CN1936634A - Method for realizing optical point joint seal in optical-fiber close-packed array - Google Patents

Abstract

The invention discloses a method of the spot joint seal in the optical fiber close-spaced linear array. The process is: 1) one end of the standard single mode optical fiber is draw to the micro optical fiber with diameter of 5-25 mum which includes the standard optical fiber and the transition region; 2) Many micro optical fiber which the end is interval and parallel are lain on the silicon base plate coated the magnesium fluoride on the surface with the V groove or the magnesium fluoride base plate with the rectangle groove; 3) the glass sheet coated the magnesium fluoride on the surface or the magnesium fluoride board is set on the micro optical fiber to form the micro optical fiber close-spaced array fixed with the base plate by the ultraviolet glue; 4) the end of the standard optical fiber is connected with the semiconductor laser by the FC interface and the close-spaced micro optical fiber array outputs the spot array. So the invention can improve the imaging precision of the laser phototypesetting system and the focal depth but decrease the demand of the position precision when the film exposures.

Description

Realize the method that luminous point connects airtight in the optical fiber solid matter linear array

Technical field

The present invention relates to provide the technology of the optical fiber solid matter linear array in the laser photocomposing system, relate in particular to a kind of method that realizes that luminous point connects airtight in the optical fiber solid matter linear array.

Background technology

In laser photocomposing machine, laser drawing machine and direct this class laser scanning equipment of laminator, a major programme that realizes multipath light scanning is to adopt a plurality of semiconductor lasers, spot line array of multi-channel optical fibre solid matter structure as object plane, be imaged on by a certain percentage on the picture plane (film surface) through imaging system then, thereby realize multi-channel scanning.

Yet because the ordinary optic fibre structure, light only distributes in very little zone, center in the optical fiber, and for example a typical multimode optical fiber size is 125 microns of external diameters, and core diameter (light guide) is 62.5 microns, if the single-mode fiber core diameter has only 8～10 microns.Not arranging even optical fiber has the gap, also is (referring to the Fig. 6) that separates between the luminous point that close-packed array sends.As object plane, through imaging system, the luminous point that obtains on as the plane also separates with the fiber array light output end, and this can not satisfy the scanning requirement.If adopt the method for out of focus to enlarge the image planes spot diameter, though can cover and luminous point between the gap, can sacrifice the edge quality of luminous point.

In order to address this problem, the employing that has is optical fiber solid matter inclination certain angle, controls by the time-delay on the circuit and gets ready, makes the luminous point solid matter.This method is successful, but the control circuit complexity can not solve the short problem of focal spot depth of focus.

Summary of the invention

The objective of the invention is to propose a kind of method that realizes that luminous point connects airtight in the optical fiber solid matter linear array in order to solve problems of the prior art.

It comprises the steps:

1) end of standard single-mode fiber being drawn out diameter is 5～25 microns low-light fibre, and it comprises standard fiber, zone of transition and low-light fibre;

2) the fine end part interval horizontal parallel of above-mentioned many low-lights is arranged in the surface and is coated with the silicon chip that has V-shaped groove of magnesium fluoride film or has on the magnesium fluoride substrate of rectangular channel, arrangement pitch is that the fine diameter of low-light adds the fine spacing d of adjacent low-light, wherein, $d\≥\frac{\mathrm{\λ}}{{\mathrm{\π}\·n}_1\sqrt{{\sin }^2{\mathrm{\θ}-(n_2/n_1)}^2}}$ In the formula: λ is that light is at optical fiber medium wavelength, n ₁Be optical fibre refractivity, n ₂Be air refraction, θ is the incident angle of light in optical fiber;

3) above the low-light fibre on the substrate, be provided with glass sheet or the magnesium fluoride thin plate that the surface is coated with magnesium fluoride film, and fix, form the fine close-packed array of low-light by ultraviolet glue and substrate;

4) the standard fiber end is connected with semiconductor laser by the FC interface, the low-light fibre array end output array of light spots of solid matter.

Beneficial effect of the present invention:

1) realized that the luminous point that multi-channel optical fibre is closely packed on the horizontal line connects airtight arrangement;

2) improved the precision of imaging in the laser photocomposing system;

3) increased depth of focus, the requirement of the positional precision when reducing to exposure.

