JPH0850201A - Lens with cell, lens holder, lens material with cell and production for lens with cell - Google Patents

Abstract

PURPOSE:To realize a lens with a cell which has a desired surface shape and is held in optical axis alignment to the cell. CONSTITUTION:Solidifiable viscous fluid 30 is put between the prescribed surface shape and the inside wall of the hole part of the lens material with the cell formed by fixedly fitting and holding the lens material 10 having the prescribed surface shape and having the shape exactly fitting to the shape of the hole part into the hole part of a lens holder 20 to be formed as the lens cell. Natural force is acted on the viscous fluid 30 to form its free surface to the prescribed surface shape which is axisymmetrical and is different from the surface shape of the lens material 10. The viscous fluid is solidified to form its free surface as a reference surface 30A. The solidified viscous fluid and the lens material are subjected to physical anisotropic etching. The desired surface shape 10A with the reference surface 30A as a starting shape is thus formed as the surface shape of the lens material 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens with a cell, a lens holder, a lens material with a cell, and a method for producing a lens with a cell.

[0002]

2. Description of the Related Art A so-called "aspherical surface" has come to be used as a lens surface shape. It is not easy to create an aspherical surface by mechanical polishing, and it is often produced by molding using a mold.

Therefore, for example, most aspherical lenses are manufactured as plastic molded products using a plastic material, and there is a problem that there is little room for selection of materials.

The "glass pressing method" is known as a technique for creating a desired surface shape on a glass surface by using a mold, but the mold used has a high temperature (6
(50 degrees or more) ・ It must withstand high pressure and must also be resistant to oxidation at high temperatures. Therefore, the material of the mold is limited to special metals and ceramics, but such special material is very difficult to process the mold, and in addition, in order to add oxidation resistance, Si ₃ N ₄ , SiC, A
It is necessary to form a thin film of u, Pt, or the like.

For this reason, the "mold" used in the glass pressing method is high in cost and used at high temperature and high pressure, so that the "life as a mold" is not so good even though the material is selected. Not long.

On the other hand, as a method of creating a refracting surface without using molding or polishing, a layer of photoresist is formed on the surface of an optical material, and this layer is patterned into a circle or an ellipse.
Then, by heating the above layer, the surface of the photoresist is made into a curved surface shape by the thermal flow of the photoresist, and thereafter, the photoresist and the optical material are etched so that the curved surface shape of the photoresist surface is made optically. A method of engraving on a material has been proposed (for example, Japanese Patent Laid-Open No. Hei 5).
-173003 gazette: Claim 16).

This method is suitable as a method for forming a lens surface of a microlens, but it is not always easy to control the surface shape produced on the photoresist surface by heating.
It is difficult to form a curved surface exactly as intended.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a lens with a cell having a desired surface shape and held by aligning the optical axis of the cell. (Claim 6).

Another object of the present invention is to provide a method for manufacturing the lens with cells (claims 1 to 5).

Another object of the present invention is to provide a lens material with a cell and a lens holder for manufacturing the lens with a cell (claims 7 to 10).

[0011]

The "method for producing a lens with a cell" of the present invention "has a predetermined surface shape in the hole-like portion of the lens holding body to be the lens cell, and has the shape of the hole-like portion. A solid viscous fluid is put between the above-mentioned predetermined surface shape and the inner wall of the hole of the lens material with cells, in which the lens material of the shape that fits closely is fixedly fitted and held, and this viscous fluid By applying a natural force, the free surface is formed into a predetermined surface shape that is axially symmetric and different from the surface shape of the lens material, the viscous fluid is solidified, and the free surface is used as a reference surface,
By performing physical anisotropic etching on the solidified viscous fluid and the lens material, and forming a desired surface shape having the reference surface as the starting shape as the surface shape of the lens material,
A lens with a cell in which a lens having a desired surface shape is fixed to a lens cell is manufactured "(claim 1).

The lens material held in the hole-shaped portion of the lens holder is to be a lens in the end, so that it is a transparent body and is capable of the above-mentioned physical anisotropic etching. Can be used without any particular restrictions. For example,
Glass, quartz, synthetic quartz, plastic and various single crystal materials can be used.

The "predetermined surface shape" of the lens material may be a flat surface, a concave surface or a convex surface, and the convex or concave surface shape may be various shapes such as a spherical surface and a conical surface.

Further, the "hole-shaped portion" formed in the lens holder may be a columnar shape or a "square columnar shape" such as a quadrangular prism or a hexagonal prism. The hole portion may or may not penetrate.

The "solidifying viscous fluid" is solidified by the action of heat and / or light, and has a "predetermined surface shape which is axisymmetric and different from the surface shape of the lens material" formed as described above. The resin has a viscosity that can be maintained for a while while it is necessary for solidification, and for example, various resist materials such as a commercially available ultraviolet curable resin and a photoresist for photolithography can be preferably used.

