JPH08220357A - Optical connecting device and its production - Google Patents

Abstract

PURPOSE: To provide an optical connecting device and its production for increasing the degree of freadom of optical connection. CONSTITUTION: This optical connecting device consists of an optical transmission substrate 12 in which graded index type rod lenses 10 are stacked and arranged in lots of parallel lines, a planer microlens array substrate 16 fixed to the substrate 12, and optoelectronic parts 14 mounted on the surface of the substrate 16. A diffraction optical element 18 is assembled in the optical path. Moreover, a diffraction optical element is assembled between the optical transmission substrate 12 and the planer microlens array substrate 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical wiring board in which a graded index rod lens and a flat plate microlens array are combined so that optoelectronic components such as a surface emitting laser and a spatial light modulator can be easily integrated and mounted. (Optical bus
(Interconnection System).

[0002]

2. Description of the Related Art While various devices and systems have been proposed and researched in the fields of optical communication, optical switching, optical computing, etc., and gradually put into practical use, research on optical packaging technology has been closed recently. It has been uploaded. If the optical information connection between opto-electronic components (devices) is optical interconnection, the modularization technology such as how to arrange and fix these devices is also an important element of optical interconnection technology. .
In particular, in so-called free space optical interconnection (three-dimensional optical connection) in which a two-dimensional pattern of light is spatially propagated, the optical mounting technique is highly important. This is because free space optical interconnection is expected to have high capability in terms of the amount of information that can be handled, its parallelism, and the degree of freedom of connection, but it has many problems related to modularization and mounting. is there. Specifically, precise alignment adjustment of 6 axes of x, y, z, θ _x , θ _y , and θ _z for each optical system component is required, miniaturization is difficult, temperature change, vibration, etc. The problems are that it is difficult to obtain reliability, and because it is modularized by assembling bulky individual parts, it is difficult to automate and standardize compared to the semiconductor device manufacturing process.

The present applicant has proposed a free space optical system mounting technique that solves the above problems (Japanese Patent Laid-Open No. 6-337319, "Optical connection device and its manufacturing method"). According to the optical connection device such as this already proposed, it is composed of a gradient index rod lens arrayed in multiple stages and multiple rows, and a prism inserted and fixed between them.
A substrate (hereinafter referred to as a light propagating substrate) for image transmission between the conjugate image planes, which has a conjugate image plane on the upper surface of each prism, is provided, and a flat plate microlens is provided on the substrate at each conjugate image plane position. A substrate provided with an array (hereinafter referred to as a flat plate microlens array substrate) is adhesively fixed, and optoelectronic components such as a surface emitting laser and a spatial light modulator are arranged at the focal plane position of each flat plate microlens array. It enables optical connection between them.

Since such an optical connecting device is a hybrid optical system of a gradient index rod lens and a flat plate microlens array, the effect of the aberration of the gradient index rod lens is reduced and high performance is achieved. This enables optical connection of various arrays. Further, since the flat plate microlens array is integrally manufactured on one substrate, each flat plate microlens array position = each conjugate image plane position (optoelectronic component placement position) is manufactured with high position accuracy of photomask accuracy. it can. As a result, solder pads, electrical wiring, etc. for surface mounting of optoelectronic components can be formed on the surface of a flat microlens array substrate with the same photomask accuracy, and optoelectronic systems can be manufactured by mounting each optoelectronic component with high accuracy. Becomes

[0005]

The above-mentioned proposed optical connection device is capable of high-performance array-to-array optical connection, but has a drawback that the degree of freedom of optical connection is small.

An object of the present invention is to rearrange the order of arrays, one-to-many, many-to-one (m).
An object is to provide an optical connection device that enables any-to-one) connection and expands the degree of freedom of optical connection.

Another object of the present invention is to provide a method of manufacturing such an optical connecting device.

[0008]

SUMMARY OF THE INVENTION The optical connecting device of the present invention has a telecentric imaging system as a unit, and at least one or more stages of the imaging system arranged on the same optical axis are arranged in parallel in at least one column. A light propagation substrate arranged in a light-transmissive flat plate, and the light propagation substrate provided on the optical axis in a direction perpendicular to the optical axis, and one surface of the light propagation substrate. At least two optical path changing elements that change the optical path toward the side, and a plurality of flat plate microlens arrays provided on the one surface side of the light propagation substrate and facing the optical path changing elements. A flat plate microlens array substrate, at least one diffractive optical element provided on the optical axis of the image forming system, and a conjugate image plane and / or a Fourier transform plane on the other surface side of the light propagation substrate. At least 2 And a more optoelectronic components.

