CN201017077Y

CN201017077Y - Optical fiber solid closing arrangement module realizing light spot optical fiber tight connecting in optical fiber closing arrangement line array

Info

Publication number: CN201017077Y
Application number: CNU2006201418966U
Authority: CN
Inventors: 侯昌伦; 杨国光
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2006-12-31
Filing date: 2006-12-31
Publication date: 2008-02-06
Anticipated expiration: 2016-12-31

Abstract

The utility model discloses a densely-arrayed optical fiber module, which realizes the dense connection of light spots in a densely-arrayed optical fiber array. The utility model is provided with a base and a press plate. Rectangular, parallel and equally-spaced V-shaped slots are etched at the base. The surfaces of the base and the press plate are plated with thin films. Micro optical fibers are put in the V-shaped slots at the base, and the press plate is put on the micro optical fibers. The base and the press plate are bonded into a whole with the ultraviolet glue. The diameter of the micro optical fibers is 5-25um. The base is made of silicon slices and the press plate is made of glass sheets. The thin film is made from magnesium fluoride and is over 0.3 thick. The beneficial effect of the utility model is as follows: (1) the densely-arrayed optical fiber module realizes the dense connection of light spots in a densely-arrayed optical fiber array; (2) the utility model promotes the imaging precision of a laser typesetting system; (3) the utility model increases the focal depth and reduces the magnification of a focusing lens and the requirement on the position precision at the film exposal.

Description

Optical fiber close packing module for realizing light spot close joint in optical fiber close packing line array

Technical Field

The utility model relates to a realize the closely sealed optic fibre of light spot among the closely arranged array of optic fibre array and closely arrange the module.

Background

In laser scanning equipment such as a laser photocopier, a laser plotter and a direct plate making machine, one main scheme for realizing multi-path light scanning is to adopt a plurality of semiconductor lasers and a multi-path optical fiber close-packed structure to form a light spot line array as an object plane, and then image the object plane on an image plane (film surface) according to a certain proportion through an imaging system, thereby realizing multi-path scanning.

However, since light is distributed in a small central region in a conventional optical fiber, for example, a typical multimode fiber size is 125 μm in outer diameter and 62.5 μm in core diameter (light guide) and only 8 to 10 μm in the case of a single mode fiber. Even if the fibers are arranged without gaps, the spots from the closely packed array are separated (see fig. 6). The light-emitting end face of the optical fiber array is used as an object plane, and light spots obtained on the image plane through an imaging system are also separated, which cannot meet the scanning requirement. If the image plane spot diameter is enlarged by the defocusing method, although the gap between the spots can be filled, the edge quality of the spots is sacrificed.

In order to solve the problem, some optical fibers are closely arranged at a certain angle, and the light spots are closely arranged by controlling the dotting through the delay on a circuit. This method is successful, but the control circuit is complex and cannot solve the problem of short focal depth of the focused light spot.

Disclosure of Invention

The utility model aims at providing a realize the tight optical fiber close packing module of the tight spot of the close packing of optic fibre array.

The device comprises a substrate and a pressing plate, wherein parallel V-shaped grooves with equal intervals are etched on the substrate, films are plated on the surfaces of the substrate and the pressing plate, micro optical fibers are placed on the V-shaped grooves of the substrate, the pressing plate is placed on the micro optical fibers, and the substrate and the pressing plate are integrally bonded through ultraviolet glue.

The diameter of the micro optical fiber is 5-25 micrometers. The substrate adopts a silicon wafer, and the pressing plate adopts a glass sheet. The film is a magnesium fluoride film, and the thickness of the film is more than 0.3 micrometer.

The utility model has the advantages that:

1) The optical fiber close-packed module realizes the light point close-packed connection in the optical fiber close-packed line array;

2) The imaging precision in the laser phototypesetting system is improved;

3) The focal depth is increased, and the requirements on the magnification of a focusing lens and the position precision during film exposure are reduced.

Drawings

FIG. 1 is a schematic structural diagram of a closely-arranged optical fiber module for realizing light spot joint sealing in a closely-arranged optical fiber array;

FIG. 2 is a schematic diagram of the distribution of focused spots when standard optical fibers are used for close packing;

FIG. 3 is a schematic diagram of the distribution of focused spots when micro-fibers are used in close-packing;

FIG. 4 is a schematic diagram of the focal depth of an image surface focused by a lens when micro optical fibers are densely arranged;

FIG. 5 is a schematic diagram of the focal depth of an image plane after focusing by a lens when a standard single mode fiber is adopted;

fig. 6 is a block diagram of the micro optical fiber dense array of the present invention.

Detailed Description

As shown in figure 1, the optical fiber close-packed module for realizing the light spot close connection in the optical fiber close-packed array is provided with a substrate 1 and a pressing plate 2, V-shaped grooves 5 which are parallel and equidistant are etched on the substrate, the surfaces of the substrate and the pressing plate are plated with thin films 6, micro optical fibers 3 are placed on the V-shaped grooves of the substrate, the pressing plate 2 is placed on the micro optical fibers, and the substrate and the pressing plate are bonded into a whole by ultraviolet glue 4. The diameter of the micro optical fiber 3 is 5-25 microns. The substrate 1 is a silicon wafer. The pressing plate 2 is made of a glass sheet. The press plate 2 is a glass plate. The film is magnesium fluoride film, and the thickness of the film is more than 0.3 micron.

