Showing papers on "Insertion loss published in 1986"
TL;DR: In this article, a strictly nonlocking 8×8 integrated optics switch matrix in Ti: LiNbO3 was presented, which consisted of 64 directional couplers on one chip.
Abstract: We report on a strictly nonlocking 8×8 integrated optics switch matrix in Ti: LiNbO3. The matrix comprises 64 directional couplers on one chip. Insertion losses less than 7 dB have been measured. The extinction ratio has an average value of 30.5 dB for the directional couplers.
107 citations
01 Jan 1986
100 citations
TL;DR: In this article, an electroabsorption (EA) light modulator (LM) with a strip-loaded GaInAsP planar waveguide has been described, and a 3dB bandwidth of 3.8 GHz has been achieved and a pulse modulation operation under 2 Gbit/s nonreturn-to-zero (NRZ) pseudorandom pattern has also been confirmed.
Abstract: We describe fabrication and characterization of an electroabsorption (EA) light modulator (LM) with a strip-loaded GaInAsP planar waveguide. The EA LM's were fabricated from hydride vapor-phase-epitaxy (VPE) grown wafers. The electroabsorption, the insertion loss, the electrical properties, and the modulation characteristics were investigated for the EA LM's. The drive voltage at a 99-percent modulation depth has been noticeably reduced to 4.5 V by optimizing the thicknesses of the epitaxial layers. The total capacitance of 1.5 pF was obtained by inserting an insulating film under the wire-bonding pad and by improving the mount design. Consequently, a 3-dB bandwidth of 3.8 GHz has been achieved and a pulse modulation operation under 2 Gbit/s nonreturn-to-zero (NRZ) pseudorandom pattern has also been confirmed. Moreover, the dynamic spectra of the EA modulators were measured for the first time. A spectral broadening factor α has been determined to be 1-4 from a relative strength of the sideband to the carrier and it has been experimentally found to decrease with increasing the electric field inside the absorptive waveguide. As the other measures of merit for the EA LM's, the extinction ratio over 23 dB and the insertion loss of 10-14 dB including a coupling loss due to an end-fire method were obtained. As a whole, these results have exhibited that the EA LM is a promising external modulator which will be monolithically integrated into a gigabit per second optical source with a dynamic single-mode laser.
88 citations
TL;DR: In this article, a simple architecture for bidirectional optical fiber transmission using an MQW device as both modulator and photodetector was proposed, which achieved transmission of 50 Mbit/s and 600 M bit/s in both directions over one 3.34 km-long single-mode fiber at 860 nm wavelength.
Abstract: We demonstrate a simple architecture for bidirectional optical fibre transmission which uses an MQW device as both modulator and photodetector. We achieved transmission of 50 Mbit/s and 600 Mbit/s in both directions over one 3.34 km-long single-mode fibre at 860 nm wavelength. Coherent Rayleigh interference was found to be a limiting factor in single-source bidirectional systems.
67 citations
TL;DR: Several low crosstalk 4 × 4 crossbar optical switch arrays have been fabricated for use at λ = 1.3 \mu m as mentioned in this paper, each array consists of 16 independently functioning directional coupler switches and the average insertion loss is 5.2 dB.
Abstract: Several low crosstalk 4 × 4 crossbar optical switch arrays have been fabricated for use at \lambda = 1.3 \mu m. Each array consists of 16 independently functioning directional coupler switches. We describe the typical device performance characteristics. The average insertion loss is 5.2 dB. Crosstalk levels routinely measured < -35 dB. The voltage required to operate the device is ≈ 13 V. The inputs to one of the device arrays were permanently attached to four laser transmitters using lensed polarization maintaining fiber at the laser end and an array of polarization maintaining fibers at the device end.
56 citations
TL;DR: A metal-clad fiber-optic cutoff polarizer using a thin film is proposed and fabricated and an extinction ratio of 47 dB with excess loss of 1 dB in the polarizer has been achieved.
Abstract: A metal-clad fiber-optic cutoff polarizer using a thin film is proposed and fabricated. An extinction ratio of 47 dB with excess loss of 1 dB in the polarizer has been achieved.
