Showing papers on "Wavelength-division multiplexing published in 1981"
27 Apr 1981
TL;DR: Standard optical fiber communication systems employ intensity-modulation/direct-detection schemes, but some applications of optical Fiber communication exist in which a long repeater separation is the primary concern; an example is submarine optical cable communication between islands, in this case, the improvement of the bit-error rate (BER) by a coherent modulation/demodulation scheme such asPCM-PSK or PCM-FSK may be advantageous even at the sacrifice of simplicity and low cost.
Abstract: Standard optical fiber communication systems employ intensity-modulation/direct-detection schemes. This is noise-carrier communication and in a sense is more primitive than the radio engineering in Marconi’s age. However, it has the practical advantage of system simplicity and low cost. On the other hand, some applications of optical fiber communication exist in which a long repeater separation is the primary concern; an example is submarine optical cable communication between islands, in this case, the improvement of the bit-error rate (BER) by a coherent modulation/demodulation scheme such as PCM-PSK or PCM-FSK may be advantageous even at the sacrifice of simplicity and low cost.
72 citations
TL;DR: The theory, production process, and properties of wavelength division multiplexers (WDM) designed on the beam splitting principle are described.
Abstract: The theory, production process, and properties of wavelength division multiplexers (WDM) designed on the beam splitting principle are described. Typically these modules require no lenses, and the edge interference filter applied to the oblique polished single-mode or multimode fiber end face exhibits only minimal polarizing effects. Whereas all the fibers of multimode modules are identical in type, single-mode modules require a large-diameter core fiber for coupling out light. The characteristics of the couplers depend on the given type of fiber (single-mode or multimode), the light sources (laser diodes or LEDs), the channel separation, and the channel used (transmission or reflection). Insertion losses vary between 0.7 and 2 dB, far-end cross talk attenuation varies between 11 and 22 dB, and near-end cross talk attenuation exceeds 40 dB.
44 citations
TL;DR: In this article, two types of optical multi/demultiplexers using a single-mode fiber for a two-way transmission system were described, one consisting of four bandpass filters and a short wavelength pass filter or a long wavelength pass filtering.
Abstract: This paper describes two types of optical multi/demultiplexers using a single-mode fiber for a two-way transmission system. One type, the filter type, consists of four bandpass filters and a short wavelength pass filter or a long wavelength pass filter. The other, the filter-grating type, consists of two bandpass filters and a grating. The present multi/demultiplexers have four channels with 1.05, 1.15, 1.3, and 1.5 μm wavelengths. Total insertion losses are less than 2.3 and 3.2 dB for the filter type and the filter-grating type, respectively. Cross-talk between channels is less than -40 dB.
35 citations
TL;DR: A simple single-element holographic optical demultiplexer for wavelength division multiplexing in optical fiber systems is described and experimental results for a device operating in the visible region of the spectrum are described.
Abstract: A simple single-element holographic optical demultiplexer for wavelength division multiplexing in optical fiber systems is described. The single holographic element performs all the required functions of collection, separation, and focusing. Experimental results for a device operating in the visible region of the spectrum are described. The device is bidirectional and also functions as an efficient multiplexer.
24 citations
TL;DR: A basic bidirectional fibre optic loop-structured network configuration which provides an automatic recovery mechanism against a line failure and employs WDM-TDMA techniques for signal multiplexing is presented.
Abstract: A basic bidirectional fibre optic loop-structured network configuration which provides an automatic recovery mechanism against a line failure and employs WDM-TDMA techniques for signal multiplexing is presented. Experimental results of a prototype of such a network are also described.
20 citations
TL;DR: Experimental values for APD receiver sensitivity degradation in a system operating at a bit rate of 10 Mbits/s and at a wavelength of 830 nm were found to be within 2 to 3 dB (optical) of the values predicted by a simple theoretical model.
