RU2235072C2 - Method for making fibre-optic member and microchannel structure - Google Patents

Abstract

FIELD: optical and electronic industry.

SUBSTANCE: invention relates to members of fibre-optic and microchannel enhancers. Invention can be used in making flexible and rigid supermode and multimode light guides and transducers, sintered fiber-optic plates, fiber-optic inverters (turning devices), focons and microchannel plates. Method for making fiber-optic members and microchannel structures will allow to simplify the process for preparing fiber with complex pattern of core and shell, provides reducing consumption of materials and diminishing labor intensity. Method involves drawing single light guides, re-drawing single-core light guides to multi-core and supermulti-core ones, sintering and pressing multi-core light guides to blocks and their mechanical finishing. From small bars of round or right-angled form prepared of glass or polymers for core and for fiber shell rods are drawn separately of similar or inter-confirming section 0.4-6 mm. Then packet is collected from rods showing round or polyhedral, for example, hexahedral section form, internal structure is formed in stacking the future single fiber by form and ratio of core and shell sizes. Then a single elementary fiber of size from 5 mcm to 5 mm is drawn from the selected packet. In drawing for the best melting rods made of glass core and shell a packet is evacuated, a single fiber with one or some monolith light-guiding cores enclosed by one or some shells is formed that are used for assembly the second packet for drawing multi-core fiber followed by pressing blocks used for making fiber-optic or microchannel plates.

EFFECT: improved making method.

7 cl, 8 dwg, 3 ex

Description

The invention relates to the optical and electronic industries, in particular to elements of fiber optics and microchannel amplifiers. The invention can be used in the manufacture of flexible and rigid single-mode and multimode optical fibers and converters, sintered fiber optic plates (FOP), fiber-optic inverters (turn signals), focons and microchannel plates (MCPs) and other fiber-optic elements and microchannel structures, containing a light guide core, one or more shells made of glass or polymers.

Fiber optic elements: flexible and rigid single-mode and multimode optical fibers and bundles, converters, sintered fiber optic plates, fiber-optic inverters (turn signals), tapers and microchannel plates, and other fiber-optic products consist of a single fiber or group in parallel regularly stacked single fibers consisting of a core made of glass or polymer with a single refractive index, and a shell made of glass or polymer with a refractive index less than the core. Many HEIs use additional shielded sheaths from stained glass or soluble glass sheaths, which are removed during the manufacturing process, for example, flexible fiber bundles by pickling. Microchannel plates are formed from bilayer fibers in which the core is made of soluble glass.

Known methods for manufacturing a single fiber are either pulling fibers from double or triple crucibles through dies directly from molten glass, or the most common method for manufacturing optical fibers and MCPs is the “tube-tube”, which involves pulling single fibers from a kit made up of a tube or several tubes inserted one into the other, into the last (inner) of which a staff is inserted.

A known method of manufacturing fiber from spinnerets see, for example, US patents No. 4193782, C 03 B, 37/02, 03.18.1980; No. 4217123, С 03 В, 37/02, 08 12.1980

The disadvantage of these methods is the fact that the stretching of the fiber must be carried out in the high-temperature range of viscosities, in which there is an increased interdiffusion of the glass of the core and the sheath, which significantly impairs the optical fiber properties of the fiber. In addition, crucibles and a die should be made of an expensive material - platinum.

Closest to the technical nature of the proposed method is a method of manufacturing a single fiber from a set of "staff-tube", which can be considered classic in the production technology of optical fiber and MCP, see US patent No. 5.015.909, Int. C1. C 03 C, 3/108, U.S. C1. - 313/103 R. 05/14/1991

According to the known method, a single fiber is made as follows: first, a tube and a head are made, the head is inserted into the finished tube and the set thus obtained is heated to soften in an oven and a single two-layer fiber is pulled. Single fibers are drawn into a bundle, reheated, and the multicore fiber is pulled, which is sintered into a block.

With all its advantages, this method has a number of significant drawbacks that limit its use. Firstly, the complexity of manufacturing high-precision tubes for the shell, which in many cases have to be made mechanically by drilling a hole in the head, which is an inefficient and expensive operation that requires special equipment. The manufacture of tubes directly from molten glass also requires large-sized machines and powerful melting units. Secondly, the complexity or, in some cases, the impossibility of manufacturing racks and tubes of a special profile, which must be given to the primary fiber. Thirdly, the need to have large-sized workpieces of racks and tubes.

The objective of the present invention is to simplify the manufacture of fibers with a complex profile of the shell and core, increase efficiency - reducing the cost of materials and labor, universalizing the process and expanding the scope of the method for all types of fiber and microchannel structures.