55 citations
TL;DR: In this article, the minimum absorption coefficient, which determines the absorption component of the device insertion loss, has been measured using a new measurement technique, and determined that, for a device with a 10:1 on/off ratio and a 7 dB insertion losses, absorption contributes 2.2 dB of the insertion loss.
Abstract: Although large changes in the absorption coefficient of multiple quantum wells (MQW’s) with applied voltage have been reported, no accurate measurement of the minimum absorption coefficient, which determines the absorption component of the device insertion loss, has been reported. Using a new measurement technique, we measure this minimum absorption coefficient, and determine that, for a device with a 10:1 on/off ratio and a 7 dB insertion loss, absorption contributes 2.2 dB of the insertion loss. We are able to predict absorption losses of future devices and show that, by a slight change in operating wavelength, the absorption loss can be greatly reduced.
54 citations
TL;DR: A novel concept for a digital optical position transducer that is electrically passive and requires only a dual-fiber optical link and has a 10-dB on–off contrast ratio and a 12-dB insertion loss.
Abstract: A novel concept for a digital optical position tranducer is presented. This compact and rugged device is electrically passive and requires only a dual-fiber optical link. Wavelength division of a broad-spectrum semiconductor light source is employed to multiplex the channels of a 10-bit digital position encoder. A preliminary design was evaluated and found to have a 10-dB on-off contrast ratio and a 12-dB insertion loss.
46 citations
TL;DR: An in-line polarizer has been demonstrated that uses the birefringent properties of a nematic liquid crystal placed in the evanescent field of a single-mode fiber to polarize the liquid-crystal molecules.
Abstract: An in-line polarizer has been demonstrated that uses the birefringent properties of a nematic liquid crystal placed in the evanescent field of a single-mode fiber. A polarization-extinction ratio of 45 dB was measured with an insertion loss of 1.1 dB. Amplitude modulation was also demonstrated by using an external electric field to reorient the liquid-crystal molecules.
46 citations
TL;DR: In this paper, continuous metal/glass fiber polarisers incorporating Ga or In/Sn alloy have been fabricated and an extinction ratio of greater than 37dB with an insertion loss of less than 1 dB can be obtained over a 250nm spectral window around 1300nm.
Abstract: Continuous metal/glass fibre polarisers incorporating Ga or In/Sn alloy have been fabricated. An extinction ratio of greater than 37dB with an insertion loss of less than 1 dB can be obtained over a 250nm spectral window around 1300nm. Extinction ratios as high as 52dB have been measured at 830 nm.
42 citations
TL;DR: In this article, the authors reported the optimization of Ti:LiNbO 3 optical waveguides and directional coupler switches for the 1.56 μm wavelength, achieving total fiber-coupled insertion loss as low as 2.2 dB.
Abstract: We report the optimization of Ti:LiNbO 3 optical waveguides and directional coupler switches for the 1.56 μm wavelength. Total fiber-coupled insertion loss as low as 2.2 dB was achieved with diffusion conditions allowing a low switching voltage in Ti : LiNbO 3 directional coupler switches.
TL;DR: In this article, a fibrepigtailed, broadband travelling-wave X-cut Ti:LiNbO3 phase modulator for λ = 1.55 μm with 1.8 dB total insertion loss and 8 V modulation voltage was presented.
Abstract: We report the design, fabrication and performance of a fibrepigtailed, broadband travelling-wave X-cut Ti:LiNbO3 phase modulator for λ = 1.55 μm with 1.8 dB total insertion loss and 8 V modulation voltage.
Patent•
13 Jan 1986TL;DR: In this article, a combination optical time domain reflectometer (OTDR) and insertion loss measurement system is used to evaluate the environmental stress effects on a test fiberoptic cable.
Abstract: A combination optical time domain reflectometer (OTDR) and insertion loss measurement system evaluates environmental stress effects on a test fiberoptic cable. A multiport coupler joins the OTDR and insertion loss system to the test fiberoptic cable via a precursor of like type and length with respect to the test cable. Nondestructive analysis, continuously and throughout, measures attenuation between any two points within the equilibrium region of the test cable, the quality of the splice between the precursor and the test cable and the degree of EMD disruption. Attenuation measurements over operating environmental conditions can be made to precisely determine the maximum allowable cable length. Visual readouts and permanent records of the EMD disruption and resultant excess attenuation provide real time analysis so that responsive corrective actions can be made.