Further, in the method for manufacturing an optical connecting device of the present invention, a step of forming a groove on the first and second light-transmissive flat substrates by grinding or etching using a diamond blade and bending in the radial direction. A step of arranging a cylindrical long rod lens having a rate distribution in the groove, and integrating and fixing the first and second light-transmissive flat substrates;
The first light-transmissive flat substrate and the rod lens are ground by a diamond blade to leave a part of the second light-transmissive flat substrate in a direction perpendicular to the axis of the rod lens. The step of dividing by cutting into the gradient index rod lens, and the optical path changing element and the first portion in the gap between the gradient index rod lens and the gradient index rod lens formed by the dividing.
And fixing the transmissive diffractive optical element to prepare a light propagation substrate, and a lens surface of the flat plate microlens array facing the optical path changing element of the flat plate microlens array substrate having a plurality of flat plate microlens arrays. A second transmission type diffractive optical element on the side, a step of aligning and fixing the flat microlens array substrate to the light propagation substrate, and a side of the flat microlens array substrate opposite to the microlenses. And a step of mounting an optoelectronic component on the surface.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view for helping understanding of the structure of the optical connecting apparatus of the present invention. The optical connecting device includes a light propagation substrate 12 in which gradient index rod lenses 10 are arranged in multiple rows parallel to each other, a flat microlens array substrate 16 adhered and fixed to the substrate 12, and surface mounted on the substrate 16. And a diffractive optical element 18 in the optical path. A diffractive optical element is also provided between the light propagation substrate 12 and the flat plate microlens array substrate 16, but it is omitted for simplification of the drawing.

The gradient index rod lens has a gradient index distribution that decreases from the center to the outer periphery in the radial direction in a substantially squared manner, and the rays within the rod are bent by the gradient of the gradient index to act as a lens. And is commercially available from Nippon Sheet Glass Co., Ltd. under a registered trademark of SELFOC. The flat plate microlens array is an array of microscopic lenses having a substantially hemispherical shape formed by an ion exchange method near the surface of a glass substrate. In this specification, a substrate including a plurality of such flat plate microlens arrays is referred to as a flat plate microlens array substrate. The microlens array is not limited to this, and may be a diffraction-based microFresnel lens array, a resin-molded spherical lens array, or the like.

FIG. 2 shows a typical one-stage image forming system in such an optical connecting device. The light propagating substrate 12 constituting the one-stage imaging system includes two gradient index rod lenses 101 and 102 telecentricly arranged so as to form an inverted equal-magnification imaging system, and a gradient index rod lens. 101
And a prism 201 provided between the gradient index rod lenses 102 and 104, and a Fourier transform surface between the gradient index rod lenses 101 and 102. The transmission type diffractive optical element 182 is provided, and these are sandwiched between two glass substrates 191 and 192. Further, the flat plate microlens array substrate 16 forming the one-stage image forming system is
The diffractive optical element includes two flat plate microlens arrays 221 and 222 in which a plurality of microlenses are formed in a matrix and transmissive diffractive optical elements 181 and 183 provided on the lens surface of the flat plate microlens array. 181, 183 are provided at positions facing the prisms 201, 202. Flat plate microlens array 181
A light emitting element array 141 is provided at the focal plane position of, and a light receiving element array 142 is provided at the focal plane position of the flat plate microlens array 182. In the light emitting element array 141 and the light receiving element array 142, a plurality of light emitting elements and light receiving elements are arranged in a matrix.

In the image forming system as described above, the light emitting surface of the light emitting element array 141 and the light receiving surface of the light receiving element array 142 form a conjugate image plane, and the light of the light emitting element array 141 is divided into two parts.
The dimensional pattern is propagated to the light receiving element array 142.

In the configuration of FIG. 2, the prism 202 is
If a light path changing element including a quarter wave plate, a polarization beam splitter and a mirror is replaced, and the light receiving element array 142 is replaced with a spatial light modulation device, a two-dimensional pattern of light is modulated and propagated to the next-stage imaging system. can do.

Various optoelectronic components surface-mounted on the flat microlens array substrate 16 can be selected according to the application of the optical connecting device. For example, as the optical input / output device, a semiconductor laser array (surface emitting laser), L
An ED array, an optical detector array, an optical switch array having a light receiving part or a light emitting part, a spatial light modulation device, an optical fiber array, an optical coupling part of an optical waveguide, and the like. Further, as the light conversion device, any kind of device can be used as long as it has a surface for converting the intensity, phase, wavefront shape, propagation direction, polarization, etc. of light rays incident on a surface or one-dimensional or two-dimensional optical information. It may be one.

Now, the diffractive optical elements 181, 182 and 183 used in the image forming system of FIG. 2 will be described. Each of the diffractive optical elements is a transmissive type and is composed of diffraction gratings arranged in a matrix. In the diffraction grating, for example, as shown in FIG. 3, step gratings 24 are formed in parallel. When the grating pitch is p, the diffraction angle θ is sin θ
= Λ / p However, λ is the wavelength of the incident light. The smaller the grating pitch p, the larger the diffraction angle. Further, in the illustrated diffraction grating, the optical path length of the stepped grating surface is set to 4 steps of 0, λ / 4, λ / 2, and 3λ / 4, but if the steps are finer, the diffraction efficiency can be improved. You can

FIG. 4 shows an example of the grating direction and grating pitch of each diffraction grating array of the diffractive optical element 182 arranged on the Fourier transform plane, and the shift amount of light in each (X, Y) direction by each diffraction grating. Show. The diffractive optical element 182 is for determining the shift amount of light, and it is not necessary for each diffraction grating to have a one-to-one correspondence with each element of the light emitting element array.