Abstract: Receiver sensitivity degradation caused by Rayleigh backscattering and coupler reflections is investigated for bidirectional digital transmission systems. Experimental values for APD receiver sensitivity degradation in a system operating at a bit rate of 10 Mbits/s and at a wavelength of 830 nm were found to be within 2 to 3 dB (optical) of the values predicted by a simple theoretical model.
17 citations
TL;DR: In this paper, the results of a WDM experiment involving the transmission of three video channels using AM-VSB modulation on each of three lasers in the 800-900 nm range are presented.
Abstract: The results of a WDM experiment involving the transmission of three video channels using AM-VSB modulation on each of three lasers in the 800-900 nm range are presented. A weighted video signal/noise ratio greater than 40 dB was achieved at each wavelength for a laser modulation index of 0.3 over a 1.1 km link.
16 citations
TL;DR: Bit-error-rate measurement values of <10(-9) prove the feasibility of optical fiber transmission at 5 Gbit/sec.
Abstract: A Gbit/sec optical fiber communication experiment was performed. The maximum speed was 3 Gbit/sec with a BH laser and 5 Gbits/sec with a TJS laser. A 500-m single-mode fiber was used, and the power was coupled by mounting the laser butt-end to the fiber, giving a minimum loss of 10 dB. The receiver employed a Si-avalanche photodiode with an impulse-response width of 210 psec (FWHM) and a 10-Gbit/sec and gate built from GaAs MESFETs. Bit-error-rate measurement values of <10−9 prove the feasibility of optical fiber transmission at 5 Gbit/sec.
14 citations
TL;DR: This paper will examine a series of experimental measurements made to determine the reflectance coefficients of several different end terminations and types of connection to demonstrate the sensitivity of full duplex fiber-optic telecommunication links to reflections.
Abstract: The signal-to-noise ratio of full duplex fiber-optic telecommunication links using a single fiber with directional couplers is shown to be extremely sensitive to reflections from fiber end terminations and fiber-to-fiber connections. This paper will examine a series of experimental measurements made to determine the reflectance coefficients of several different end terminations and types of connection.
13 citations
Patent•
24 Nov 1981TL;DR: In this article, the authors proposed a plesiochronous standard multiplexer (MUX C) for a digital optical subscriber network, comprising a broadband communications central unit and subscriber connection devices.
Abstract: Multiplex concept for a digital optical subscriber network, comprising a broadband communications central unit and subscriber connection devices. In the broadband communications central unit, the input bit flows O1 originating from the distributive services (15 TV channels) and the outgoing communications services (BiF), in each case with high bit rates, are each converted according to the invention, after passing through a plesiochronous standard multiplexer (MUX C), into a respective standard bit flow O1 with the central clock of the broadband communications central unit. These, for example, 16 standard bit flows are fed to a subscriber-individual distribution exchange (TV-VSt) in which the subscriber can select three standard bit flows simultaneously via a backward channel standardised with the incoming communications services (BiF, ISDN). In one of the three selectable standard bit flows, the input bit flow O2 leaving the low bit-rate communications services (ISDN) is inserted, following preceding frame identification, in the position of an unoccupied additional capacity ( DELTA O)2. The three selectable standard bit flows are present in a synchronous multiplexer (MUX A) and, in conjunction with a fourth standard bit flow with distributive services of low bit rate O3 and an additional capacity, produce the bit flow O4 (Fig. 1). In the subscriber connection device, the input bit flows O1, O2, and O3 are retrieved in corresponding reversal from the incoming bit flow O4 in a synchronous demultiplexer (DEMUX A), three standard demultiplexers (DEMUX C) connected downstream, a special plesiochronous demultiplexer (DEMUX C) and a special plesiochronous demultiplexer (DEMUX C'). The bit flows leaving the subscriber for high bit-rate (BiF) and low bit-rate (ISDN) communications services and the control signals (S1-S3) for selection of the standard bit flows are combined in a standard multiplexer and transmitted in wavelength division multiplexing to the broadband communications central unit.