As the "viscous fluid" which is hardened by the action of light, an epoxy resin, an acrylic resin, a urethane resin, a modified silicone resin, or a mixture composed of these bases is used. it can. In particular,
A mixture of epoxy resin and acrylic resin is preferable.

As the "viscous fluid" which is cured by the action of heat, epoxy resin, phenol resin, urea resin, melamine resin and the like can be used.

The "natural force" acting on a viscous fluid is
It is not a mechanical force such as pressing a "mold" but a force acting according to the law of nature when the viscous fluid is in a stationary state or a rotating state.

For example, the natural force acting on the viscous fluid is
It can be "pressure by air pressure, gravity and surface tension" (Claim 2), in which case the top of the lens material held in the hole of the lens holder and the upper end of the hole. Relationship between the height of the hole, the ease of wetting of the inner wall of the hole with the viscous fluid, the viscosity of the viscous fluid, the surface tension, and the diameter of the hole in the lens holder (for example, if the diameter of the hole is large, the viscosity The surface shape of the fluid is “planar” except for the vicinity of the wall surface of the hole, and if the diameter is small, the effect of the capillary phenomenon due to surface tension appears.) Therefore, it becomes a planar shape or a convex or concave meniscus shape. Become.

Alternatively, the natural force can be "pressure by air pressure, gravity, surface tension, viscous force and centrifugal force" (claim 3), and in this case, various curved surfaces are used as the surface shape of the viscous fluid. For example, a quadric surface or the like can be formed.

In the method for producing a lens with cells according to claim 1, 2 or 3, when performing physical anisotropic etching from a reference surface which is the surface shape of the solidified viscous fluid, a "selection ratio" is set. Alternatively, the selection ratio may be different from 1, or the selection ratio may be changed continuously and / or stepwise (claim 4).

The "physical anisotropic etching" is
Dry etching such as RIE or ECR plasma etching is suitable.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a lens with a cell, wherein a transparent spherical body is press-fitted into the hole of a lens holder having a cylindrical hole penetrating therethrough, and a surface of the transparent spherical body and an inner wall of the hole are formed. A solid viscous fluid is inserted between them, and the lens holder and the transparent sphere are rotated as a unit around a vertical line passing through the center of the transparent sphere, and the air pressure, gravity, surface tension, viscous force acting on the viscous fluid And a free surface of the viscous fluid by a centrifugal force is formed into a predetermined curved surface which is axisymmetric and different from the surface shape of the lens material, and the viscous fluid is solidified to form the curved surface as a reference surface, and then the reference surface is While performing physical anisotropic etching as the starting shape, the selection ratio is adjusted according to the target lens surface shape, and a desired aspherical surface shape is formed as the lens surface. "

The "lens with cell" of the present invention is a lens with a cell manufactured by any one of the methods for manufacturing a lens with a cell described in claims 1 to 5 (claim 6).

The "lens material with cells" of the present invention is
“A lens material having a predetermined surface shape in the hole-shaped portion of the lens holder to be the lens cell, and having a shape that fits exactly into the shape of the hole-shaped portion, the surface shape becomes the bottom of the hole-shaped portion. It is fixedly fitted and held as described above (Claim 7).

The lens holder is preferably made of a material which is not etched or is not so much etched by the above-mentioned physical anisotropic etching, or a "film of a material which is not etched" is formed on the surface. Specifically, S
US-based material, duralumin-based material, or metal or ceramic material subjected to Cr surface treatment or Ti surface treatment is suitable.

There are various possible combinations of the lens holder and the lens material. For example, the hole-like portion of the lens holder is a cylindrical hole formed by penetrating the lens holder.
The lens material fitted in the hole portion may be a transparent sphere (claim 8).

In the lens material with cells according to the eighth aspect, "the opening of the hole-like portion of the lens holder is a cylindrical surface having a diameter larger than that of the fitting portion (with the transparent spherical lens material). And a groove having the axial direction of the hole-shaped portion as the depth direction is formed in the diameter difference portion between the fitting portion and the opening "(claim 9).

The "lens holder" of the present invention is a lens holder used for the lens-equipped lens material according to claim 9, that is, "the opening of the hole-like portion of the lens holder is (a transparent spherical body). It has a cylindrical surface with a diameter larger than the fitting part (with the lens material), and a groove whose axial direction is the depth direction of the hole is formed in the difference in diameter between the fitting part and the opening. It is a lens holder (claim 10).

The method of manufacturing a lens with a cell of the present invention is extremely suitable for manufacturing a minute lens having a minute lens surface of several mm or less, which will be described later as an embodiment.