FIG. 4A shows a diffractive optical element 182 in which substantially circular diffraction gratings 26 are arranged in an (X, Y) matrix. The (X, Y) direction is the arrow direction shown. By selecting the direction and pitch of the staircase grating, the shift amount of light can be determined as shown in FIG. In the illustrated example, in the X direction, -2, -1, 0,
+1, +2 and -2, -1, 0, +1, +2 in Y direction
Can be shifted by the amount of.

Also for the diffractive optical elements 181, 183,
Although it can be configured by the diffraction grating array as described above, the diffractive optical element 181 is emitted from each light emitting element of the light emitting element array 141 in parallel with the optical axis, and the flat plate microlens array 22.
The light transmitted through the corresponding microlens 1 is deflected to be transmitted to the diffraction grating 26 of the diffractive optical element 182 with a desired shift amount. Further, the diffractive optical element 183 deflects the light transmitted through the diffractive optical element 182 so as to be vertically incident on each microlens of the flat plate microlens array 222. The light transmitted through each microlens of the flat plate microlens array 222 becomes parallel light and enters the corresponding light receiving element of the light receiving element array 142.

FIG. 5 is an equivalent optical system of the inverted equal-magnification imaging system of FIG. 2, and shows an example of connection of optical channels in the Y direction when the diffractive optical element of FIG. 4 is used as the diffractive optical element 182. . When the light channels in the Y direction of the light emitting element array 141 are 1, 2, 3, and 4 from the top, the diffractive optical element 181,
If 182 and 183 are not provided, the light channels 4, 3, 2, and 1 are incident on the light receiving element array 142 in this order from above.

In the example of the optical connection shown in FIG. 5, the light of the channels 1 and 3 includes the flat plate microlens array 221, the diffractive optical element 181, the prism 201, and the gradient index rod lens 1.
After passing 01, the shift amount of the diffractive optical element 182 in the Y direction is +1.
The light of channels 2 and 4 is incident on the diffraction grating of the diffractive optical element 182 whose shift amount in the Y direction is −1. The light deflected in the Y direction by the diffractive optical element 182 receives the gradient index rod lens 102 and the prism 20.
2, through the diffractive optical element 183, the optical channel 3,
The light enters the flat plate microlens array 222 in the order of 4, 1, 2 and is made parallel to the optical axis of the optical system and then enters the corresponding light receiving element.

Next, another example of the image forming system shown in FIG. 2 will be described.
The image forming system shown in FIG. 2 is provided with the diffractive optical element 182 on the Fourier transform surface between the two gradient index rod lenses 101 and 102. Like the diffractive optical elements 181, 183, they may be formed on the flat plate microlens array substrate 16. FIG. 6 shows the image forming system. In this case, the gradient index rod lens 101
And 102, an optical path changing element including a polarization beam splitter 28 having two 45-degree polarization selective surfaces and a quarter wavelength plate 30 provided on the upper surface is arranged. A reflection type diffractive optical element 184 is formed on the surface of the flat plate microlens array substrate 16 facing the.

In such an image forming system, P-polarized light is emitted from the light emitting element array 141. The polarization beam splitter 28 reflects P-polarized light, the reflected P-polarized light passes through the quarter-wave plate 30 and is reflected and deflected by the diffractive optical element 184, and again passes through the quarter-wave plate 30 to become S-polarized light. Is reflected by the polarization beam splitter 28 and propagates toward the gradient index rod lens 102. Since the three diffractive optical elements 181, 182, 184 are formed on the flat plate microlens array substrate 16 in the image forming system having this structure, there is an advantage that the manufacturing is easier than the structure shown in FIG. Although the diffractive optical element 184 is of a reflective type, a mirror provided with a transmissive diffractive optical element may be used.

Next, a method of manufacturing the optical connecting device according to the present invention will be described. As a typical example, an optical connecting device having the image forming system of FIG. 6 is manufactured.

First, as shown in FIG. 7, one surface of each of the glass substrate 32 and the cover glass substrate 34, which have been polished, is ground by a diamond blade.
For example, the lens array groove 36 having a semicircular or rectangular cross section is formed. A long refractive index distribution type rod lens 38 having a diameter of 4 mm is arranged in the lens arrangement groove, and then two glass substrates 32 and 34 are adhered to each other to bond the refractive index distribution type rod lens 38, the glass substrate 32 and the cover. The glass substrate 34 is integrated.