Description of drawings

Fig. 1 is the fine solid matter synoptic diagram of low-light of the present invention;

Fig. 2 is a standard single-mode fiber synoptic diagram of removing 125 micron diameters of coat;

Fig. 3 is a single-mode fiber that utilize to remove coat, and the diameter range that processes by the high temperature drawing process is at the fine synoptic diagram of 5～25 microns low-light;

Fig. 4 is that low-light fibre of the present invention is closely packed in synoptic diagram on the silicon substrate that has V-shaped groove;

Fig. 5 is that low-light fibre of the present invention is closely packed in synoptic diagram on the magnesium fluoride substrate that has rectangular channel;

Fig. 6 is the distribution schematic diagram of focal spot when adopting the standard fiber solid matter;

Fig. 7 is the distribution schematic diagram of focal spot when adopting low-light fibre solid matter;

Fig. 8 is through image planes depth of focus synoptic diagram after the lens focus when adopting low-light fibre solid matter;

Image planes depth of focus synoptic diagram after camera lens lens focus when Fig. 9 is the employing standard single-mode fiber;

Figure 10 is the fine close-packed array module map of low-light of the present invention.

Embodiment

Adopt on the existing laser photocomposing machine in order to solve that luminous point can not connect airtight in the standard fiber close-packed array, and because the adjacent fiber spacing is big, need big multiplying power condenser lens and cause that depth of focus is too short to the too high problem of exposure station status requirement, proposed to adopt the method for the fine solid matter of low-light.The low-light fibre is after standard single-mode fiber is removed coat, to draw out the thin optic fibre (as shown in Figure 3) of diameter about 5～25 microns that comes under LASER HEATING.One end of low-light fibre links to each other with standard single-mode fiber by a zone of transition, and the standard fiber end is connected with semiconductor laser by general optical fiber interface.In standard fiber, light only transmits in the very little optical fiber core diameter of diameter, and the core diameter periphery is the low covering of refractive index ratio core diameter; And in the low-light fibre, light transmits in the fine diameter range of whole low-light, and the fine surrounding air layer of low-light is covering.Directly contact if low-light is fine, go in the material that luminous energy can be easy to be coupled to it contacts with optical fiber or the material higher than optical fibre refractivity.One of key issue of this invention is the covering problem when solving low-light fibre solid matter.

In order to produce the luminous energy coupling between the adjacent low-light fibre that prevents to arrange, need keep certain clearance d (as shown in Figure 1) when arranging between the adjacent low-light fibre.The size in gap is:

$d\≥\frac{\mathrm{\λ}}{{\mathrm{\π}\·n}_1\sqrt{{\sin }^2\mathrm{\θ}-{(n_2/n_1)}^2}}$

In the formula: λ is that light is at optical fiber medium wavelength, n ₁Be optical fibre refractivity, n ₂Be air refraction, θ is the incident angle of light in optical fiber.

Low-light is fine equidistantly to be arranged in order to allow, and the low-light fibre is arranged on the magnesium fluoride substrate of the silicon chip that is etched with V-shaped groove or rectangular channel, and the diameter of supposing the low-light fibre is D, adjacent low-light fibre be spaced apart d, the spacing of adjacent V-shaped groove or rectangular channel is D+d.If adopt the silicon chip that is etched with V-shaped groove, then need to plate one deck low refractive index dielectric film (as magnesium fluoride film) on the silicon chip.V-shaped groove on the silicon chip obtains by photoetching, wet-etching technology; Rectangular channel processes by photoetching, beam-plasma etching.Arrange good low-light fibre array upper end and press lastblock magnesium fluoride thin slice or surface to be coated with the glass sheet of magnesium fluoride film, magnesium fluoride thin slice or glass sheet are fixed (as Fig. 4, shown in Figure 5) by ultraviolet glue and following substrate.Because the fine diameter of low-light is very thin, in order to prevent the fine fracture of low-light, substrate and standard fiber be fixed (as shown in figure 10) near the zone of transition part by ultraviolet glue and base, form one.

If adopt conventional method closely to arrange with standard fiber, adjacent fiber centre distance is 125 microns, if the resolution requirement of film is 2540dpi, then to be imaged onto the multiplying power of the imaging len that needs on the film be 12.5 times to solid matter optical fiber array of light spots.The lens multiplying power is big more, and depth of focus is just short more; If use 12.5 times imaging len very high to the status requirement of film, practical difficulty (as shown in Figure 9).If the employing diameter is the fine solid matter of 20 microns low-light, fine little 4 microns at interval of adjacent low-light, the fine centre distance of adjacent low-light is 24 microns, if the resolution requirement of film is 2540dpi, then the multiplying power from solid matter low-light fibre array end face to the imaging len of film is 2.4 times, the multiplying power of lens is dwindled greatly, and depth of focus increases (as shown in Figure 8) greatly, and the requirement to the positional precision of film reduces greatly to condenser lens.

Embodiment 1

1) single-mode fiber is peelled off coated layer;

2) powerful laser is converged on the optical fiber by focus lamp, the heat that laser produces is melted optical fiber, and getting diameter by stretching optical fiber is 20 microns low-light fibre;

3) the parallel spacing that etches is 24 microns a V-shaped groove on silicon chip, and the face that is etched with V-shaped groove on silicon chip plates a layer thickness at 0.3～1 micron magnesium fluoride film; The low-light fibre is held level with both hands in the horizontal V-shaped groove on silicon chip of row, be coated with the glass sheet of 0.3～1 micron film then at low-light fibre array upper cover upper surface, fix by ultraviolet glue between glass sheet and silicon chip, as shown in Figure 4.

4) silicon chip and standard fiber are partly fixed with ultraviolet glue and base near zone of transition, the standard fiber end connects the FC interface (as shown in figure 10) that is connected with semiconductor laser.

5) regulate laser convergence point step 2) and obtain the different low-light fibre of diameter with the distance that is heated between the optical fiber.

Embodiment 2

1) single-mode fiber is peelled off coated layer;

2) powerful laser is converged on the optical fiber by focus lamp, the heat that laser produces is melted optical fiber, and getting diameter by stretching optical fiber is 10 microns low-light fibre;

3) etching adjacent spaces by photoetching, beam-plasma on the magnesium fluoride substrate is 13 microns, width is 8 microns, the degree of depth is 5 microns a parallel slot, the fine horizontal parallel of low-light is arranged in the parallel slot on the substrate, magnesium fluoride thin plate on low-light fibre array upper cover, fix by ultraviolet glue between magnesium fluoride thin plate and substrate, as shown in Figure 5.

4) magnesium fluoride substrate and standard fiber are partly fixed with ultraviolet glue and base near zone of transition, the standard fiber end connects the FC interface (as shown in figure 10) that is connected with semiconductor laser.

5) regulate laser convergence point step 2) and obtain the different low-light fibre of diameter with the distance that is heated between the optical fiber.

Claims (2)

1, a kind of method that realizes that luminous point connects airtight in the optical fiber solid matter linear array is characterized in that it comprises the steps:

1) end of standard single-mode fiber being drawn out diameter is 5～25 microns low-light fibre, and it comprises standard fiber, zone of transition and low-light fibre;

2) the fine end part interval horizontal parallel of above-mentioned many low-lights is arranged in the surface and is coated with the silicon substrate that has V-shaped groove of magnesium fluoride film or has on the magnesium fluoride substrate of rectangular channel, arrangement pitch is that the fine diameter of low-light adds the fine spacing d of adjacent low-light, wherein, $d\≥\frac{\mathrm{\λ}}{\mathrm{\π}\·n_1\sqrt{\mathrm{si}{n}^2\mathrm{\θ}-(n_2/n_1{)}^2}}$ In the formula: λ is that light is at optical fiber medium wavelength, n ₁Be optical fibre refractivity, n ₂Be air refraction, θ is the incident angle of light in optical fiber;

3) above the low-light fibre on the substrate, be provided with glass sheet or the magnesium fluoride thin plate that the surface is coated with magnesium fluoride film, and fix, form the fine close-packed array of low-light by ultraviolet glue and substrate;

4) the standard fiber end is connected with semiconductor laser by the FC interface, the low-light fibre array end output array of light spots of solid matter.

2. a kind of method that realizes that luminous point connects airtight in the optical fiber solid matter linear array according to claim 1 is characterized in that the drawing method of described low-light fibre is:

1) single-mode fiber is peelled off coated layer;

2) powerful laser is converged on the optical fiber by focus lamp, the heat that laser produces is melted optical fiber, obtains the low-light fibre of thin diameter by stretching optical fiber;

3) regulate laser convergence point and obtain the different low-light fibre of diameter with the distance that is heated between the optical fiber.

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