Alcatel N.v.

International Standard Electric Corporation

Standard Elektrik Lorenz Ag

Rolf Rossberg

Rolf Heidemann

Thomas Pfeiffer

Henning Bulow

Jurgen Otterbach

Rainer Fritschi

Peter Schmid

A coupler (1) made of optical fibers is provided with a device for detecting the light that is carried in one of the fibers at the coupler output in operation. For that purpose, the coupler (1) embedded in an enclosure (2) has at the coupler output a lens body (8) enclosing the optical fiber (pigtail 6) and a detector (9) aimed at the lens body (8). With the detector, during coupler operation, lost light dissipated via the primary coating of the optical fiber is received by the lens body (8 ) and carried by the detector (9) to an electrical evaluator.

Optical coupler and amplifier

To make a fused fiber coupler (1) which is especially suited as a pump coupler for use in fiber amplifiers, exhibits low sensitivity to polarization, and can be spliced in with low loss, commercially available single-mode fibers are employed. After completion of an elongating process and interruption of heat from a heat supply, the input-fiber pair (fiber ends 4, 5) and the output-fiber (fiber ends 6, 7) of two fused lengths of the fiber (2, 3) are twisted by 180.degree. about their common axis and fixed in this position.

Method of manufacturing a fused fiber coupler

To increase the pump efficiency in a fiber-optic amplifier, the pump coupler (2) is fabricated from a fiber whose mode field diameter for the pump light is adapted to the mode field diameter of the active length of fiber (7). In an alternative solution, the arm of the pump coupler (2) coupled to the pump source (1) on the one hand and connected to the active length of fiber (7) on the other hand consists of a fiber adapted to the mode field diameter of the active length of fiber (7), and the arm of the pump coupler (2) serving as a connection to the incoming transmission line (8) consists of a fiber corresponding to the optical waveguide of the transmission line (8).

Fiber optic amplifier

During the process of manufacturing polarization-selective fused-fiber couplers (1) having two or more input fibers and two or more output fibers and formed in the coupling region (fused region 6) from parallel, nonbirefringent, matched-cladding single-mode fibers, prior to the fusion of the fibers, linearly polarized light with a selected wavelength is fed into one of the input fibers (2) and detected at the ends of the two output fibers (3). The fibers are thereupon fused together with the coupler (1) being drawn until the coupling between the two fibers ceases to fluctuate. The source of heat is then turned off. With the method it is possible to manufacture fused-fiber couplers (1) whose lengths are only approximately 10 mm to 15 mm.

Method of manufacturing an optical fused-fiber coupler and the coupler

A method is disclosed in which the bare glass fibers are firmly soldered into a solder bath of the splicing device and, after being scored and broken, unsoldered again. To that end, the glass fibers are placed across the solder bath, the solder is heated, and the level of the molten solder is raised above the glass fibers by pressing a slide into the solder trough. The heat supply to the solder bath is subsequently cut off. After the solder has cooled, the glass fibers are firmly fixed therein. To release the fixed glass fibers, the solder is liquefied again. The device for carrying out the method consists essentially of a slotted guide bar, which serves to hold the glass fibers apart, and the solder bath. The latter is a copper block which is thermally insulated from the splicing device and has a projection at one end for attaching a soldering iron.

Method and device for releasably fixing bare glass fibers in a splicing

To avoid having to metallize a bare glass fiber prior to soldering it into a hole of a metal part to obtain a hermetically sealed lead-through bushing, the solder is permitted to shrink onto the glass fiber. This is achieved by either soldering an additional solder body to the metal part outside the hole or providing the wall of the hole with a nonsolderable coating over part of its length. If the metal part is designed as a sleeve, a recess exposing part of the hole causes the solder to firmly shrink on to the bare glass fiber during solidification. The hermetic seal is obtained by arranging the connections of the solder with the metal part and with the glass fiber essentially one behind the other in the longitudinal direction of the glass fiber.

Hermetically sealed glass fiber bushing

The spatial position of the core of an optical waveguide (1) can be observed exactly in that the optical waveguide is irradiated, in two mutually perpendicular directions, with parallel light, which thereafter passes through each time one rod lens (31, 32) and into a deflecting optical system (8, 9, 10). With the aid of this deflecting optical system it is possible to produce two side-by-side images of the optical waveguide and its core. With the aid of such an arrangement the cores of two optical waveguides to be joined, can be optically aligned with respect to each other in a simple way.

Arrangement for visualizing the cores of optical waveguides

In the device the base and the swivel members consist of three spaced plates disposed one above the other. That is, a baseplate (1), an intermediate plate (3) and a supporting plate (5). The baseplate (1) is connected to the intermediate plate (3) disposed above it, via a first hinge (2) provided for within the area of one longitudinal side, and this intermediate plate (3), in turn, and within the area of the longitudinal side lying opposite the first hinge (2), is connected to the supporting plate (5) disposed thereabove, via a second hinge (4). Both the intermediate plate (3) and the supporting plate (5) are jointly capable of being swivelled about the swivel axis of the first hinge (2) and the supporting plate alone is capable of being swivelled about the swivel axis of the second hinge (4). The supporting plate (5) contains the object receptacle (8) whose center line is in agreement with the axis of the object. The positions of this center line and of the swivel axes are disposed in the corner points of a right-angled triangle, with the spacing between the swivel axes forming the hypothenuse of the triangle. The swivel axes of the hinges (2, 4) and the center line of the object receptacle (8) are staggered in relation to one another in both the horizontal and the vertical direction.

Growing community of inventors

Schwieberdingen, Germany

Rolf Rossberg