In the present invention, a lens with cells is realized, but a material (not necessarily transparent) is held in the lens holder, and a desired process is performed in the same process as the lens surface formation. The curved shape of is formed on the material,
It should be noted that this curved surface shape can be used as it is, or a reflective film can be formed on this curved surface shape to form a “reflection surface”, and by doing so, a “reflection optical element” with cells can be realized.

[0032]

In FIG. 1A, reference numeral 20 indicates a lens holder, reference numeral 10 indicates a transparent sphere which is a lens material, and reference numeral 3
0 indicates a solidifying viscous fluid.

The lens holder 20 has a hole portion penetrating and penetrating in a "cylindrical shape", and the transparent spherical body 10 is press-fitted into this portion, fitted tightly and fixedly held. That is, what is shown is an example of the lens material with cells according to claim 8.

The solidifying viscous fluid 30 is contained between the transparent sphere 10 and the inner wall of the cylindrical hole. In this state, as shown in FIG. 1B, when the lens holder 20 and the transparent sphere 10 are integrally rotated about the vertical line 40 passing through the center of the transparent sphere 10, the viscous fluid 30 will be
As natural forces, in addition to viscous forces that act inside the fluid, air pressure, gravity, surface tension, and centrifugal force due to rotation act symmetrically with respect to the above axes.

Since the action of the centrifugal force acts to move the viscous fluid away from the shaft, a part of the viscous fluid overflows the outside of the hole, and the action of the natural force causes the surface as shown in FIG. A shape 30A is obtained. This surface shape 30A
Is axisymmetric with respect to the vertical line and has a curvature different from the surface of the transparent sphere 10.

Subsequently, heat and / or light is applied to the viscous fluid 30 to solidify the viscous fluid 30 and the surface shape 3
Fix 0A. As a result of solidification, the surface shape 30A
However, the shape before solidification may be slightly changed. In this case, the surface shape is formed by allowing for the deformation at the solidification stage in advance so that the desired “reference surface” shape can be obtained after the solidification.

The shape of the reference surface is determined by the diameter of the transparent sphere 10, the opening of the hole of the lens holder 20 and the step between the surface of the transparent sphere 10, the material and viscosity of the viscous fluid 30, the rotational speed, etc. By appropriately setting, the shape of the reference surface can be easily and reliably controlled.

The surface of the viscous fluid thus solidified is the "reference surface", and physical anisotropic etching is performed using this reference surface as the starting shape.

For example, when the etching is performed under the condition that the selection ratio is 1, that is, the rate of "etching" in the etching is the same in the solidified viscous fluid and the transparent sphere, the anisotropic etching is performed on the object. Since it is engraved in a direction orthogonal to the surface, as shown in FIG. 1C, the transparent spherical body 10 has a convex surface (having a curvature smaller than the initial curvature of the transparent spherical body 10) having a shape substantially similar to that of the reference surface 30A. A surface shape 10A is obtained. This surface shape 10A is used as a refracting surface.

Although the case where the convex curved surface is formed as the reference surface has been described above, the shape of the reference surface is not limited to this.

As shown in FIG. 2A, the lens holder 2
By deepening the hole in which the viscous fluid 30 is put in 1, it is possible to form a "rotational parabolic" reference surface as shown in the figure by the action of the centrifugal force due to the rotation. If no centrifugal force is applied, a flat reference surface can be obtained as shown in FIG. Figure 2 (c) shows
The case of the reference surface having the same convex curved surface as that described in FIG. 1B is shown.

For example, when a physically anisotropic etching with a selection ratio of 1 is performed using a reference surface as shown in FIG. 2A as a starting shape, a concave curved surface is formed regardless of the surface shape of the lens material. It can be formed on a lens material, and if anisotropic etching is performed from a planar reference surface as shown in FIG. 2B at a selection ratio of 1, a flat surface can be formed on the lens material regardless of the surface shape of the lens material. Can be formed into

As described above, in the present invention, since the shape of the "reference surface" as the starting shape for etching is performed by the action of "natural force", not by the mechanical force such as pressing of the die, the viscous fluid If the material, the shape of the hole in the lens holder, the surface shape of the lens material, the rotation speed, etc. are determined, the reference surface having the same shape can be always realized.

In the description with reference to FIG. 1, the case where the physical anisotropic etching is performed with a selection ratio of 1: has been described, but by changing the selection ratio from 1 or changing it with time, The lens surface shape finally formed on the lens material can be various aspherical shapes.

Referring to FIG. 3, (a) shows a state in which the reference surface shown in FIG. 2 (c) is formed in the viscous fluid (solidified) 30 on the transparent sphere 10. The upper half of the transparent sphere 10 is covered with the solidified viscous fluid.

When physical anisotropic etching is performed from this state, the solidified viscous fluid 30 is uniformly etched until the top of the transparent sphere 10 appears, regardless of the selection ratio. From the stage where the top of the transparent sphere 10 appears, the etching rate of the transparent sphere 10 and the solidified viscous fluid 30 is determined by the selection ratio.

