JPH08278522A - Optical interconnection device between boards - Google Patents

Abstract

PURPOSE: To provide an optical interconnection device between boards for attaining economization by eliminating the need of an electric connector and mechanical alignment and also realizing ultrahigh speed and ultrahigh density optical connection between boards. CONSTITUTION: When a light beam from the laser array 1-5 of respective boards 1-1-a to 1-1-e is emitted in two directions, right and left, by a polarizing beam splitter 1-6 and passes the adjacent polarizing beam splitter, a part of the light beam is received by a photodetector and the rest is allowed to pass. By repeating such actions, the light beam advances in free space perpendicularly to the board and is connected to the desired photodetector 1-4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a board for mounting a board on which electrical parts are mounted in a bookshelf shape, and for connecting a board for connecting a signal of ultra-high speed, ultra-high density, and large capacity by using an optical bus. The present invention relates to an optical interconnection device.

[0002]

2. Description of the Related Art In this type of inter-board optical interconnection device, inter-board connection currently in practical use is
It is based on electrical signals, and its performance is determined by the pin density of electrical connectors and the speed of signals that can be transmitted. The current connector pin density is about 1 pin / mm ² . Current situation 100
About 1 W is required to send an electric signal of several cm at a speed of Mbps, and it is necessary to consider heat dissipation.

When a high-speed signal passes between boards, E
The occurrence of MC noise is a problem. Therefore, when connecting the boards with electrical signals, several hundred Mbps,
The connector density of 1 wire / mm ² is said to be the limit. However, the signal speed and the connector density tend to increase year by year, approaching this limit. In order to overcome this limitation, optical interconnection between boards has attracted attention.

An optical interconnection for connecting a multi-channel laser array and a detector array with a fiber array is currently under development, and will be commercially available at low cost in the future. LED or LD is used as a light source,
It will be marketed at 150 Mbps for several thousand yen per channel.

Also proposed is optical interconnection in which optical signals from a surface emitting laser array oscillating at multiple wavelengths are collectively multiplexed into a thick plastic fiber and received by an optical detector array having a demultiplexing function. However, in the optical interconnection using the fiber, the entrance and the exit to be connected are fixed, and it is impossible to realize the optical bus connection which is important in the inter-board optical connection.

In order to solve this drawback, British Tele
P. Healey et al. of com have proposed inter-board bus connection using D-Fiber (P. Healey, "Chapter 7 Multid
imensional Switching Systems in Photonics in Switc
hing, Vol.II, "Edited by JEMidwinter, Pressed by Ac
See ademic Press (London).

The proposal is shown in FIG. Reference numeral 9-1 is a board, 9-2 is an electric component such as an LSI, 9-3 is an E / O element for converting an electric signal from the electric component into an optical signal, and 9-4 is an optical output connected to a backplane. 9-5 is a D-fiber laid in the backplane. The D-fiber is a fiber obtained by cutting off a part of the cladding and core of an ordinary optical fiber as shown in the lower side of the figure. By contacting this part of the two D-fibers, the light couples. Bus connection is realized using this principle. However, since the loss of the optical fiber in the scraped off part is large,
It has the drawback of having to insert an optical amplifier between the boards.

Hinton et al. Proposed an optical bus connection that uses a two-dimensional optical switch (smart pixel) having an optical detector array, a logic circuit, and an optical modulator array mounted on a board, and performs optical connection in free space between them. (T.Sz
ymanski and HSHinton. "Architecture of a Terabit
Free-space photonic backplane ", The internationalco
nferece on optical computing technical digest, OC
'94, Edinburgh, Scotland, August 22-25, (1944) WD2 / 2
21).

A representative of the two-dimensional optical switch is SEE from Bell Lab.
It is a D element. FIG. 11 is a diagram showing the structure of a backplane using the same. 10-1 is a board, 10-2 is an IC to be mounted, 10-3 is a smart pixel array, 1
0-4 is a light beam array between smart pixels, 10-
Reference numeral 5 is a backplane and 10-6 is an electric connector for connecting the backplane and the board. A light beam connects the surface emitting laser, the detector and the smart pixel array consisting of logic circuits. The optical signal is transmitted while digitally reproducing between the adjacent smart pixels. However, this method requires a two-dimensional smart pixel device that receives light on the back surface and emits light on the front surface, but such a device has not been realized at present. Furthermore, there is a drawback that the signal speed and density are limited by the high-speed electrical connector that connects the optical backplane and the board. In addition, such a backboard has a drawback of high cost.