The problem is solved due to the fact that in the method of manufacturing fiber optic elements and microchannel plates of glass and polymers, which involves pulling single fibers, pulling single-core fibers into multi-core and multi-core, sintering and pressing multi-core fibers into blocks and their mechanical cutting, from round or rectangular beams made of glass for the core and for the fiber sheaths are separately pulled by rods of the same or mutually consistent cross section of 0.4-6 mm. Then, a packet having a round or multifaceted, for example, hexagonal cross-sectional shape is assembled from the rods, when laying, the internal structure of the future single fiber is formed in the shape and size ratios of the core and shells. Then, an elementary single fiber from 5 μm to 5 mm in size is pulled from the stacked bag, and when pulled to better fuse the glass rods of the core and the shells, the bag is evacuated, thereby forming a single fiber with one or more monolithic light-guiding cores surrounded by one or more shells. The elementary fibers obtained in this “tubeless” way are either finished products or are further processed according to known technological schemes. A single fiber is used to assemble a second bag for drawing multi-strand fiber (MFL). And if it is required to obtain elements with a higher resolution, a packet for drawing super-multi-core optical fibers (SMGS) is reassembled from the MSS. Stranded or super-stranded fiber is cut into pieces of size 40-100 mm, laid in a mold and pressed into a block. The block is cut into plates from which either fiber optic elements or blanks of microchannel plates are made. The original glass rods can also be drawn from molten glass by spinneret method and packed into a bag in a bag having a square cross-sectional shape or a polygonal cross-sectional shape.

Moreover, a single fiber may have several light guide cores with a cross-sectional shape different from the cross-sectional shape of a single fiber, for example polygonal with a round shape of a single fiber or square with a hexagonal shape of a single fiber.

When the bag is pulled out for better sintering of the rods and to prevent the formation of bubbles at the boundaries of sintering of the rods, a vacuum of at least 0.4 atm is created in it.

A significant difference and advantage of the proposed method is that for the implementation of the formation of an elementary light guide fiber does not require the manufacture of precision tubes and a massive staff for the core. Another advantage of the method is that it is possible to form any profile of the core and shells both in size and in configuration, which, when applied to vacuum, form a continuous optical medium, figuratively speaking, the method allows you to draw the structure of an elementary fiber as a mosaic picture. Increases profitability, because you can make a fiber element from a small amount of material, there is no glass loss, as in the manufacture of tubes, when more than half of the glass of the drilled inside of the workpiece is lost. Significantly reduces the complexity, because completely eliminates the energy-intensive process of manufacturing tubes. The great advantage of the method is its versatility, it is applicable for the manufacture of almost all types of fiber elements and microchannel structures.

The invention is illustrated by drawings, which include the following data.

Figure 1 shows the scheme for obtaining the initial single rods from the glasses of the core and shells, where 1-4 are the initial blanks from the glasses of the core and shells, 5 is a direct heating furnace, 6 is a pulling mechanism, 7 is the initial rod.

Figure 2 shows a cross section of a block laid from round rods in a hexagonal packet, where 8 is the core, 9 is a transparent shell.

Figure 3 shows a cross-section of a block laid from rods of a hexagonal cross section in a packet of a hexagonal cross section, where 8 is a core, 9 is a transparent shell, 10 is a colored absorbent shell.

Figure 4 shows the scheme of dragging packets into a single fiber or into a multicore fiber, where 11 is a packet, 5 a direct heating furnace, 12 is a vacuum pump, 6 is a pulling mechanism, 7 is a finished single-core or multi-core fiber.

Figure 5-a shows a cross section of an elementary single fiber with one sheath, and figure 5-b with two sheaths, where 8 is the fiber core, 9 is a transparent sheath, 10 is a colored absorbent sheath.

Figure 6-a shows a cross section of a single unitary fiber with one square — and FIG. 6-b) —with two rectangular light-guiding cores, where 8 are cores, 9 is a transparent sheath, 10 is an absorbent sheath.

Example 1. To obtain the original single fiber for the manufacture of a flexible multimode fiber according to figure 1, the round glass beads of the core core 1 with a refractive index of 1.6, and the shell 2, with a refractive index of 1.48, are placed in the furnace 5, heated to a glass drawing temperature of 800 ° C and pulled using a machine 6, drills 7 with a diameter of 0.6 mm. The drills 7 are laid in FIG. 2 in a hexagonal sectional bag with an apopheme size of 30 mm; moreover, the core 8 is laid out from the glass core and the shell 9 is made from the glass of the shell. According to FIG. 4, the bag 11 is placed in the furnace 5 and heated a second time to a softening point of 800 C and pulled using a machine 6 a single elementary fiber 7 with a size of 0.6 mm When pulling the package 11 to better sinter the rods and prevent the formation of bubbles, vacuum using a vacuum pump 12. A cross section of an elementary fiber is shown in Fig.5-a. The light guide has a core 8 surrounded by a single sheath 9 of transparent glass. From the elementary fiber obtained in this way, a flexible bundle is assembled according to the accepted technology — vibro-laying.