That is, the selection ratio is [etching rate of the transparent sphere 10] / [etching rate of the solidified viscous fluid 30].
The relative etching rate of 0 and the solidified viscous fluid 30 is determined. Therefore, the surface shape of the etching result can be controlled by the setting condition of the selection ratio.

The relationship between the selection ratio and the surface shape of the etching result will be described as a model with respect to the case of FIG.

FIG. 8A schematically shows the state where the top of the transparent sphere 10 is exposed for the first time from the state of FIG. 3A to anisotropic etching. For easy understanding of the description, the spherical shapes of the surface of the transparent sphere 10 and the surface of the solidified viscous fluid 30 are shown as “stepwise”. The step of the "stairs representing the surface shape" corresponds to the curvature of the surface shape.
The step of “stairs” that represents the continuous inclination of the surface shape of the solidified viscous fluid 30 is smaller than the step of “stairs” that represents the continuous inclination of the surface of the transparent sphere 10, that is, the surface of the solidified viscous fluid 30. Indicates that the curvature of is smaller than the curvature of the surface of the transparent sphere 10.

FIG. 8 shows the progress of engraving when anisotropic etching is performed with a selectivity of 0.5. The progress of engraving due to etching changes with time. , (A) to (d) of FIG.

Since the solidified viscous fluid 30 is eroded at a speed twice as fast as that of the transparent sphere 10, the top of the transparent sphere 10 and
The “height difference” from the surface of the solidified viscous fluid 30 at the right end of the figure is “ΔH” as shown in FIG. 8 (a) at first, but gradually increases with time, and as shown in FIG. 8 (d). In this state, it has expanded to 1.3 times the original size.

This means that, as a result of etching, the radius of curvature of the curved surface formed on the transparent sphere 10 becomes larger than the curvature of the surface of the solidified viscous surface 30 which initially covered the surface of the transparent sphere 10. Means that.

That is, the "selection ratio smaller than 1" acts to make the curvature of the curved surface formed on the transparent sphere larger than the "curvature of the reference surface".

FIG. 9 shows the progress of erosion when anisotropic etching is performed with a selection ratio of 1.5, over time, following FIG. 8, and with the progress of time, The etching condition by etching progresses sequentially from (a) to (d) of FIG.

Since the transparent sphere 10 is eroded at a speed 1.5 times faster than the solidified viscous fluid 30, the "high" between the top of the transparent sphere 10 and the surface of the solidified viscous fluid 30 at the right end of the figure. Initially, the difference of “Sa” is “Δ” as shown in FIG.
Although it is "H", it gradually decreases as time passes, and
In the state of (d), it is reduced to 0.7 times the original size.

This means that, as a result of etching, the radius of curvature of the curved surface formed on the transparent sphere 10 is smaller than the curvature of the surface of the solidified viscous surface 30 which initially covered the surface of the transparent sphere 10. Means that.

That is, the "selection ratio larger than 1" acts to make the curvature of the curved surface formed on the transparent sphere smaller than the "curvature of the reference surface".

Referring again to FIG. 3, FIG.
When physical anisotropic etching is performed from the state of (a) and the top of the transparent sphere 10 appears, physical anisotropic etching is performed, for example, with a selection ratio of 0.5. Since the fluid 30 is eroded at a speed twice as fast as that of the transparent sphere 10, if etching is performed for a while, the top of the transparent sphere 10 is removed from the solidified viscous fluid 30 as shown in FIG. 3B. You will get a state of being dug up.

Since the top of the transparent sphere 10 is also slightly etched, the radius of curvature near the axis shown by the chain line is larger than that of the original spherical surface, but this radius of curvature is
It is smaller than the radius of curvature of the surface of the solidified viscous fluid 30 when the top of the transparent sphere 10 starts to be exposed.

Then, when the selection ratio is gradually increased, the curvature of the surface formed on the transparent sphere 10 is changed thereafter so as to decrease the curvature of the surface of the solidified viscous fluid 30.

For example, if anisotropic etching is continued with the selection ratio set to 2, finally, the shape as shown in FIG. 3C, that is, the curvature at the top is large (this is initially
The result is that the selection ratio is reduced to 0.5), and a surface having a smaller curvature is obtained toward the periphery (this is the result of increasing the selection ratio to 1 or more).

FIG. 3 is an example, and it is possible to obtain a desired aspherical shape as the final shape by controlling the selection ratio during etching.

The control of the selection ratio can be realized by computer control. For example, the surface shape of the solidified viscous fluid 30 in FIG.
(C) Assuming that the surface shape of the lens material 10 is the target shape, the procedure proceeds as follows as an example.

