摘要:
An optical privacy communication system in optical fiber communications between many points is disclosed in which, each station is provided with a privacy circuit. Each privacy circuit comprises a first optical branch for connecting the station to first and second optical branches, a second optical branch for connecting the first and second optical branches to the optical fiber transmission line, an optical isolator inserted in the first optical branch, for passing only a signal of a direction from the first optical branch to the second optical branch, and an optical filter inserted in the second optical branch, for passing only an optical signal of a frequency assigned to the station, so that an optical privacy communication is carried out between the stations.
摘要:
An optical amplification method or system for an optical communication system which transmits signal light from the transmitting side to the receiving side via an optical transmission medium formed by an optical fiber or space. In accordance with the present invention, the signal light entered a certain state of polarization in at least one part of the transmitting side, the receiving side and the optical transmission medium is separated into two orthogonal polarized waves by a polarizing beam coupler/splitter. The two polarized waves are amplified by optical amplifiers disposed in correspondence to their state of polarization, respectively. The amplified orthogonal polarized waves are combined together by another polarizing beam coupler/splitter.
摘要:
A signal coupler couples more than three transmitter-receivers through optical fiber cables and at least one repeater on a bit-multiplex system, by exchanging or reallocating each time slot according to a transmission station and the related destination. The coupler has a means to release the bit-multiplexing (or demultiplex) the signals from each transmitter by deriving the control clock signals from the information signals themselves. The coupler also has a means for multiplexing the bit signals for each destination by automatically adjusting the phase relationships among the released signals (demultiplexed signals) for bit-synchronization using a delay circuit.
摘要:
A multi-point optical amplification repeating system is disclosed in which an output of a unidirectional amplifier inserted in a unidirectional repeating optical transmission system is branched and coupled to an input of a unidirectional amplifier inserted in another unidirectional repeating optical transmission system, so that bidirectional optical communication can be performed between many points connected to a plurality of first optical transmission lines. If a bidirectional amplifier is employed in a bidirectional repeating optical transmission system, the above bidirectional optical communication can be also realized by fed back the first port of the bidirectional amplifier to the second port thereof through an optical isolator.
摘要:
A rotary joint for optical fibers consists of two rotary members which enable efficient transmission of optical signals without the need of converting the same into electric signals by attaching rod lenses having a refractive index in the second order distribution relative to its center axis, to respective tips of the optical fibers capable of relative rotation so that an optical signal emitted from the tip of one optical fiber is transmitted from the end of one rod lens in the form of parallel rays to the other rod lens, and as a converged beam to the tip of the other optical fiber. The joint further includes a mechanism for imparting pressure to the rotary members, and a mechanism for finely setting the angle between the two rod lenses.
摘要:
Delay time variation in an optical fiber digital communication system which includes optical regenerative repeaters is measured at one of terminal ends having reference clock signal. A monitor signal which depends upon the delay time variation is provided at the farthest repeater in an area where delay time is subject to secular change by dividing reference clock signal from said terminal end, and said monitor signal is returned to the terminal end from said farthest repeater, and the terminal end compares the returned monitor signal with the divided reference signal by using a phase comparator to provide measure of delay time variation.
摘要:
A device for burying a submarine cable under the water by easily and accurately detecting the cable position and a method for guiding the same by utilizing the characteristics unique to submarine cables, by supplying an AC only to the portion of the cable between two arbitrary repeaters through a so-called transformer-coupling system to generate an AC magnetic field, and by detecting the magnetic field with a magnetic field detector.
摘要:
The present invention has an object to provide an underwater cable burying device which can accurately be guided to align with the cables in the process of burying even if the cables have to be re-buried. The device according to the present invention is characterized in that a travelling device is provided on the body of the device which is further provided with a trenching device at the middle portion thereof, that a cable clamp member and a cable engaging member are provided at an arm projecting forward from the said device body and that said respective devices are controlled through a control cable on the mother ship.
摘要:
The problems in accordance with the present invention are: to provide a DLC film, wherein a protective film having a segmented shape is easily formed, quality control of the protective film is improved, segmented shapes with a high degree of freedom (that are complicated) are possible, and the application of the DLC film is possible not only to two-dimensional shapes but also to three-dimensional shapes; and to provide a method for forming the DLC film. As solutions to the problems, there are provided a protective film and a method for producing the protective film, characterized by, when forming on a substrate the protective film having a segmented shape formed by depositing a film so that the film is formed divided into segments, masking the substrate using a drawing material so that segments having predetermined shapes are obtained, thereafter depositing the protective film, and then removing the masked part to form a spacing between segments.
摘要:
The present invention relates to a diamond-like carbon film forming apparatus and a method of forming a diamond-like carbon film.A diamond-like carbon film forming apparatus using plasma chemical vapor deposition of the present invention is provided with a member (4) comprised of a substrate (2) surrounded by a conductive mask material (3) and a DC single pulse power supply (6) and superimposition DC power supply (26) and/or high frequency power supply (7) for supplying power voltage with the wall of the chamber (5) of the diamond-like carbon film forming apparatus, which apparatus selects and applies to the member (4) either a negative single pulse voltage from the DC single pulse power supply (6) and said superimposition DC power supply (26) or a high frequency voltage of the high frequency power supply (7) so as to form a segment structure diamond-like carbon film on the substrate (2) surrounded by the mask material (3).