10 citations
TL;DR: In this article, a new optical directional coupler using embedded singlemode glass waveguides is presented, which is compatible with single-mode fiber and is expected to be a useful component for future wavelength division multiplexing transmission systems.
Abstract: A new optical directional coupler using embedded single-mode glass waveguides is presented. The glass waveguides, called deposited silica waveguides (DS guides), were fabricated by depositing doped glass on a silica substrate after forming grooves by reactive sputter etching. Waveguide transmission loss was measured to be 1.3 dB/cm, and fiber-to-waveguide coupling loss was 0.1 dB. Using a tunable monochromatic light source, 96 percent power transfer or 14 dB isolation was measured. The DS guide directional coupler is compatible with single-mode fiber and is expected to be a useful component for future wavelength division multiplexing transmission systems.
TL;DR: In this article, a new method of designing dielectric edge filters for wavelength-selective optical tapping elements based on the beam splitter concept relies on the analysis of the envelope of the reflectance for the beam components oscillating normal and parallel to the plane of incidence in the passband of the filter.
Abstract: A new method of designing dielectric edge filters for wavelength-selective optical tapping elements based on the beam splitter concept relies on the analysis of the envelope of the reflectance for the beam components oscillating normal and parallel to the plane of incidence in the passband of the filter Despite the 45° angle of incidence of the beam, the strong polarizing effects usually encountered are almost entirely avoided for the two wavelengths that are to be demultiplexed A number of multilayer stack designs of the type S(H/2 L H/2) k S are described in which the ideal reflectance Rs = Rp = 0 is realized for the s and p components at the wavelength to be passed, while the desired value Rs≈Rp≈1 is realized for the wavelength to be rejected
29 Jul 1981
TL;DR: The Multiwavelength Monolithic Integrated Fiber Optic Terminal (MMIFOT) as mentioned in this paper was developed by MDAC-St. Louis for the NASA Johnson Space Center and used a single mode optical fiber for transmission between the terminals.
Abstract: This paper describes the Multiwavelength Monolithic Integrated Fiber Optic Terminal (MMIFOT) being developed by MDAC-St. Louis for the NASA Johnson Space Center. The program objective is to utilize guided wave optical technology to develop an optical wavelength multiplexing/demultiplexing unit using a single mode optical fiber for transmission between the terminals. Intensity modulated injection laser diodes, chirped diffraction gratings, thin film lenses and pin photodiodes are used to achieve the wavelength multiplexing and demultiplexing.© (1981) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: In this paper, the experimental results of a new multiplexer using light source polarisations for a wavelength division multiplexing (WDM) transmission system are described. But the results are limited to two channels in the 1.2 µm wavelength region and the insertion losses are not taking reflection losses of lenses into account.
Abstract: Experimental results of a new multiplexer using light source polarisations for a wavelength division multiplexing (WDM) transmission system are described. This multiplexer has 2 channels in the 1.2 µm wavelength region. Insertion losses not taking reflection losses of lenses into account are estimated to be less than 0.25 dB. This multiplexer is applicable only in laser diode systems.
TL;DR: In this paper, a simplified dual channel dual channel wavelength division multiplexed (WDM) system that uses a two-color LED and wavelength demultiplexing photodiode is tested.
Abstract: The simplified dual channel wavelength division multiplexed (WDM) system that uses a two-color LED and wavelength demultiplexing photodiode is tested. The total crosstalks at shorter (1.13 µm) and longer (1.36 µm) wavelength channels are -15 dB and -17 dB, respectively, which are determined by the spectral crossover of emission spectra of the LED and the spectral sensitivities of the photodetector. The possibility of the WDM system that does not need a "multiplexer" and "demultiplexer" is demonstrated in this letter.
IBM1
TL;DR: A single chip optical receiver circuit capable of operation at data rates of 200Mb with a NEP of 36dBm will be described.
Abstract: A single chip optical receiver circuit capable of operation at data rates of 200Mb with a NEP of 36dBm will be described. The circuit generates logic outputs directly from a PIN photodiode input.