First, a parameter for controlling the selection ratio is determined, and a computer simulation is performed on how to control the above parameters in order to obtain the target shape from the starting shape.

That is, it is investigated how the surface shape of the lens material changes according to various temporal changes in the above parameters, and the surface shape change from the starting shape to the target shape is traced by simulation. , Find out what kind of selection ratio control is most suitable.

Next, while temporally changing the selection ratio thus obtained by actually changing the parameters,
Experiments are performed to correct control conditions and determine control conditions that can actually obtain the target shape from the starting shape.

It is only necessary to program the control conditions determined in this way and program-control the "selection ratio control" in an actual etching apparatus.

Of course, the reference surface shape (FIG.
By combining the shapes of (a) and (b)) with the selection ratio control, and according to the surface shape of the lens material, various aspherical shapes can be created regardless of whether they are convex curved surfaces or concave curved surfaces. It is possible.

Control of physical anisotropic etching is easier than that of chemical etching, and moreover, if the control of the selection ratio is the same for the same starting shape, the same target shape will always be obtained. As a result. That is, physical etching has excellent reproducibility.

Incidentally, in the state where the lens surface shape of the target shape is obtained on the lens material, it is usual that the solidified viscous fluid still remains on the surface of the lens material. This residue may be removed by a means such as washing, or the residue itself can be used as an aperture for the lens surface if a light-shielding material is selected and used as the viscous fluid in advance.

[0071]

EXAMPLES Specific examples will be described below.

Example 1 A coupler lens for optical communication (a lens for condensing a light beam from an LD light source on a core portion of an incident end face of an optical fiber) having a coupling efficiency of 58% was designed as follows. .

First surface (light source side): spherical surface (curvature radius: 1.
5 mm), 2nd surface (optical fiber side): aspherical surface (light ray effective diameter: 1.6 mmφ), material: SF60 (wavelength: 0.8)
Refractive index for light of 3 μm: 1.78278).

Reference numeral 22 in FIG. 4 indicates a lens holder. The lens holder 22 is made of SUS316 material and has a cross-sectional shape as shown in FIG.

The lens holder 22 is an embodiment of the lens holder according to the tenth aspect. That is, although a cylindrical hole-shaped portion is pierced and penetrated, the opening of the hole-shaped portion is a cylindrical surface 22A having a diameter larger than that of the fitting portion with the lens material. A groove 22B is formed in the diameter difference portion between and with the axial direction of the hole-shaped portion as the depth direction.

A transparent sphere 11 having a diameter of 3 mm according to SF60 is press-fitted into the fitting portion of the hole-like portion of the lens holder 22 as described above, and the "lens material with cell (claim 9 ) ”

As shown in FIG. 4, the second part of the transparent sphere 11 is
With the side on which the surface is to be formed facing upward, first, a primer was applied to the surface of the transparent sphere to perform a primer treatment. At this time, post-baking is preferable.

Next, 1.7 cc of a resist material (OFPR-800 manufactured by Tokyo Ohka Co., Ltd.) was used as the solidifying viscous fluid 30, and a precision volume lightweight pump was provided between the lens holder 22 and the transparent sphere 11. (Prebar made by Hibar
It was quantitatively applied (application accuracy: ± 0.5%) using a sion pump CV series.

The lens holder 22 was set as a jig in a spinner, and was rotated about a vertical line (chain line in FIG. 4) passing through the center of the transparent sphere 11 as an axis to gradually increase the rotation speed to 300 RPM. Excessive viscous fluid escaped to the groove 22B side due to the action of the centrifugal force due to the rotation, and became a surface shape as shown in FIG.

Next, the lens holder 22 was heated in an oven at a temperature of 150 ° C. for 30 minutes and post-baked. As a result, the surface shape of the solidified viscous fluid 30 was a spherical surface having a radius of curvature of 1.733 mm within the lens effective diameter range. This is the "reference plane". That is, the surface shape of the solidified resist material has a radius of curvature larger than the radius of curvature (1.5 mm) of the surface of the transparent sphere 11.

The shape of the reference surface is away from the axis shown by the chain line in FIG. 4 and deviates from the spherical shape outside the effective diameter, but the desired aspherical surface is well formed within the effective diameter. It is sufficient if possible, and other ranges may be out of shape.

[0082] "aspherical" should be formed as a second surface of the transparent spheres 11, wherein Z = known aspherical ^{(1 / R) h 2 /} {1 + √ [1- (K + 1) (1 / R)
² h ² ]} + Ah ⁴ + Bh ⁶ + Ch ⁸ R: radius of curvature on optical axis h: distance from optical axis K: conical constant A, B, C: 4th, 6th and 8th aspherical coefficients, respectively Z: in the optical axis direction of the distance from the lens vertex, and R = -1.50025mm K = -0.9995306 a = -0.8403612 × 10¯ 2 B = 0.2488880 × 10¯ 1 C = 0.0 It has a shape.

Since the aspherical surface has a negative conical constant: K, it is basically an elliptical surface rotationally symmetric with respect to the major axis. As an aspherical surface type, the curvature in the vicinity of the optical axis is large (the radius of curvature is small). ), The curvature is smaller (the radius of curvature is larger) as the distance from the optical axis increases.

Therefore, it is preferable to control the selection ratio so that the selection ratio is small at the beginning and gradually increases. After the above post-baking, a dedicated jig for the lens material with cells was set in the ECR plasma etching apparatus, Ar, CHF ₃ , and O ₂ gas were introduced, and under the condition of 2 to 3 × 10 to ⁴ Torr for 500 minutes. Anisotropic etching was performed.

As the parameter for controlling the selection ratio, "amount of oxygen and Ar introduced" is used.
A selection ratio control program was determined by simulation and experiment and controlled by a computer.

The condensing state of this lens is, for example, as illustrated in FIG. As shown in FIG. 7, LD light source 1 (oscillation wavelength: 0.83 μm, full angle at half maximum of emitted light: 32 degrees)
Between the LD light source 1 and the lens first surface: 0.55 mm, and the distance between the lens second surface and the optical fiber-2 entrance end surface: 8.7489. When the cell 22 was placed in the column (the cell 22 was fixed to the lens barrel), a coupling efficiency of 57% was obtained. The first lens
The surface distance between the surface and the second surface is 2.979 mm.

Example 2 As in Example 1 above, the following was designed as a coupler lens for optical communication.

Coupling efficiency: 58%, First surface (light source side): Spherical surface (curvature radius: 1.0 mm, effective ray diameter: 0.48 mm)
φ), second surface (optical fiber side): aspherical surface (light ray effective diameter: 1.10 mmφ), material: SF60 (wavelength: 1.3)
Refractive index for light of μm: 1.76817).

Reference numeral 23 in FIG. 5 indicates a lens holder. The lens holder 23 is made of SUS316 material and has a cross-sectional shape as shown in FIG.

The lens holder 23 is another embodiment of the lens holder described in claim 10. That is, although a cylindrical hole-shaped portion is pierced and penetrated, the opening of the hole-shaped portion is a cylindrical surface 23A having a diameter larger than that of the fitting portion with the lens material. A groove 23B is formed in the difference in diameter with the groove 23B whose depth direction is the axial direction of the hole-shaped portion.

A transparent sphere 12 having a diameter of 2 mmφ according to SF60 is press-fitted into the fitting portion of the hole-like portion of the lens holder 23 as described above, and as shown in FIG. ) ”

As shown in FIG. 5, the second part of the transparent sphere 12 is
First, with the side on which the surface is to be formed facing upward, a primer was first applied to the surface of the transparent sphere to perform a primer treatment, and post baking was performed.

Next, as the solidifying viscous fluid 30, 0.3 cc of a resist material (OFPR-800 manufactured by Tokyo Ohka Co., Ltd.) was used, and the precise volume and light weight were provided between the lens holder 23 and the transparent sphere 12. It was quantitatively applied using a pump (application accuracy: ± 0.5%).

The lens holder 23 was set as a jig on a spinner and rotated about a vertical line (chain line in FIG. 5) passing through the center of the transparent sphere 12 as an axis to gradually increase the rotation speed to 300 RPM. Excessive viscous fluid escaped to the groove 23B side by the action of the centrifugal force due to the rotation, and became a surface shape as shown in FIG.

Next, the lens holder 23 was heated in an oven at a temperature of 150 ° C. for 30 minutes and post-baked. As a result, the surface shape of the solidified viscous fluid 30 was a spherical surface having a radius of curvature of 1.11 mm within the lens effective diameter range. This is the "reference plane". That is, the surface shape of the solidified resist material has a radius of curvature larger than the radius of curvature (1.0 mm) of the surface of the transparent sphere 12.

The "aspherical surface" to be formed as the second surface of the transparent sphere 12 is R = -1.00 mm K = -0.1071166 × 10 ¹ A = 0.481868 × 10 in the above-mentioned aspherical surface formula. ~ is a shape with ^{2 B = -0.3087594 × 10 ~ 1} C = 0.3821575.

Since this aspherical surface has a conic constant: K smaller than -1, it is basically a "hyperboloidal surface". As a shape type, "a curvature is large in the vicinity of the optical axis (a radius of curvature is small) and the optical axis leaves As a result, the curvature becomes smaller (the radius of curvature becomes larger).