TL;DR: A directional coupler optical switch with good switching characteristics and low-loss guiding properties and high speed operation of 1.6 GHz was achieved.
Abstract: A directional coupler optical switch with good switching characteristics (extinction ratio of more than 22 dB at 22.5-V applied voltage) and low-loss guiding properties (total insertion loss of 10.7 dB including Fresnel reflection loss of 4.0 dB) has been developed. The switch element was mounted on a ceramic stem and jointed directly with polarization-maintaining optical fibers. High speed operation of 1.6 GHz was achieved.
02 Jun 1986
TL;DR: In this article, a 19-way waveguide isolated power divider with broad bandwidth, low insertion loss and high isolation was developed for an antenna array with a flexible number of output ports and uneven power distribution.
Abstract: A 19-way waveguide isolated power divider has been developed with broad bandwidth, low insertion loss and high isolation. Its design allows a flexible number of output ports and uneven power distribution. It can be used as a feed network for an antenna array and, due to this power divider's high isolation characteristics, it can be used as a power combiner for a high power amplifier.
TL;DR: In this article, a singlemode PC connector with spherically convex-polished ends, whose fibre ends make close contact, has been developed, which features extremely low insertion and high return-loss characteristics, and is also easily produced with good environmental performance.
Abstract: PC connectors with spherically convex-polished ends, whose fibre ends make close contact, have recently been developed. This connector features extremely low insertion-and high return-loss characteristics, and is also easily produced with good environmental performance. For a single-mode PC connector, the average insertion loss is measured to be as small as 0.17 dB with a return loss of 28 dB. Detailed evaluation of this connector is now under way for use in a trial optical transmission system.
TL;DR: In this article, the insertion loss between pairs of thin, linear antennas may be calculated using fairly simple equations that are generally considered to be good engineering approximations, and a close agreement between measured and calculated data provides confidence in the site attenuation calculations when the site is essentially perfect.
Abstract: It is demonstrated that the insertion loss between pairs of thin, linear antennas may be calculated using fairly simple equations that are generally considered to be good engineering approximations. Although the insertion loss calculation does not involve antenna gain directly (some measurements are actually made in the near-field where gain is not defined), the result is precisely the quantity obtained using the antenna gains in Friis's transmission formula, assuming the mismatch losses are zero. Therefore, the antenna gain product is implicit in the more general insertion loss equations. The particular measurement of insertion loss used here yields a quantity called site attenuation by electromagnetic compatibility engineers. A close agreement between measured and calculated data provides confidence in the site attenuation calculations when the site is essentially perfect, and provides confidence in the gain product of the antenna pair calculated using basically the same equations as those used for insertion loss. It is assumed that one-half of the mean value of the difference between the calculated and measured data is a good estimate of individual antenna performance. For the antennas described here, this measure of performance is typically \lE0.05 dB and on the outside, \iE0.42 dB.
TL;DR: In this paper, a temperature-stable bulk-acoustic-wave (BAW) filter consisting of a thin ZnO/SiO2 composite diaphragm structure on a silicon wafer is presented.
Abstract: This paper reports on a temperature-stable bulk-acoustic-wave (BAW) filter consisting of a thin ZnO/SiO2 composite diaphragm structure on a silicon wafer. To make a theoretical treatment of the BAW filter possible, the constants for the distributed-parameter equivalent circuit extended to the composite structure are derived from analysis of the dispersion curves for waves propagating along the ZnO/SiO2 diaphragm. Some actual filters are designed and analysed using the equivalent circuit. The measured characteristics of a 578-MHz BAW filter of the two-coupled-resonator type fabricated on silicon are reported and discussed. The results demonstrate that the measured characteristics resemble the theoretical ones but that the insertion loss is as high as 12 dB.
