JPS5820746A - Preparation of optical fiber for supporting single circular polarized light - Google Patents

Abstract

PURPOSE:To prepare the titled fiber with immobilizing double refraction based on a circular polarized light mode in the fiber, by drawing a parent material for optical fiber at a constant speed, covering it with a coating material while twisting it. CONSTITUTION:The parent material 1 for optical fiber 1 is supporting by the chuck 2, inserted into the electric furnace 3 gradually, and spun into the optical fiber 5 while being melted under heating by the heater 10. The fiber is sandwiched by the rotary rollers 31 and 32, and sent out forcedly. The sent fiber 5 is rotated in the arrow direction 35 and wound by the winder 34 in the arrow direction 36. Thus, the fiber 5 is twisted during its travel between the rollers 31 and 32 and the winder 34. The twisted fiber 5 is covered with a primer coat by the primer coating device 6 and the electric furnace 7, covered with a coating material by the over coating device 8 and the electric furnace 9 and baked. Urethane, silicone, nylon, etc. is used as the coating material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an fmK'R radius for covering the coating material when drawing the base material at a constant speed.
The present invention relates to a method of manufacturing an optical fiber for maintaining single-circular polarization, characterized in that the birefringence for the circularly polarized light mode caused by the twist is fixed within seven eyes by covering with a coating material.

Conventionally, as a manufacturing method for a single mode optical fiber that maintains a single polarized wave, the base material 0/wo for optical 7 eyelids and the base material 0/o are parallel to the axis as shown in the figure. A method for manufacturing an optical fiber that mechanically polishes a double-sided OS, O2, covers it with a glass tube different from the base material, and then draws a line using a drawing device to give an elliptical shape or stress birefringence, and After placing the core/cladding base material/l and the stress applying rod/J and/Jt-jacket tube/g as shown in Fig.

There have been methods for producing optical 7-aipa O by drawing a line using a drawing device to give a stress-birefringent or elliptical core/cladding. In order to eliminate this drawback, the present invention aims to eliminate these drawbacks. 1. When drawing a normal single mode fiber base material, By twisting the fiber before applying the coating material, and fixing the stress generated by the torsion within the fiber, the axial symmetry of the refractive index distribution within the fiber is fixed. The aim is to obtain a Phi-no (7-eye) that has lost its properties and has improved retention of the circularly polarized light mode.

OIJ/f, 3 will be described in detail below with reference to the drawings.
The figure shows an embodiment of the present invention, in which a base material for an optical fiber 7 is supported by a chuck, gradually inserted into an electric furnace 3, and heated and melted by a heater 10 to form an optical fiber.
The optical fiber j is then spun between rotating rolls 3/ and 3-2, and is forcibly sent out using an angular rotating roll.
The optical fiber sent out is arrow 3! A roll mll that can be wound in the direction of arrow 34 while rotating in the direction of
In this way, twisting can be seen between the rolls 3/3λ and the winding machine J4t. This twisted light 7 eyeper is subjected to a primary coat using a primary coater, and then baked in an electric oven for primary coat drying.
Bake and tighten using an electric oven for overcoat drying◎
Use silicone or nylon as the coating material. By carrying out such a process, the stress line due to the twist occurring in the optical fiber is fixed in the fiber ◎Specifically, D-2 rotations per /m~? 0 rotation is given to fix the birefringence due to stress in the optical 7 eyeper. In this way,
The birefringence for the circularly polarized light mode is enhanced, the beat length for the circularly polarized light mode can be set to about /f~de00, and a single-circularly polarized light-maintaining optical fiber that can hold a single circularly polarized light can be manufactured.

As explained above, when the optical fiber base material of the present invention is drawn at a constant speed, the optical fiber is twisted before being covered with the coating material, and the stress generated by the twisting is caused by covering the optical fiber with the coating material. The manufacturing method for single-circular polarization-maintaining optical fiber, which has improved birefringence for the circularly polarized mode by fixing it within the fiber, uses the same base material and fiber culm as for ordinary single mode fibers. Therefore, the transmission loss at the wavelength/,jμ shoulder is set to 0. JdB/k
Since the vAD base material can be lowered to m and can be manufactured continuously, it is better to use vAD base material than K! θKm
It is also possible to make the YrM longer.
By using a plate, it is possible to intelligently convert the light to linearly polarized light immediately after the fiber exits, and in long-distance optical transmission systems and submarine optical cable transmission systems, it is possible to de-determine the coupling efficiency in repeating systems consisting of optical fibers mainly having a slab structure such as optical amplifiers. It is effective in increasing the above-mentioned level and suppressing the fluctuation to below ±o,i@.1 Also, in order to diversify the functions of optical components in subscriber systems and intra-office optical transmission systems, slab optical guides are effective. Although it is essential to use a wave path, the single-circular polarization-maintaining optical 7-eyeper of the present invention has the advantage that it can be used as an important fiber that enables stable coupling in combination with a λβ plate. .

[Brief explanation of drawings]

Fig. 1 is a diagram showing the base material in the conventional manufacturing method and the shape of the base material after polishing, Fig. 1 is an inserted view of the base material and stress imparting rod in the conventional manufacturing method, and Fig. 3 is a diagram showing the shape of the base material after polishing. This is a diagram illustrating an example of the manufacturing method. J
...Stress applying base material, /4t-jacket pipe, /...
・Base material for optical fiber, co-chuck%3-electric furnace,
Da-capstan! ...Hikari 7 Aipa,' 4 ・
・・Primary coater, ri・・Electric furnace for drying primary coat.

Claims (1)

[Claims] 1. A rod-shaped optical core fiber is gradually inserted into the furnace from one end of the furnace and spun to the required diameter while being heated and melted, and the spun optical fiber is pulled out from the other end of the furnace at a constant speed. In drawing the optical core, the fiber M before the primary coating is forcibly fed out with rollers applying pressure from both sides, and the core is twisted before being wound by a winding machine. A single circularly polarized light is maintained by coating the 7-eye/(with a coating material such as urethane, silicone, or nylon) to fix the birefringence of circularly polarized light caused by twisting within the fiber. Method 0 of manufacturing an optical fiber for single-circularly polarized light, characterized by the following: