Sumitomo Electric Industries, Limited

Osamu Kasuu

Motonori Nakamura

Tomomi Sano

Yuichi Ohga

Tomomi Moriya

Shinji Kayou

Atsushi Inoue

Eisuke Sasaoka

Masaaki Hirano

Masashi Onishi

Daisuke Yokota

Toru Adachi

Shuichiro Kato

A core rod is inserted into a cladding pipe, moisture in a space between the core rod and the cladding pipe is removed, and an optical fiber is drawn while the space is connected to a dry-gas atmosphere and/or being decompressed and while the core rod and the cladding pipe are being unified with each other. Alternatively, the core rod is inserted into the cladding pipe, and an optical fiber is drawn from one end while moisture on the surface of the core rod and the internal surface of the cladding pipe is being removed. Accordingly, a high quality optical fiber is manufactured with good productivity.

Optical fiber and manufacturing method thereof

An object is to provide an optical fiber fusion splicing method in which splice loss can be reduced, and also to provide an arc-heating unit used for heating the fusion spliced part of an optical fiber. The method comprises a process of fusion-splicing together the end faces of two optical fibers and a process of continuously heating the fusion spliced part by arc while moving one pair of electrodes provided opposite to each other across the fusion spliced part. The arc heating process is performed with the operation for decreasing arc temperature. The operation for decreasing arc temperature may be achieved by flowing a gas having a molecular weight greater than the average molecular weight of air into a gas atmosphere in which arc heating is performed, or by adding a modulation to an electric discharge current such that the maximum value becomes equal to or more than an electric current for starting arc discharge and the minimum value becomes more than zero and less than the electric current for starting arc discharge.

Method for fusion splicing optical fibers and apparatus for heating spliced part by arc

A method of fusion-splicing optical fibers having different mode field diameters or small mode field diameters is provided, which method is advantageous in that the splicing loss is smaller. The method comprises a fusion splicing process in which fusion splicing is performed by butting end faces of two optical fibers together and a heat treatment process in which the fusion spliced part of the optical fibers and the vicinity thereof are heated. The heat treatment process is performed by moving an arc heating unit in a direction other than the Y-axis direction (a direction perpendicular to the Z-axis direction and the opposing direction of arc electrodes) and Z-axis direction (the axial direction of the optical fiber), via the fusion spliced part in a Y-Z plane formed by the Y-axis direction and Z-axis direction.

Method for fusion splicing of optical fibers

An optical fiber splicing method capable of fully reducing the splice loss at room temperature is provided. In the optical fiber splicing method in accordance with the present invention, respective end faces of optical fibers are fused together in a splicing step (S ). In a condition setting step (S ), a set value &agr; is set. Thereafter, a heating step (S ), a measuring step (S ), and a termination determining step (S ) are carried out repeatedly. In the heating step, a region including the fusion-spliced point is heated under a predetermined heating condition. In the measuring step, splice loss is measured. In the termination determining step, the splice loss &agr; measured in the measuring step and the set value &agr; set in the condition setting step are compared with each other in terms of magnitude. If the splice loss &agr; is not greater than the set value &agr; , then it is determined that the alternation should be terminated, whereby the optical fiber connecting operation is terminated.

Optical fiber splicing method and optical fiber

Methods for connecting two optical fibers having different mode field diameters ((MFD) with low connection loss is proposed. One method comprises steps of preparing the third fiber (Fiber ), a short length and MFD being smaller than that of the first fiber (Fiber ) and larger than that of the second (Fiber ), connecting the Fiber to connecting Fiber to and increasing MFD of Fiber near the part connected or to be connected to Fiber or MFD of Fiber near the part connected or to be connected to Fiber by heating the corresponding part. The other method comprises steps of preparing a short length Fiber having smaller MFD than that of Fiber increasing MFD of Fiber near the part to be connected to Fiber by heating the corresponding part, and then connecting Fiber to and to in that order.

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Yokohama, Japan

Osamu Kasuu