Next, as shown in FIG. 8 (A), a diamond blade 40 is inserted from the surface side of the cover glass substrate 34 that is integrally bonded, and the portion of the cover glass substrate 34 and the gradient index rod lens 38. Are cut, and a part of the glass substrate 32 is left, so that a plurality of rectangular vertical grooves 42 having a width of 5 mm are formed. At this time, as shown in FIG. 8B, both side surfaces 421 and 422 of the groove 42 and the bottom surface 4 are formed.
Reference numeral 23 denotes a diamond blade 40 having a surface roughness Rmax and having a count such that it is finished to a flat surface of about several μm or less.
Grinding is performed using (ground portion: 401). As a result, the gradient index rod lens 38 is cut to form individual gradient index rod lenses having a length of 4.2 mm. Then, prisms,
Insert and fix the polarization beam splitter. At this time, in order to suppress light scattering, in the end surface of the graded index rod lens slightly roughened by the grinding process, the surfaces in contact with the vertical grooves of each prism and the polarization beam splitter and the corresponding surfaces of the vertical grooves ( 421, 422, 42 of FIG.
A refractive index matching process of filling a refractive index matching material may be performed between 3).

Finally, by burying the ground and removed portion of the cover glass substrate with glass, reliability against mechanical vibration, contamination of dust and the like is secured. The light propagation substrate 12 is manufactured as described above. In the above example, a glass substrate was used as the substrate that sandwiches the gradient index rod lens, but any parallel flat substrate that transmits light of the used wavelength may be used, such as an acrylic substrate or a used wavelength. When it is about 1.3 μm or 1.5 μm, it may be a silicon substrate.

According to the above method, since each gradient index rod lens is originally produced by cutting one long gradient index rod lens, perfect coaxial alignment of the optical axis in the imaging system is achieved. You can secure the sex. Therefore, for example, when a positional deviation of the insertion part occurs, the deviation is not amplified even when propagating through the imaging system, and remains the initial deviation.
If the coaxiality of the optical axis is not ensured, if a deviation occurs, the deviation will be amplified as it propagates through the imaging system.

On the other hand, the flat plate microlens array substrate 16
A transmission type diffractive optical element and a reflection type diffractive optical element are manufactured by a photolithography technique on the surface on which the microlens array is formed. The flat microlens array substrate 16 has a diameter of 225 μm and f = 62.
A microlens array having a pitch of 5 μm and a pitch of 250 μm is provided.

Such a flat plate microlens array substrate 16 is aligned and bonded and fixed to the light propagation substrate 12, and the alignment method will be described below.

As shown in FIG. 9A, as a first alignment marker, a portion outside the area of the microlens 44 of the flat plate microlens array 221 on the first conjugate image plane of the telecentric unity-magnification system is used. Four pinholes 46 located at the apexes of the square are provided. On the other hand, FIG.
As shown in (B), four cross patterns 48, which are second alignment markers, are patterned on the flat plate microlens array 222 on the second conjugate image plane at positions corresponding to the pinholes.

The pinhole and the cross pattern as such an alignment marker are produced as follows. On the lens surface side of the flat microlens array,
For example, a light-shielding film made of a Cr film or a Cr / Cr ₂ O ₃ laminated film is provided, which is formed by opening this light-shielding film. Specifically, it is formed by sputter depositing a Cr / Cr ₂ O ₃ film, patterning the lens portion and the alignment marker portion by photolithography, and removing them by etching. Alternatively, when forming the microlens by the ion exchange method, the alignment marker can also be formed as the refractive index distribution region.

When the flat plate microlens array substrate 16 is aligned with the light propagation substrate 12, the pinhole 46 on the first conjugate image plane is irradiated with light. The light passing through the pinhole passes through the non-grating portion of the transmissive diffractive optical element 181 and is reflected by the non-grating portion of the reflective diffractive optical element 184 to pass through the non-grating portion of the transmissive diffractive optical element 183. The light passes through and forms an image on the lens-side surface of the flat plate microlens array 222. By observing the overlapping state of the image 461 of the pinhole 46 and the cross pattern 48 on the second conjugate image plane, the pinhole image 461 is aligned with the center of the cross pattern 48. Such alignment can be performed using an image monitor alignment device. An image 461 of the pinhole is shown in FIG.
10 corresponds to the cross pattern 48, as shown in FIG.
FIG. 6B shows a state in which the pinhole image 461 is displaced from the cross pattern 48. If they match as shown in FIG. 10A, it is assumed that the flat plate microlens array substrate 16 is positioned on the light propagation substrate 12, and the flat plate microlens array substrate 16 is adhesively fixed to the light propagation substrate 12.

FIG. 11 shows an equivalent optical system for explaining the positional deviation between the light propagation substrate and the flat plate microlens array substrate. Diffractive optical elements are omitted for ease of understanding. FIG. 11A shows a state in which the flat plate microlens array substrate and the light propagation substrate are in alignment, and FIG. 11B shows a state in which there is a positional deviation. If there is a positional shift, the light flux will shift at the position of the flat plate microlens array on the light receiving side. When the position shift occurs, problems such as a decrease in light utilization efficiency and occurrence of crosstalk occur.

In the above alignment example, positioning is performed using one telecentric unity-magnification imaging system, but when a two-dimensional pattern of light can be propagated over a plurality of unity-magnification imaging systems. If the pinhole and the cross pattern are aligned with each other at a distance as long as possible, the alignment accuracy is improved.