Example 2. To obtain the original single fiber for the manufacture of the fiber optic plate according to Fig. 1, round posts made of glass from the core of TBF 10-1, with a refractive index of 1.81 of a transparent sheath BO50 2, with a refractive index of 1.48 and a dark-shielded sheath WTO73M 4 are placed in furnace 5, heated to a glass softening temperature, respectively, to 730 °, 790 °, 795 ° and pulled using a machine 6, drills 7 with a diameter of 0.6 mm. The dartboard 7 according to FIG. 3 is placed in a hexagonal cross-sectional bag with an apopheme size of 30 mm, with the core 8 being laid out from the glass core, the casing 9 from the transparent glass and the casing 10 from the absorbing glass. FIG. 4, the bag 11 is placed in the furnace 5, they are heated a second time to a softening temperature of 795 ° and a single elementary optical fiber 7 of 0.6 mm in size is pulled using a machine 6. When pulling the bag 11 for better sintering and to prevent the formation of bubbles, vacuum using a vacuum pump 12. A cross section of a single elementary fiber is shown in Fig.5-a. The light guide has a core 8 surrounded by a first sheath 9 of transparent glass and a second sheath 10 of shielding glass. A single fiber is used to assemble a second packet according to accepted technology for drawing multicore fibers (MF). And if it is required to obtain elements with a higher resolution, a packet for drawing super-multi-core optical fibers (SMGS) is reassembled from the MSS. Stranded or super-stranded fiber is cut into pieces of size 40-100 mm, laid in a mold and pressed into a block. The block is cut into plates from which fiber optic plates are made.

Example 3. To obtain the original single fiber for the manufacture of microchannel plates in figure 1, round posts made of soluble glass core МКС3 3, and active glass МКО404 4, which has secondary electron emission upon reduction in hydrogen, are placed in the furnace 5, heated to softening temperature glass 795 ° C for ISS 3 and 712 ° C for MKO404 and pulled using machine 6, drills 7 with a diameter of 0.6 mm. The drills 7 are laid in FIG. 2 in a hexagonal bag with an apopheme size of 30 mm, with the core 8 being laid out from the glass of the soluble core and the shell 9 made of active glass. According to FIG. 4, the bag 11 is placed in the furnace 5 and heated a second time to a temperature of 795 ° C and pulled using a machine 6 a single elementary fiber 7 with a size of 0.8 mm When pulling the bag 11 for better sintering and to prevent the formation of bubbles, vacuum using a vacuum pump 12. A cross section of a single elementary fiber is shown in Fig.5-a. The fiber has a soluble core 8 surrounded by an active glass sheath 9. A single fiber is used to assemble a second packet according to accepted technology for drawing multicore fibers (MF). Stranded or super-stranded fiber is cut into pieces of size 40-100 mm, laid in a mold and pressed into a block. The block is cut into plates, from which the blanks for microchannel plates are made.

The examples shown in figures 1-6 clearly demonstrate that the use of the proposed method for the manufacture of fiber-optic elements and microchannel structures simplifies the manufacture of optical fibers with a complex profile of the cladding and core. Increases profitability - reduces waste materials and reduces labor intensity, because according to the known method, OZHS are made of high-precision polished tubes and racks, which are made by machining. There is a universalization of the process and the expansion of the scope of the method for all types of fiber and microchannel structures. For example, to make a fiber with two square cores in Fig.6-b), using the traditional method of the "tube-tube" in principle is possible, but not economically feasible, because it would be necessary to produce a square tube and square racks for the core and triangular for the dark shell, which would require special equipment and large labor costs.

The process for polymers is identical across all operations. The only difference is that they use drawing temperatures according to the softening temperatures of the polymers.

Claims (7)

1. A method of manufacturing fiber optic elements and microchannel structures, including pulling single fibers, pulling single-core fibers into multi-core and super-multi-core, sintering and pressing multi-core optical fibers into blocks and their mechanical cutting, characterized in that from round or rectangular frames made of glasses or polymers for the core and for the fiber sheaths, separately pull rods of the same or mutually consistent different cross-section of 0.4-6 mm, then from the rods a packet having a round or multifaceted, for example, hexagonal cross-sectional shape is removed, the internal structure of the future single fiber is formed when laying according to the shape and size ratios of the core and shells, then an elementary single fiber of 5 microns to 5 mm in size is pulled from the stacked packet; stretching for better fusion of the core rods and glass rods, the package is evacuated, a single fiber is formed with one or more monolithic light-guiding light cores surrounded by one or more their shells, which are used to assemble the second package for drawing multicore fibers, from which blocks are pressed for the manufacture of fiber optic or microchannel plates. 2. The method according to p. 1, characterized in that the source rods are pulled from the molten glass by a spinneret method. 3. The method according to p. 1, characterized in that the source rods are placed in a package having a square cross-sectional shape. 4. The method according to p. 1, characterized in that the source rods are placed in a package having a polygonal cross-sectional shape. 5. The method according to p. 1, characterized in that the single fiber has several light guide cores. 6. The method according to p. 1, characterized in that the single fiber has a core with a cross-sectional shape different from the cross-sectional shape of a single fiber, for example polygonal. 7. The method according to p. 1, characterized in that when pulling the package in it create a vacuum of at least 0.4 atm.

Images