After the above post-baking, a dedicated jig for lens material with cells was set in the ECR plasma etching apparatus, and Ar, CHF ₃ , O ₂ gas was introduced, and 2 to 4 × 10 to ⁴
Anisotropic etching was performed under Toor conditions while changing the etching conditions with time. That is, until the end of the etching scan start, the selection ratio while slightly decreasing the O ₂ gas introduction rate in the introduction gas, 0.05-2.
In the range of 0, etching was performed for 420 minutes while initially being small and gradually increasing with the passage of time. Similar to the lens in Example 1, this lens was used to measure the coupling efficiency with an optical coupling efficiency measuring device in a usage state as shown in FIG. 6 (LD full angle at half maximum 32 °, distance between LD light source and lens first surface: 0.385 mm, the distance between the second surface of the lens and the incident end surface of the optical fiber: 5.927 mm was arranged (every cell 23 was fixed to the lens barrel), and it was 57%.
The coupling efficiency of was obtained. The surface distance between the first surface and the second surface of the lens is 1.983 mm.

Example 3 As in Example 2 above, the following was designed as a coupler lens for optical communication.

Coupling efficiency: 58%, first surface (light source side): spherical surface (radius of curvature: 1.0 mm, effective diameter of light beam: 0.3 mm)
φ), second surface (optical fiber side): aspherical surface (light ray effective diameter: 1.12 mmφ), material: SFS1 (wavelength: 1.3)
Refractive index for light of μm: 1.87367).

The lens holder 23 shown in FIG. 5 (Example 2)
(Same as the one used in S.)
According to the above, a transparent sphere having a diameter of 2 mmφ was press-fitted to obtain “lens material with cells (claim 9)”.

The aspherical surface shape of the second surface is R = -1.00 mm K = -0.9700838 A = -0.3066428 × 10 to ² B = 0.1118117 × 10 to ^{2 in the} above aspherical expression. The shape is such that C = 0.2645559, and the curvature is large in the vicinity of the optical axis (small radius of curvature) and becomes small as the optical axis is separated (large radius of curvature).

As in Example 2, a resist material was used as a viscous fluid, and a spherical surface having a curvature radius of 1.11 mm was formed as a "reference surface", and the selection ratio was initially small within the range of 0.05 to 2.0. The aspherical surface was formed by computer control so that it gradually increased with the passage of time.

Similar to the lens in Example 1, this lens was used to measure the coupling efficiency with an optical coupling efficiency measuring apparatus in the use condition as shown in FIG. 6 (LD full angle at half maximum 32 °, LD light source and lens first surface). Interval: 0.29 mm, second lens
Between the surface and the incident end surface of the optical fiber: 5.427 mm
When the cells were arranged so as to be as follows (the cell 23 was fixed to the lens barrel), a coupling efficiency of 57% was obtained. The surface distance between the first surface and the second surface of the lens is 1.990 mm.

In the third embodiment, SFS1 of the lens material is used.
However, since the material used in Example 2 has a higher refractive index than SF60, it requires less aspherical surface processing allowance, and the etching time is only 230 minutes, which is 190 minutes shorter than the etching time in Example 2 of 420 minutes. Was done. That is, it is possible to efficiently manufacture a desired lens, and it is possible to reduce the manufacturing cost of the lens.

The lens holder 2 used in Example 1
2, the lens holding body 23 used in Examples 2 and 3 is compared with the lens holding body 20 shown in FIG. 1 in the case of forming a convex reference surface. (B)
As shown in, the curved surface has a shape that is rolled up at a portion near the inner wall of the hole-shaped portion of the lens holder 20,
When this tendency becomes remarkable, the area of the portion having the “predetermined shape” on the formed reference surface may be small. However, in the lens holders 22 and 23 of FIGS. As shown, a clean reference surface is formed inside the mating surface, and a considerable part of the shape of this reference surface has a predetermined shape.

That is, the lens holder according to claim 10 is
It enables the formation of a highly accurate reference surface.

Further, after the reference surface is formed, the lens material held by the lens holder can be simultaneously etched in units of 100 pieces.

[0109]

As described above, according to the present invention, it is possible to provide a novel lens with a cell, a lens holder, a lens material with a cell, and a method for manufacturing a lens with a cell.

According to the method of manufacturing a lens with a cell according to the first to fifth aspects, a predetermined reference surface is formed without using a special "die", and a desired anisotropic anisotropic physical etching is performed. Since the surface shape of is formed on the lens material,
It is possible to realize an accurate lens with a cell.

Further, the surface shape and the reference surface shape of the lens material can be adjusted according to the target shape to be formed in the lens material, the substantial amount of etching processing can be reduced, and the etching time can be shortened. .

Since the lens with cells according to claim 6 is manufactured by the method according to any one of claims 1 to 5, it is easy to manufacture, low in cost, good in mass productivity, and substantially as designed. realizable. Further, the lens material has only to have a large degree of freedom in selection of materials and a large degree of freedom in optical design, as long as it is capable of physically anisotropic etching. Further, since the lens held in the cell has its optical axis aligned with the cell, it is easy to align the optical axis when it is assembled to the optical device.