Further, two of the four pinhole images are aligned with the two cross patterns on the second conjugate image plane,
It is better to align the other two pinholes with the two cross patterns on the third conjugate image plane in the next stage and monitor the second and third conjugate image planes simultaneously with the twin-lens microscope. Alignment accuracy is further improved.

Next, the optoelectronic component 14 is mounted on the flat plate microlens array substrate 16, and the alignment of the optoelectronic component to the flat plate microlens array substrate is performed as follows. That is, as shown in FIG. 12, a plurality of hemispherical etching recesses 52 are formed in the flat plate microlens array substrate 16, while a pair of hemispherical etching recesses 52 are formed on the flat plate microlens array substrate etching groove. A plurality of hemispherical etching concave portions 54 corresponding to 1 are formed. When the optoelectronic component 14 is mounted on the flat microlens array substrate 16, the optoelectronic component 14 is arranged so that the ball lens 56 is sandwiched between the corresponding etching recesses 52 and 54. Thus, the alignment of the optoelectronic component with respect to the flat plate microlens array substrate can be performed by a mechanical method. After the alignment, as shown in FIG. 13, the flat microlens array substrate and the solder pads 60 and 62 provided on the optoelectronic component are soldered to be mounted.
A wiring pattern 64 is patterned on the surface of the flat plate microlens array substrate 16 on the electronic component side in order to input a signal to the electronic component.

The alignment of the optoelectronic component with the flat plate microlens array substrate is performed by a mechanical method using an etching groove and a ball lens. However, such mechanical alignment has a limit in accuracy. Therefore, it is required that the tolerance for positional displacement of the optoelectronic component is large.

A method of expanding the permissible width for such positional deviation will be described. In the case of the telecentric inverted equal-magnification conjugate imaging system as shown in FIGS. 2 and 6, the light flux is directed in the same direction on the flat microlens array substrate on the first conjugate image plane and the second conjugate image plane. It shifts. Therefore, as shown in FIG. 14, when the light propagating substrate is the light propagating substrate 12 shown in FIGS. 2 and 6, the flat microlens array substrate 68 serves as a microlens having coaxial one-to-one correspondence on both sides. If a flat microlens array substrate having the arrays 701 and 702 and having a thickness corresponding to the focal length of the microlens is used, the alignment of the optoelectronic component becomes easy.

FIG. 15A shows a light beam when the position of the light emitting element of the light emitting element array 141 is shifted by Δ to the left in the figure with respect to the optical axis of the microlens. Even if the light enters by deviating from the optical axis of the microlens 701 by Δ, the chief ray advances to the center of the corresponding microlens 702 by the microlens 701 and the microlens 7
The light beam 02 is emitted as a parallel light beam inclined with respect to the optical axis of the microlens.

On the second conjugate image plane, as shown in FIG. 14B, the light transmitted through the microlenses 701 and 702 is deviated by Δ to the left in the figure with respect to the optical axis of the microlenses. Get burned. Since the light receiving element array 142 itself is also shifted to the left by Δ, light enters the light receiving elements of the light receiving element array.

As described above, in the case where the one-stage image forming system is a telecentric inverted equal-magnification conjugate image forming system, by using a flat plate microlens array substrate having flat plate microlens arrays on both sides, In addition, it is possible to widen the allowable range of misalignment when aligning the optoelectronic components, which facilitates alignment.

In the above description of the manufacturing method, the manufacturing method of the optical connecting device having the structure shown in FIG. 6 has been described, but the manufacturing method of the optical connecting device having the structure shown in FIG. 2 can be performed in substantially the same manner. However, the transmission type diffractive optical element 182
Is fixed between the gradient index rod lenses 101 and 102 with both sides sandwiched by spacer glass.

Further, in the above embodiments, the diffractive optical element in which the diffraction grating is formed in a matrix is used. However, in such an optical connection device, the optical connection is uniquely determined and the optical connection is made. It cannot be changed. In the following examples, an optical connection device that solves such a problem will be described.

FIG. 16 shows a liquid crystal spatial light modulator 76 between a flat plate microlens array substrate 72 and a light propagation substrate 74.
FIG. 6 is a cross-sectional view of an optical connecting device that allows writing of a diffraction grating pattern corresponding to a desired deflection angle with a sandwiched therebetween. The light propagation substrate 74 is a gradient index rod lens 1
A polarization beam splitter 78 provided between 01 and 102, which has one polarization selective surface of 45 degrees, and two quarter-wave plates 80 and 82 provided on the upper and lower surfaces of the polarization beam splitter. , A mirror 84 provided on the lower surface of the quarter-wave plate 82, and an optical path changing element. on the other hand,
A prism 86 is provided on the surface opposite to the gradient index rod lens 101, and the gradient index rod lens 102 is provided.
On the surface opposite to the above, a polarization beam splitter 88 having one 45-degree polarization selective surface, and two quarter-wave plates 90 and 92 provided on the upper and lower surfaces of the polarization beam splitter,
An optical path changing element including a mirror 94 provided on the lower surface of the quarter-wave plate 92 is provided.

