1. Field of the Invention
The present invention relates to a gas treatment of an optical fiber, and particularly relates to a gas treatment performed to improve a hydrogen-resistant characteristic of an optical fiber. More particularly, the present invention relates to an optical fiber processing apparatus and a process method performed by a gas including a deuterium.
2. Description of Related Art
An optical fiber most used in optical transmission line is a single mode optical fiber having a zero dispersion wavelength near 1310 nm. Conventionally, this optical fiber has been used for the transmission of a signal light of 1310 nm. However, these days the optical fiber is used to transmit a signal light having other wavelengths due to the advance of a dispersion compensation technique.
In recent years, there has been developed a CWDM (Coarse Wavelength Division Multiplexing) technique in order to comply with the increase of a transmission capacity to be requested at low cost. The transmission technique restrains the generation of crosstalk between each signal wavelength by broadening a wavelength interval to about 25 nm even if a cheap light source is used. In order to transmit much signal light using an optical fiber in the technique, it is desirable that a usable wavelength region is wide. However, in a conventional single mode optical fiber, there is an absorption loss peak (hereinafter, referred to as an OH peak) caused by an OH group in an optical fiber near 1383 nm. This wavelength region cannot be utilized. In order to use this region, a low water peak optical fiber is developed, and is prescribed as an International Standard in ITU-T G652 table C.
Such an optical fiber initially requires a small OH peak and also requires a small OH peak after aging by hydrogen. For this reason, there is a method for processing an optical fiber in deuterium as one method improving a hydrogen-resistant characteristic of an optical fiber. This method is a method having a characteristic that deuterium D reacts to a defect in an optical fiber in the same way as that of hydrogen H and yet an OD group does not cause an absorption loss peak in a wavelength area used as signal light because the OD group is different from an OH group. See, for example, a Japanese Patent Application publication No. 60-90852, a Japanese Patent Application Publication No. 7-277770 and a Japanese Patent Application Publication No. 2000-148450.
A process of an optical fiber by deuterium as described above is performed for predetermined time in a state where an optical fiber is put in a container that can be sealed and the container is filled with deuterium to form an atmosphere containing deuterium. Since the deuterium is combustible gas similarly to hydrogen, the atmosphere in the container should be displaced with inert gas or the like such as nitrogen safely enough before filling with an atmosphere containing deuterium.
Conventionally, a treatment container has been grown in size to process a large quantity of optical fiber. However, when a container grows in size, it takes time to displace components in the container with inert gas and fill with an atmosphere containing deuterium. A conventional apparatus is shown in
In consideration of the problem, an object of the present invention is to provide an optical fiber processing apparatus and a process method capable of shortening time required for replacing an atmosphere in a treatment container with inert gas and filling with deuterium and of restraining an amount used of expensive deuterium.
The optical fiber processing apparatus of the present invention includes a plurality of containers for processing optical fiber that are spatially coupled by piping, each treatment container including a treatment chamber that can be sealed and accommodate one or more bobbins on which fiber to be processed is wound, in which the treatment chamber is supplied with treatment gas, and the optical fiber is processed by the gas. The treatment gas may be deuterium or gas including deuterium.
In the optical fiber processing apparatus, the treatment container may arrange and accommodate the plurality of bobbins on a line in the axial direction in which the optical fiber is wound. Further, in the optical fiber processing apparatus, a cross section of the treatment chamber of the treatment container perpendicular to the direction in which the bobbins are arranged may have substantially the same magnitude in size as a cross section of the bobbins.
In the optical fiber processing apparatus, the treatment container may have a transparent window through which whether the bobbins are accommodated in the treatment chamber can be comprehended from the outside. Further, in the optical fiber processing apparatus, the window may lengthwise be arranged in the direction in which the bobbins in the treatment container are arranged.
The optical fiber processing apparatus may further include a detecting section that detects whether the bobbins are accommodated in the treatment chamber of the treatment container. Further, in the optical fiber processing apparatus, the detecting section may include a scale that measures weight of the treatment container.