01 Jan 1986
TL;DR: In this paper, the TFR SCF (stacked crystal filter) configurations are reported including device performance, modeling, design, and materials requirements, and both Si-and GaAs-substrate-based filters are reported with GaAs receiving increased emphasis for microwave integrated circuit applications.
Abstract: Progress on the TFR SCF (stacked crystal filter) configurations is reported including device performance, modeling, design, and materials requirements. Both Si- and GaAs-substrate-based filters are reported with GaAs receiving increased emphasis for microwave integrated circuit applications. The experimental results reported are the result of a number of device feasibility studies done in the course of developing the technology toward its fully integrated form. Filters having insertion losses less than 1.6 dB, with two pole equivalent responses, have been demonstrated at frequencies between 1 and 2 GHz. These filters, using aluminum nitride as the piezoelectric, are approximately 1 mm/sup 2/ in area and designed for a 50- Omega impedance level. >
TL;DR: An algorithm is developed and validated for the prediction of the reduction, or degradation, of traffic noise barrier insertion loss when a second barrier is placed on the opposite side of the highway.
Abstract: An algorithm is developed and validated for the prediction of the reduction, or degradation, of traffic noise barrier insertion loss when a second barrier is placed on the opposite side of the highway. The algorithm combines the basic emission, propagation, and barrier attenuation features of the Federal Highway Administration traffic noise prediction model with a geometrical acoustics approach for multiple reflections. The resultant model can accommodate any number of source lanes or receivers, three vehicle categories, and independently variable barrier heights and absorption coefficients. The model was validated against mathematical, scale model, and full scale field data received from other researchers, and has proved to be a good predictor of insertion loss degradation.
TL;DR: In this paper, the authors investigated the potential of the Gires-Tournois interferometer as a means of providing adjustable group velocity dispersion, both intracavity and extracavity, in a configuration which is of low insertion loss, compact, highly tunable and insensitive to wavelength or polarisation.
01 Jan 1986
TL;DR: Different types of SAW-fiLters on quartz for timing recovery at frequencies up to 2 GHz have been designed and fabricated in this article, which are characterized by periodic structures and good suppression of reflection at the center frequency.
Abstract: Different types of SAW-fiLters on quartz for timing recovery at frequencies up to 2 GHz have been designed and fabricated. Because of the good compromise between Low insertion Loss and smaLL temperature coefficient the RayLeigh-wave has been used. The fiLters have been produced with a standard photoLithographic process with projection printing and Liftoff technique. To achieve center frequencies above 1 GHz the filters have to operate at higher harmonics. Methods for the synthesis and the anaLysis of these fiLters have been developed. The fabricated fiLters are characterized by periodic structures and good suppression of reflection at the center frequency. The reproducibiLity of the center frequencies is comparabLe to that of fiLters operating beLow 1 GHz.
TL;DR: In this paper, a gain factor is introduced in a characteristic transfer function representing a line and stub network, and a redundant form of this network is identified with the equivalent circuit of the edge-coupled line pair.
Abstract: Distributed element synthesis is used for obtaining edge-coupled-line impedance transformers. A gain factor is introduced in a characteristic transfer function representing a line and stub network. A redundant form of this network is identified with the equivalent circuit of the edge-coupled line pair. The transfer function is then used to synthesize Butterworth and Chebyshev coupled-line transformers. Design tables are presented for the symmetrical transformer. Transformation ratios different from unity are obtained only if the symmetrical structure is reflective. Asymmetrical transformers may exhibit nonunitary transformation ratios while being perfectly matched. Finally, applicability range is discussed.
TL;DR: A high-frequency switch utilizing a GaAs FET as an analog switch is expected to operate in a broad band and can be integrated in a monolithic IC form and is useful in the area where a small size and low power consumption are required.