On the flat microlens array substrate 72, a light emitting element array 94 is provided corresponding to the prism 86.
A light receiving element array or a light modulation device 96 is mounted corresponding to the polarization beam splitter 88.

FIG. 17 shows an enlarged sectional view of a part of the liquid crystal spatial light modulator 76. Flat microlens array substrate 72
And the upper glass substrate of the light propagation substrate 74, an alkali passivation layer 100, a transparent conductive film 102, a liquid crystal layer 104 such as a ferroelectric liquid crystal, an interference mirror 106, a photoconductor 108, and a transparent conductive film 200 are laminated. There is.

In the above optical connection device, each diffraction grating is patterned by writing a diffraction grating pattern corresponding to a desired deflection angle in the liquid crystal layer 104 using writing light having a different wavelength from the signal light. It can be changed and the optical connection pattern is variable. The writing light and the signal light are interfering mirror 1
Separation with 06. The area of the liquid crystal layer 104 is shown in FIG.
It may be spread over the entire surface of the substrate as shown in, or may be limited to only the necessary portions.

In such an image forming system, P-polarized light is emitted from the light emitting element array 94. The polarization beam splitter 78 reflects P-polarized light, and the reflected P-polarized light passes through the quarter-wave plate 82 and is reflected by the mirror 84, and again passes through the quarter-wave plate 82 to become S-polarized light. The light is reflected by the diffraction grating pattern through the plate 80, is again P-polarized through the quarter-wave plate 80, is reflected by the polarization beam splitter 78, and is propagated in the direction of the polarization beam splitter 88.
The polarization beam splitter 88 reflects the P-polarized light, the reflected P-polarized light passes through the quarter-wave plate 92, is reflected by the mirror 94, and again passes through the quarter-wave plate 92 to become S-polarized light.
Flat plate microlens array substrate 7 through the four-wave plate 90
Incident on 2.

According to the optical connecting device as described above, since the diffraction grating pattern can be written by the write signal, the degree of freedom of optical connection is further increased.

In each of the above embodiments, the telecentric equal-magnification imaging system has been described, but the present invention is not limited to this, and it is apparent that the present invention can be applied to a telecentric enlargement imaging system or reduction imaging system. Is.

In each of the above embodiments, the lens surface of the flat plate microlens array is in a conjugate relationship in the image forming system including the two gradient index rod lenses and the two flat plate microlens arrays. I explained an example,
As shown in FIG. 18, the flat plate microlens array 221
To form a conjugate surface with two gradient index rod lenses 1
If the conjugate plane is formed by 01 and 102 and the plane is formed by the flat plate microlens array 222, the distance between the flat plate microlens arrays 221 and 222 can be made large, and therefore, as in the present invention. It is suitable for a structure in which various optical elements such as a prism, a polarization beam splitter, a quarter-wave plate, and a mirror are arranged between a flat plate microlens array and a gradient index rod lens.

[0053]

As described above, according to the present invention,
Since a diffractive optical element is provided on the optical axis of a telecentric imaging system so that light can be shifted, the order of arrays can be rearranged, one-to-many, or many-to-many. It has become possible to provide an optical connection device that enables to-one) connection and expands the degree of freedom of optical connection.

Furthermore, if a liquid crystal spatial light modulator capable of writing a diffraction grating pattern is used as the diffractive optical element, free optical connection can be realized.

[Brief description of drawings]

FIG. 1 is a schematic view for helping understanding of a configuration of an optical connecting device of the present invention.

FIG. 2 is a diagram showing a one-stage representative image forming system in the optical connecting device of FIG.

FIG. 3 is a sectional view of a diffraction grating.

FIG. 4 shows an example of a grating direction and a grating pitch of each diffraction grating array of the diffractive optical element arranged on the Fourier transform plane,
It is a figure which shows the shift amount of the light to a (X, Y) direction by each diffraction grating.

5 is a diagram showing an equivalent optical system of the inverted equal-magnification imaging system of FIG.

FIG. 6 is a diagram showing another example of an imaging system.

FIG. 7 is a diagram showing a step of forming alignment grooves on one surface of each of a polished glass substrate and a cover glass substrate by grinding using a diamond blade.

FIG. 8 is a diagram showing a step of cutting a gradient index rod lens.

FIG. 9 is a diagram showing an alignment marker provided on a flat plate microlens array.

FIG. 10 is a diagram showing a positional relationship between a pinhole image and a cross pattern.

FIG. 11 is a diagram showing an equivalent optical system for explaining the positional deviation between the light propagation substrate and the flat plate microlens array substrate.

FIG. 12 is a diagram showing a process of mounting an optoelectronic component on a flat plate microlens array substrate.

FIG. 13 is a diagram showing a mounting step of soldering an optoelectronic component on a flat plate microlens array substrate.

FIG. 14 is a diagram showing an imaging system using a substrate having flat plate microlens arrays on both sides.

FIG. 15 is a diagram showing luminous flux on a light emitting side and a light receiving side of a substrate having flat plate microlens arrays on both sides.