The treatment container according to the present invention may have a tubular shape of which one end has a door which can be opened or closed, a cross sectional shape of the treatment container may have a circle or a shape similar to the circle, and the treatment chamber of the treatment container may include a slidable tray therein. The treatment containers may be connected to one another by piping to be exhausted by a vacuum pump, the optical fiber processing apparatus may further include valves that are provided in the piping for coupling the plurality of treatment containers, in which some of the plurality of treatment containers are freely disconnected from or connected to other treatment containers and an air supply and exhaust system by the valves, and the optical fiber processing apparatus may further include a system that controls and manages a gas process for the optical fiber in each treatment container in an integrated fashion.
In addition, a method for processing optical fiber according to the present invention uses the optical fiber processing apparatus.
The summary of the invention does not necessarily describe all necessary features of the present invention. The present invention may also be a sub-combination of the features described above.
According to an optical fiber processing apparatus and a process method of the present invention, it is possible to process a plurality of treatment containers under a gas atmosphere individually or in combination with one another using some containers depending on the number of bobbins on which fiber be processed is wound. Since time required for processing fiber decreases and required amount of deuterium decreases, a process cost is significantly reduced. Furthermore, it is possible to control and manage a gas process for optical fiber in each treatment container and thus reduce the required workforce.
The invention will now be described based on the preferred embodiments, which do not intend to limit the scope of the present invention, but exemplify the invention. All of the features and the combinations thereof described in the embodiment are not necessarily essential to the invention.
As a result of a repeated keen examination, the present invention can have a treatment container configuration suited to an amount of fiber to be processed using treatment containers individually or in combination with one another, by spatially coupling the plurality of independent treatment containers, which can respectively accommodate a few bobbins, by means of piping and disconnecting and connecting the containers from/to one another using the arrangement of valves. Hereinafter, it will specifically be described based on an embodiment.
Moreover, as shown in
In addition, the door 7, the valve 2, the flow controller (MFC), and the vacuum pump for exhaust 3 in the treatment container 1 are controlled and managed in an integrated fashion by means of a control unit not shown, in order to perform a gas treatment. In this manner, since a state of each treatment container is controlled and managed in an integrated fashion, there are performed, without fail, elapsed time for treatment in each treatment container, an atmosphere in the treatment container, opening and closing of the treatment container, disconnecting and connecting of each treatment container from/to a gas supply and exhaust system, and so on.
Moreover, the optical fiber processing apparatus may include a scale for measuring weight of the treatment container 1 in place of the window 10 or in addition to the window 10 shown in
When processing optical fiber using gas, e.g., under an atmosphere including deuterium of 1% at normal temperature and pressure, the treatment of optical fiber requires three and half days. However, since the optical fiber is drawn and accumulated during this period, it is preferable that the deuterium treatment of the optical fiber is performed in parallel with the drawing. When using the processing apparatus according to the present invention in such a situation, some treatment containers are filled with an atmosphere containing deuterium and is under a processed state, and other treatment containers takes out and puts in the optical fiber, exhausts treatment gas, and introduces gas. In this way, gas treatments in various process steps are performed in parallel.
Although the present invention has been described by way of an exemplary embodiment, it should be understood that those skilled in the art might make many changes and substitutions without departing from the spirit and the scope of the present invention. It is obvious from the definition of the appended claims that embodiments with such modifications also belong to the scope of the present invention.
An optical fiber processing apparatus and a process method of the present invention can apply optical fiber to various gas treatments in a state that the optical fiber is wound on a bobbin, in addition to a gas treatment performed to improve a hydrogen-resistant characteristic of the optical fiber.
Number | Date | Country | Kind |
---|---|---|---|
2003-271859 | Jul 2003 | JP | national |
The present application is a continuation application of PCT/JP04/9666 filed on Jul. 7, 2004, which claims priority from a Japanese Patent application No. 2003-271859 filed on Jul. 8, 2003, the entire contents of which are incorporated herein by reference for all purposes.
Number | Date | Country | |
---|---|---|---|
Parent | PCT/JP04/09666 | Jul 2004 | US |
Child | 11326352 | Jan 2006 | US |