TL;DR: The era of experi~ mental and trial installations appears to be near an end, and customers are ready for standard commercial offerings, but there remain certain pro,blems to be solved in such systems as ubscriber loops and long-haul and undersea transmission systems.
Abstract: n a recent Special Issue on Optical Fiber Communications (PROCEEDINGS OF THE IEEE, October 1980), S.E. Miller, the Guest Editor, said “ . . . The era of experi~ mental and trial installations appears to be near an end, and customers are ready for standard commercial offerings.” This is indeed the case for most of the optical fiber systems: short-haul and intraoffice systems, on-premises applications, data links, etc. However, there remain certain pro,blems to be solved in such systems as ubscriber loops and long-haul and undersea transmission systems. The long-haul system involves technical difficulties because it necessarily demands the use of single mode fibers. The optical undersea system ~~~ ~~ ~ ~~ ~~ ~~
01 Mar 1981
TL;DR: In this article, an evaluation of the different design techniques for WDM is provided, with heavy emphasis placed on the physical techniques for performing optical demultiplexing and future considerations for the design and implementation of WDM techniques in the fiber optic industry.
Abstract: : This report provides an evaluation of the different design techniques for Wavelength Division Multiplexing. Heavy emphasis is placed upon the physical techniques for performing optical demultiplexing. The report includes illustrations and data on different design components along with the pros and cons of each. Also included are future considerations for the design and implementation of Wavelength Division Multiplexing techniques in the fiber optic industry. (Author)
Journal Article•
TL;DR: This paper outlines the concept of a two-dimensional-grating multiplexer (and demultiplexer) and includes factors governing the design, test techniques, and experimental results derived after constructing such a system.
Abstract: The number of data points transmitted by an optical waveguide can be greatly increased by assigning one narrow wavelength region to each data point. The technique, called wavelength or spectral multiplexing, allows hundreds of data points to be transmitted simultaneously over a few fibers. This paper outlines the concept of a two-dimensional-grating multiplexer (and demultiplexer) and includes factors governing the design, test techniques, and experimental results derived after constructing such a system. This experimental system simultaneously transmits and reconstructs 5 x 10/sup 3/ high quality data points from a two-dimensional object through 50 fibers in a linear array. Information concerning resolution, system efficiency, distortion, wavelength range, and the selection of components is included.
Patent•
12 May 1981
TL;DR: In this paper, the authors proposed a method to enable wide band transmission characteristics to be obtained by using a core and a clad of a high refractice index difference and forming the core to an outside diameter corresponding to the difference.
Abstract: PURPOSE:To enable wide band transmission characteristics to be obtained by using a core and a clad of a high refractice index difference and forming the core to an outside diameter corresponding to the refractive index difference. CONSTITUTION:The refractive index n1 of the core 1 constituting an optical fiber and the refractive index n2 of a clad 2 show a high refractive index difference and when the radius from the center of the core 1 toward the outer side is shown as (r), these assume, for example, a step type distribution. With such constitution, the diameter 2a of the core 1 is made to correspond to the refractive index difference between the core 1 and the clad 2; for example, in a wide band including the wavelengths at which the transmission losses of a quartz optical fiber become minimum, the entire dispersion is made within + or -1ps/Km/nm, and this enables super wide band super long distance transmission to be performed by WDM (wavelength multiplexing).
25 Feb 1981
TL;DR: A novel application of an optically pumped half-ring laser to detect and regenerate multiplexed signals is suggested for the utilization of high-speed guided wave components to realize multiple-access data rates above 100 Mbits/s.
Abstract: A system is proposed for the utilization of high-speed guided wave components to realize multiple-access data rates above 100 Mbits/s. Angular division multiplexing is used to obtain parallel optical signal transmission and processing in routing data packets between host computers. A novel application of an optically pumped half-ring laser to detect and regenerate multiplexed signals is suggested.© (1981) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.