FIG. 16 is a cross-sectional view of an optical connecting device in which a liquid crystal spatial light modulator can be used to write a diffraction grating pattern corresponding to a desired deflection angle.

FIG. 17 is an enlarged cross-sectional view of a part of the liquid crystal spatial light modulator.

FIG. 18 is a diagram showing an example of arrangement of a flat plate microlens array and a gradient index rod lens.

[Explanation of symbols]

 10, 101, 102 Refractive index distribution type rod lens 12 Light propagation substrate 14 Optoelectronic component 16 Flat plate microlens array substrate 18, 181, 182, 183, 184 Diffractive optical element 191, 192 Glass substrate 201, 202 Prism 221, 222 Flat plate micro Lens array 24 Step grating 26 Diffraction grating 28,78 Polarizing beam splitter 30, 90,92 Quarter wave plate 32 Glass substrate 34 Cover glass substrate 36 Lens array groove 38 Gradient distribution type rod lens 40 Diamond blade 42 Vertical groove 44 microlens 46 pinhole 48 cross pattern 52, 54 etching recess 56 ball lens 62, 64 solder pad 66 wiring pattern 68 flat plate microlens array substrate 701, 702 microlens array 7 Liquid crystal spatial light modulator

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 21, 1995

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

FIG.

[Fig. 2]

[Figure 4]

[Figure 3]

[Figure 5]

[Figure 6]

[Figure 7]

[Figure 8]

[Figure 9]

[Figure 10]

FIG. 11

[Fig. 12]

[Fig. 13]

FIG. 14

FIG. 15

FIG. 16

FIG. 17

FIG. 18

Claims (16)