The utility model discloses a solve and adopt the tight seal of light spot in the standard optic fibre close packing array on the current laser phototypesetter, moreover because adjacent optic fibre interval is big, need big multiplying power focusing lens and arouse the too short problem that requires too high to the exposure point position of depth of focus, proposed the method that adopts little optic fibre close packing. The micro optical fiber is a thin optical fiber which is drawn under laser heating and has the diameter of about 5-25 microns after a coating layer of a standard single-mode optical fiber is removed. One end of the micro-fiber is connected with the standard single-mode fiber through a transition region, and the standard fiber end is connected with the semiconductor laser through a universal fiber interface. In a standard optical fiber, light is transmitted only in an optical fiber core diameter with a small diameter, and the peripheral part of the core diameter is a cladding with a refractive index lower than that of the core diameter; in the micro-fiber, light is transmitted in the diameter range of the whole micro-fiber, and the air layer around the micro-fiber is the cladding. If the micro-fiber is in direct contact with the fiber or a material with a higher refractive index than the fiber, light energy can be easily coupled into the material with which it is in contact.

In order to prevent the optical energy coupling between the adjacent micro optical fibers arranged, a certain gap d is required to be maintained between the adjacent micro optical fibers arranged. The size of the gap is:

in the formula: λ is the wavelength of light in the optical fiber, n ₁ Is the refractive index of the optical fiber, n ₂ θ is the angle of incidence of light in the fiber, which is the refractive index of air.

In order to arrange the micro optical fibers at equal intervals, the micro optical fibers are arranged on a silicon substrate etched with V-shaped grooves or a magnesium fluoride substrate etched with rectangular grooves, and assuming that the diameter of the micro optical fiber is D, the interval between adjacent micro optical fibers is D, and the interval between adjacent V-shaped grooves is D + D. The silicon wafer etched with the V-shaped groove needs to be plated with a low-refractive index medium film (such as a magnesium fluoride film). The V-shaped groove on the silicon chip is obtained through photoetching and wet etching processes. The upper end of the arrayed micro-fiber array is pressed with a glass sheet coated with a magnesium fluoride film on the surface, and the glass sheet is fixed with a lower substrate through ultraviolet glue (as shown in figure 1). Since the diameter of the micro-fiber is very small, in order to prevent the micro-fiber from breaking, the substrate and the standard fiber near the transition region are fixed to the base by ultraviolet glue (as shown in fig. 6) to form a whole.

If standard optical fibers are closely arranged by a conventional method, the center distance between adjacent optical fibers is 125 microns, and if the resolution requirement of the film is 2540dpi, the magnification of an imaging lens required for imaging the closely-arranged optical fiber light spot array on the film is 12.5 times. The larger the lens magnification, the shorter the focal depth; it is difficult to use if the position of the film is highly required by using an imaging lens of 12.5 times (as shown in fig. 5). If the micro optical fibers with the diameter of 20 micrometers are densely arranged, the interval between the adjacent micro optical fibers is micro 4 micrometers, the center distance between the adjacent micro optical fibers is 24 micrometers, and if the resolution requirement of the film is 2540dpi, the multiplying power from the end face of the densely arranged micro optical fiber array to the imaging lens of the film is 2.4 times, the multiplying power of the lens is greatly reduced, the focal depth is greatly increased (as shown in figure 4), and the requirement on the position precision from the focusing lens to the film is greatly reduced.

Examples

1) Stripping the coating layer from the single-mode optical fiber;

2) Converging high-power laser on the optical fiber through a focusing mirror, melting the optical fiber by heat generated by the laser, and stretching the optical fiber to obtain a micro optical fiber with the diameter of 20 microns;

3) Etching V-shaped grooves with the spacing of 24 microns in parallel on a silicon chip, and plating a magnesium fluoride film with the thickness of 0.3-1 micron on the surface of the silicon chip etched with the V-shaped grooves; arranging the ends of the micro optical fibers in a V-shaped groove on a silicon chip in parallel and horizontally, covering a glass sheet with a film of 0.3-1 micron plated on the surface on the micro optical fiber array, and fixing the glass sheet and the silicon chip by ultraviolet glue, as shown in figure 1;

4) Fixing the silicon chip and the standard optical fiber near the transition region with ultraviolet glue and the base, and connecting the end of the standard optical fiber with an FC interface (as shown in FIG. 6) connected with the semiconductor laser;

5) And 2) adjusting the distance between the laser convergence point and the heated optical fiber to obtain micro optical fibers with different diameters.

Claims

1. The optical fiber close-packed module for realizing light spot close connection in the optical fiber close-packed array is characterized by comprising a substrate (1) and a pressing plate (2), wherein parallel V-shaped grooves (5) with equal intervals are etched on the substrate, the surfaces of the substrate and the pressing plate are plated with films (6), micro optical fibers (3) are placed on the V-shaped grooves of the substrate, the pressing plate (2) is placed on the micro optical fibers, and the substrate and the pressing plate are bonded into a whole by ultraviolet glue (4).

2. The module of claim 1, wherein the diameter of the micro-fibers (3) is 5-25 μm.

3. The optical fiber close-packed module for realizing the optical fiber close-packed line array according to claim 1, characterized in that the substrate (1) is made of silicon wafer.

4. An optical fiber dense-packing module for realizing dense-packing optical fiber arrays according to claim 1, characterized in that the pressing plate (2) is made of a glass plate.

5. The module of claim 1, wherein the thin film is a magnesium fluoride thin film having a thickness greater than 0.3 μm.