is demonstrated that requires only a 3-V drive and operates at data rates in excess of 100 Mbit/sec and has an extinction ratio of 13 dB and a 1-mW/M bit/sec figure of merit.
Abstract: An electro-optical, directional coupler switch is demonstrated that requires only a 3-V drive. Used as an amplitude modulator, the device operates at data rates in excess of 100 Mbit/sec (return-to-zero format) and has an extinction ratio of 13 dB and a 1-mW/Mbit/sec figure of merit.
53 citations
TL;DR: In this article, a low drive-voltage optical modulator using a Ti-diffused UNbO3 optical waveguide has been fabricated, and the halfwave voltage, 3 dB bandwidth, optical insertion loss and extinction ratio were 3·8 V, 850 MHz, 10 dB and 13 dB, respectively.
Abstract: A low drive-voltage optical modulator using a Ti-diffused UNbO3 optical waveguide has been fabricated. Stabilization against ambient temperature change was realized by using a miniature halfwave plate. The halfwave voltage, 3 dB bandwidth, optical insertion loss and extinction ratio were 3·8 V (at 1·06μm wavelength), 850 MHz, 10 dB and 13 dB, respectively. A reduction scheme for the optical absorption caused by metallic electrodes, and an analysis of the modulator high frequency response are also reported.
19 citations
TL;DR: In this article, an integration of an intensity light modulator and a LOC-DBR laser on a single chip was demonstrated, and an extinction ratio of more than 10 was obtained.
Abstract: Integration of an intensity light modulator and a LOC‐DBR laser on a single chip has been demonstrated. The injection‐type modulator gives a variable loss (or gain) to the laser light, coupled to it via an interconnecting waveguide, and thus modulates its intensity in accordance with the injected current of the modulator. An extinction ratio of more than 10 was obtained.
18 citations
TL;DR: In this article, a new type of GaAs electro-optic directional-coupler switch for monolithic integrated optics has been proposed and demonstrated using a pair of closely spaced low-loss (α ≈ 22 dB/cm at 115 μm) single-mode rib waveguides with Au Schottky barriers.
Abstract: A new type of GaAs electro-optic directional-coupler switch for monolithic integrated optics has been proposed and demonstrated The devices were fabricated from a pair of closely spaced low-loss (α ≈ 22 dB/cm at 115 μm) single-mode rib waveguides with Au Schottky barriers A 30 dB extinction ratio in the input channel was measured at a reverse-bias voltage of 24 V and the switches have a potential bandwidth of 2 GHz
18 citations
TL;DR: In this paper, the authors describe the successful operation of a buried heterojunction electroabsorption modulator, fabricated from AlyGa1−yAs 1−xSbx/GaAs1−x′SbX′, which is particularly well suited for use with narrow spectral width sources such as the Nd :
Abstract: We describe the successful operation of a buried heterojunction electroabsorption modulator. This modulator, fabricated from AlyGa1−yAs1−xSbx/GaAs1−x′Sbx′, is particularly well suited for use with narrow spectral width sources such as the Nd : YAG fiber lasers. The GaAs1−x′Sbx′ crystal composition can be adjusted to permit operation in the wavelength range 0.9–1.2 μm. At 1.06 μm we have obtained an extinction ratio of 13 dB and a projected insertion loss of 4.0 dB. The low device capacitance permits operation at greater than 900 MHz.
16 citations
7 citations
TL;DR: In this paper, a new type of light modulator, in which incident light polarization is converted to perpendicular polarization by electro-optic effect of r51, was studied, using an a-cut LiTaO3 with a Li/Ta1.2 composition.
Abstract: A new type of light modulator, in which incident light polarization is converted to perpendicular polarization by electro-optic effect of r51, was studied, using an a-cut LiTaO3 with a Li/Ta1.2 composition. A spatially periodic electric field for phase-matching between two crossed polarizations is generated by a pair of interdigital electrodes. The electrode period is changed along the light path so that phase-match condition can be satisfied over a wide temperature range. Birefringence inhomogeneity along the light path was found to contribute to wider operation temperature ranges. An extinction ratio of above 30 dB and 73% conversion with an applied voltage of 180 V were obtained in the modulator. Measured temperature characteristics were almost coincident with calculated values.
5 citations
TL;DR: In this article, an electrically tunable transverse tapered structure for optical guided wave modulation was presented. But the extinction ratio was 75% for a switching voltage of 20 volt.
2 citations
TL;DR: In this article, error performance in optical communication with differential pulse-position modulated optical carrier is discussed. And both threshold type and maximum value type of decision schemes are also considered, including the effects of several parameters, such as the number of time slots, the duty ratio, the extinction ratio, count dimension, the signal-to-background radiation power ratio, and the signal tothermal noise power ratio.
Abstract: Error performance in optical communication, where the information is transmitted by means of the differential pulse-position modulated optical carrier, is discussed. Additive independent background radiation and thermal noise are taken into account. Both threshold type and maximum value type of decision schemes are also considered. The effects of several parameters, such as the number of time slots, the duty ratio, the extinction ratio, the count dimension, the signal-to-background radiation power ratio, and the signal-to-thermal noise power ratio are discussed in detail. The detection characteristic of this system are made clear by comparison with a pulse-position modulation system.