[Claims] 1. A telecentric image forming system as one unit, wherein the image forming systems are arranged in at least one or more stages on the same optical axis, and are arranged in parallel in at least one column in a light transmissive flat plate. Provided on the optical axis in the light propagation substrate, and the optical path is changed so that light is directed in a direction perpendicular to the optical axis and toward one surface side of the light propagation substrate. At least two optical path changing elements, a flat plate microlens array substrate provided on the one surface side of the light propagation substrate and having a plurality of flat plate microlens arrays at a position facing the optical path changing element, At least one diffractive optical element provided on the optical axis of the imaging system, and at least two optoelectronic components provided on the conjugate image plane and / or Fourier transform plane on the other surface side of the light propagation substrate. And An optical connecting device comprising: 2. The optical connection device according to claim 1, wherein the imaging system is composed of two gradient index rod lenses, and the diffractive optical element is the two gradient index rod lenses. Between the first transmission type diffractive optical element provided on the Fourier transform surface and the second transmission surface provided on the lens surface side of the two flat plate microlens arrays corresponding to the conjugate image surface of the imaging system. An optical connection device comprising a transmission type diffractive optical element, wherein the optical path changing element is provided on each surface of the two gradient index rod lenses opposite to the Fourier transform surface. 3. The optical connecting device according to claim 2, wherein the first transmission type diffractive optical element determines a shift amount of light in the image forming system, and diffracts a grating pattern corresponding to a desired diffraction angle. An optical connection device comprising a grating array, wherein the second transmission type diffractive optical element is a diffraction grating array having a grating pattern corresponding to a desired diffraction angle in correspondence with the matrix arrangement of the element array of the optoelectronic component. 4. The optical connecting device according to claim 1, wherein the imaging system is composed of two gradient index rod lenses, and the optical path changing element is the two gradient index rod lenses. A first optical path changing element provided between the first and second optical path changing elements, and a second optical path changing element provided on each surface of the two gradient index rod lenses opposite to the surface on which the first optical path changing element is provided. And a reflection type diffractive optical element provided on the surface side of the flat plate microlens array substrate facing the first optical path changing element, and a conjugate of the imaging system. An optical connection device comprising transmission type diffractive optical elements provided on the lens surface sides of two flat plate microlens arrays corresponding to the image plane. 5. The optical connection device according to claim 4, wherein the first optical path changing element is at least a polarization beam splitter and a quarter wavelength plate, and the second optical path changing element is a prism or at least An optical connection device consisting of a polarization beam splitter and a quarter-wave plate. 6. The optical connecting device according to claim 4, wherein the reflective diffractive optical element is replaced with a transmissive diffractive optical element and a mirror. 7. The optical connecting device according to claim 4, wherein the reflective diffractive optical element is a diffraction grating array having a grating pattern corresponding to a desired diffraction angle, which determines a shift amount of light in the imaging system. The optical connecting device, wherein the transmissive diffractive optical element is a diffraction grating array having a grating pattern corresponding to a desired diffraction angle in correspondence with the matrix arrangement of the element array of the optoelectronic component. 8. The optical connecting device according to claim 7, wherein the reflective diffractive optical element and the transmissive diffractive optical element can write a diffraction grating pattern corresponding to a desired diffraction angle by writing light. An optical connection device that is a spatial light modulator. 9. The optical connecting device according to claim 1, wherein the optoelectronic component is a light emitting element array, a light receiving element array,
Optical fiber array, optical input / output device for optical waveguide, spatial modulation device or optical connection device which is diffractive optical device. 10. The first and second light-transmissive flat substrates,
A step of forming a groove by grinding or etching using a diamond blade, and a cylindrical long rod lens having a refractive index distribution in the radial direction is arranged in the groove to form first and second light-transmitting planes. Integrating and fixing between the substrates, the first light-transmissive flat substrate and the rod lens are subjected to a grinding process using a diamond blade, leaving a part of the second light-transmissive flat substrate, Dividing into a gradient index rod lens by cutting in the direction perpendicular to the axis of the rod lens, and a gap between the gradient index rod lens and the gradient index rod lens formed by the division. A step of inserting and fixing the optical path changing element and the first transmission type diffractive optical element into a light propagation substrate, and a flat plate having a plurality of flat plate microlens arrays. A step of manufacturing a second transmission type diffractive optical element on the lens surface side of the flat plate microlens array of the microlens array substrate facing the optical path changing element; and aligning the flat plate microlens array substrate with the light propagation substrate. And a fixing step, and a step of mounting an optoelectronic component on the surface of the flat plate microlens array substrate opposite to the microlenses, the manufacturing method of the optical connecting device. 11. The first and second light-transmissive flat substrates,
A step of forming a groove by grinding or etching using a diamond blade, and a cylindrical long rod lens having a refractive index distribution in the radial direction is arranged in the groove to form first and second light-transmitting planes. A step of integrally integrating and fixing between the substrates, the first light-transmissive flat substrate and the rod lens being ground by a diamond blade to leave a part of the second light-transmissive flat substrate, A step of dividing into a gradient index rod lens by cutting in the direction perpendicular to the axis of the rod lens, and between the gradient index rod lens and the gradient index rod lens formed by the division. The first optical path changing element is inserted and fixed, and the second optical path changing element is inserted and fixed on the side of the gradient index rod lens opposite to the first optical path changing element, so that the optical transmission A step of producing a substrate; a transmission type diffractive optical element on a lens surface side of the flat plate microlens array facing the second optical path changing element of a flat plate microlens array substrate having a plurality of flat plate microlens arrays; A step of producing a reflective diffractive optical element or a transmissive diffractive optical element with a mirror on the lens surface side of the flat plate microlens array facing the first optical path changing element; and aligning the flat plate microlens array substrate with the light propagation substrate. And a step of mounting the optoelectronic component on the surface of the flat plate microlens array substrate opposite to the flat plate microlens array, and manufacturing the optical connecting device. 12. The first and second light-transmissive flat substrates,
A step of forming a groove by grinding or etching using a diamond blade, and a cylindrical long rod lens having a refractive index distribution in the radial direction is arranged in the groove to form first and second light-transmitting planes. A step of integrally integrating and fixing between the substrates, the first light-transmissive flat substrate and the rod lens being ground by a diamond blade to leave a part of the second light-transmissive flat substrate, A step of dividing the rod lens into a gradient index rod lens by cutting in a direction perpendicular to the axis of the rod lens, and a gap between the gradient index rod lens and the gradient index rod lens formed by the division. A step of inserting and fixing an optical path changing element to produce a light propagation substrate, and a step of forming a flat plate microlens array substrate having a plurality of flat plate microlens arrays, A step of manufacturing a liquid crystal spatial light modulation element on the lens surface side facing the optical path changing element; and the flat microlens array substrate is aligned and bonded and fixed to the light propagation substrate with the liquid crystal spatial light modulation element facing. A method of manufacturing an optical connection device, comprising: a step; and a step of mounting a device component on a surface of the flat plate microlens array substrate opposite to the microlenses. 13. The optical connecting device according to claim 10, wherein when the flat plate microlens array substrate is aligned with the light propagation substrate, the first alignment marker and the second alignment marker are: Arranging the flat plate microlens array substrates provided at different positions on the light propagation substrate; and irradiating the first alignment marker with light to form an image of the first marker through the light propagation substrate. , A step of forming an image in the vicinity of the second marker, and a step of aligning the image of the first alignment marker and the second alignment marker with each other. 14. The optical connecting device according to claim 10, wherein when the flat plate microlens array substrate is aligned with the light propagation substrate, a first alignment marker, a second alignment marker and a second alignment marker are provided. The step of arranging the flat plate microlens array substrates provided at different positions with the alignment marker of 3 on the light propagation substrate, and irradiating the first alignment marker with light, Forming a part of the image in the vicinity of the second marker through the light propagation substrate, and forming an image of the other portion of the first marker through the light propagation substrate and then the third marker. Forming an image in the vicinity of the first alignment marker and the second alignment marker;
Aligning the other alignment marker with the image of the other part of the first alignment marker and the third alignment marker.
And a step of aligning the alignment marker with the alignment marker. 15. The method for manufacturing an optical connection device according to claim 13, wherein the alignment marker is formed by etching away a light shielding film provided on a lens surface of the flat plate microlens array. 16. The optical connecting device according to claim 13 or 14, wherein the alignment marker is formed as a refractive index distribution region in the flat plate microlens array.