The lens material with cells according to claims 7 to 9 facilitates the implementation of the method according to claims 1 to 5.

In the lens holder according to the tenth aspect, a highly accurate reference surface can be formed as the surface shape of the solidifying viscous fluid.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a method of manufacturing a lens with cells according to the present invention.

FIG. 2 is a diagram for explaining a reference surface formed in a solidifying viscous fluid.

FIG. 3 is a diagram for explaining a process of forming a desired surface shape on a lens material by etching using a reference surface as a starting shape.

FIG. 4 is a diagram for explaining a lens material with cells in Example 1.

FIG. 5 is a diagram for explaining a lens material with cells in Example 2.

FIG. 6 is a diagram illustrating a condensed state of a coupler lens for optical communication which is a target to be implemented in Examples 1 and 2.

FIG. 7 is a diagram for explaining a usage state of a coupler lens for optical communication.

FIG. 8 is a diagram for explaining the effect of anisotropic etching with a selection ratio smaller than 1 on the shape of the surface formed on the transparent sphere.

FIG. 9 is a diagram for explaining the effect of anisotropic etching with a selection ratio greater than 1 on the shape of the surface formed on the transparent sphere.

[Explanation of symbols]

 10 Transparent Sphere (Lens Material) 20 Lens Holder to Become a Lens Cell 30 Solidifying Viscous Fluid 30A Reference Surface 30B Desired Surface Shape Formed as Lens Surface

Claims (10)

[Claims] Claim: What is claimed is: 1. A lens material, which is to be a lens cell, has a hole-shaped portion, and a lens material having a predetermined surface shape and having a shape that fits exactly into the hole-shaped portion is fixedly fitted and held. In the lens material with cells, between the predetermined surface shape and the inner wall of the hole-like portion, a solidifying viscous fluid is put, a natural force is applied to the viscous fluid, and its free surface is axisymmetric, In addition, it is formed into a predetermined surface shape different from the surface shape of the lens material, the viscous fluid is solidified, and its free surface is used as a reference surface, and the solidified viscous fluid and the lens material are physically anisotropic. By performing etching to form a desired surface shape having the reference surface as a starting shape as the surface shape of the lens material, a lens having a desired surface shape is formed into a lens with a cell fixed in a lens cell. Special to manufacture Cell with a lens manufacturing method according to. 2. The method for manufacturing a lens with a cell according to claim 1, wherein the natural forces acting on the viscous fluid are air pressure, gravity and surface tension. 3. The method for manufacturing a lens with cells according to claim 1, wherein the natural force acting on the viscous fluid is air pressure, gravity, surface tension, viscous force and centrifugal force, and the reference surface formed is a curved surface. A method of manufacturing a lens with a cell, characterized in that 4. The method for manufacturing a lens with a cell according to claim 1, 2 or 3, wherein, when performing physical etching, the selection ratio is different from 1 or the selection ratio is changed continuously and / or stepwise. A method of manufacturing a lens with a cell, comprising: 5. A transparent spherical body is press-fitted into the hole of a lens holder having a cylindrical hole penetrating therethrough, and a solidifying viscous fluid is introduced between the transparent spherical body and the inner wall of the hole to make it transparent. The lens holder and the transparent sphere are integrally rotated about a vertical line passing through the center of the sphere, and the free surface of the viscous fluid is moved by the air pressure, gravity, surface tension, viscous force and centrifugal force acting on the viscous fluid. , Which is axisymmetric and has a predetermined curved surface different from the surface shape of the lens material, solidifies the viscous fluid to form the curved surface as a reference surface, and then uses the reference surface as a starting shape to achieve a physical anisotropy A method for manufacturing a lens with a cell, wherein a desired aspherical shape is formed as a lens surface by adjusting a selection ratio in accordance with a target lens surface shape while performing a property etching. 6. A lens with a cell manufactured by the method for manufacturing a lens with a cell according to claim 1, 2, 3 or 4 or 5. 7. A lens material, which has a predetermined surface shape, is fixedly fitted and held in a hole-shaped portion of a lens holder that is to be a lens cell. Lens material with closed cells. 8. The lens material with cells according to claim 7, wherein the hole-like portion of the lens holder is pierced and penetrated in a cylindrical shape, and the lens material fitted in the hole-like portion is a transparent spherical body. Lens material with cells characterized by: 9. The lens material with cells according to claim 8, wherein the opening of the hole-shaped portion of the lens holding body is a cylindrical surface having a diameter larger than that of the fitting portion, and the fitting portion and the opening portion are separated from each other. A lens material with a cell, wherein a groove having an axial direction of the hole-shaped portion as a depth direction is formed in the diameter difference portion. 10. A lens holder used in the lens material with cells according to claim 9.