Abstract: A high-frequency switch utilizing a GaAs FET as an analog switch is expected to operate in a broad band and can be integrated in a monolithic IC form. Since only a single power supply is needed for the gate bias and the power consumption of the switch can be made zero, it is useful in the area where a small size and low power consumption are required. To investigate the feasibility of a broadband GaAs monolithic switch, this paper first derives an equivalent circuit of the switch from the structural model of the FET and the relation between the switch characteristics and the device parameters of the FET. The design method of the switch is then developed. Next, the monolithic switches of SPDT and DPDT structures are fabricated by ion-implantation technology and their characteristics are evaluated so that the validity of the equivalent circuit model is confirmed. The GaAs monolithic SPDT switch realized has the passband of dc to 3.3 GHz, insertion loss less than 0.7 dB (dc to 2 GHz), isolation more than 20 dB, switching time 2 ns and the maximum distortionless signal input power 20 dBm. Similarly, good performance has been obtained for the DPDT switch.
02 Jun 1986
TL;DR: In this article, a planar power combiner/divider was developed for ultra-broadband MMIC applications utilizing Dolph-Tchebycheff transmission line taper.
Abstract: A new N-way broadband planar power combiner/ divider was developed for ultra-broadband MMIC applications utilizing Dolph-Tchebycheff transmission line taper. The combiner/divider demonstrated a 5 to 18 GHz bandwidth with an insertion loss of less than 0.2 dB and an input VSWR of no more than 1.35.
TL;DR: In this article, a singlemode fiber-optic wavelength division multiplexer/demultiplexer with excellent isolation is reported, which uses a fused biconical structure similar to that of 3 dB couplers and exhibits an insertion loss of 0.04 dB.
Abstract: A single-mode fibre-optic wavelength-division multiplexer/demultiplexer with excellent isolation is reported. The device utilises a fused biconical structure similar to that of 3 dB couplers and exhibits an insertion loss of 0.04 dB and a wavelength isolation of 43 dB at 1.300 ?m and 30 dB at 1.523 ?m.
TL;DR: In this article, a 30 GHz monolithic integrated circuits have been developed to make a 30GHz receiver with a low-noise amplifier, an IF amplifier, a mixer, and a phase shifter.
Abstract: Several monolithic integrated circuits have been developed to make a 30-GHz receiver. The receiver components include a low-noise amplifier, an IF amplifier, a mixer, and a phase shifter. The LNA has a 7-dB noise figure with over 17 dB of associated gain. The IF amplifier has a 13-dB gain with a 30-dB control range. The mixer has a conversion loss of 10.5 dB. The phase shifter has a 180° phase shift control and a minimum insertion loss of 1.6 dB.
TL;DR: In this article, the insertion loss of side-wall add-on acoustic treatments was measured using a light aircraft fuselage, including no treatment, a production-type double-wall interior, and various amounts of high-density fiberglass added to the baseline fuselage.
Abstract: The insertion loss of side-wall add-on acoustic treatments was measured using a light aircraft fuselage. The treatments included: no treatment (i.e., baseline fuselage), a production-type double-wall interior, and various amounts of high-density fiberglass added to the baseline fuselage. The source used to simulate propeller noise was a pneumatic-driver with attached exponential horn, supplied with a broadband signal. Data were acquired at the approximate head location for each of the six possible passenger positions. Insertion loss results for the different configurations were analyzed in space-averaged narrowband levels, one-third-octave band levels, and overall levels, and at specific frequencies representing propeller tone spectra. The propeller tone data include not only the space-averaged insertion loss but also the variation of insertion loss of these particular frequencies across the six microphone positions.
TL;DR: In this article, the fabrication and performance of a low-loss 8×8 star coupler from a network of four-port wavelength-flattened fused couplers is described.
Abstract: The letter reports the fabrication and performance of a low-loss 8×8 star coupler from a network of four-port wavelength-flattened fused couplers. The coupler insertion loss has a much reduced wavelength dependence compared to stars made from standard fused couplers, and provides a useful operating window from 1.2 to 1.6 μm.
TL;DR: In this article, the effect of high optical power levels, at a wavelength of 1.51 μn, on the characteristics of LiNbO3 Mach-Zehnder waveguide modulators is reported.
Abstract: A study of the effect of high optical power levels, at a wavelength of 1.51 μn, on the characteristics of LiNbO3 Mach—Zehnder waveguide modulators is reported. It is shown that the important modulator parameters, i.e. optical phase bias, extinction ratio, insertion loss and switching voltage, are stable for waveguide powers of <75 mW.