Further, there has been proposed an inter-board optical bus using an optical fiber and a coupler as shown in FIG. 1
1-1 is a board on which electrical components such as LSI are mounted, 1
1-2 is a multi-pin connector for connecting the electrical output from the board to the backboard, 11-3 is an electrical / optical conversion circuit for converting this electrical signal into light, and an optical signal from the optical bus connection is an electrical signal. Optical / electrical conversion circuit for converting to, 11-
Reference numeral 4 is an optical fiber, and 11-5 is an optical coupler. The optical signals from all the boards are converted into light by the optical coupler and distributed to all the boards by the coupler.
It is converted back into electricity. In this method, since the optical bus is connected by the optical fiber, complicated alignment is not necessary. However, one coupler is required for one electrical signal, and a higher-speed electrical signal can be sent to the connector 11
-2, there is a problem that the connector pin density cannot be increased and a problem of EMC.

It has also been proposed to use a hologram to bend the light by connecting the boards with a light beam in free space. FIG. 13 is a diagram showing this configuration.
-1 is a board, 12-2 is an electrical component such as an LSI, 12
-3 is an E / O element for converting an electric signal from the board into an optical signal, and here, a semiconductor laser with a collimator lens is used. Reference numeral 12-5 is a hologram element that bends the light beam emitted from the semiconductor laser to a desired point, and 12-6 is a backboard that supports the board.
12-7 is an element for receiving this light beam,
8 is a light beam. In this method, an optical connection between the two sheets is possible, but a bus connection is not possible, and since an alignment mechanism is not provided for connecting the light beams, it is impossible to connect a thin beam. it is conceivable that.

[0012]

As described above, in the conventional method, there is a problem that the loss of the fiber in the scraped-off portion is large and an optical amplifier must be inserted between the boards, or the electrical connector is used. There is a problem that the signal speed and density are limited and the cost of the backboard is high, and that one coupler is required for each electric signal and the connector pin density cannot be improved. Further, there is a problem that the bus connection is impossible and the thin beam cannot be connected.

The present invention has been made in view of the above,
It is therefore an object of the present invention to provide an inter-board optical interconnection device that can achieve ultra-high-speed and ultra-high-density inter-board optical connection without requiring electrical connectors and mechanical alignment.

[0014]

In order to achieve the above object, the present invention according to claim 1 is a board-to-board optical system for mounting a board on which an electric circuit is mounted in a bookshelf shape to exchange signals between the boards. An interconnection device, which is a polarization beam splitter, a semiconductor laser array that emits a light beam, an optical detector array that receives an optical signal, an array polarization control element that controls the polarization state of light, and an array that finely adjusts the traveling direction of the light beam. A gist is that a polarization control element is provided for each board, a light beam travels in a free space perpendicular to the board, and light is connected to a desired photodetector.

According to a second aspect of the present invention, there is provided an inter-board optical interconnection device for mounting a board on which an electric circuit is mounted in a bookshelf form and exchanging signals between the boards. A prism mirror that reflects a light beam, a semiconductor laser array that emits a light beam, a photodetector array that receives an optical signal, an array polarization control element that controls the polarization state of light, and an array polarization control element that finely adjusts the traveling direction of the light beam. Is provided for each board, and a mirror or a polarization beam splitter is provided on the lower side or the lateral side of the board, and the light beam emitted from the laser array is ± 45 degrees with respect to the board between the polarization beam splitter and the mirror. The point is that the light travels in free space at an angle and is repeatedly reflected to connect the light to the desired photodetector. .

Further, in the present invention according to claim 3, the semiconductor laser array for emitting a light beam is a bundle of optical fibers from a semiconductor laser array for emitting light of multiple wavelengths or a semiconductor laser for emitting light of different wavelengths. The light emitted from the semiconductor laser is converted into one thick beam by one lens, and the boards are connected by wavelength division multiplexing, and a surface type filter array and a surface type detector array or fiber array are provided on the light receiving side. The point is to receive with a photodetector array with.

According to a fourth aspect of the present invention, the element for finely adjusting the direction of the light beam is a liquid crystal element filled in the prism substrate, and the array element for controlling the polarization state is filled in the parallel glass substrate. The gist is that it is a liquid crystal element.

According to the present invention, the polarization state of the light beam is controlled by the liquid crystal polarization control element, and a part of the light beam goes straight on or is reflected by the polarization beam splitter to direct the light to the photodetector. The main point is that the other light beams are made to reach and reflected or go straight on by the polarization beam splitter to allow the light to pass therethrough, thereby enabling the light bus connection.

Further, in the present invention according to claim 6, the λ / 4 plate, the laser array and the detector fiber are mounted on one surface of the polarization beam splitter, and the λ / 4 plate and the prism mirror are mounted on the other surface. And a light beam output from the laser array is emitted in two front and rear directions of the board.
The gist is that the light beam incident from the direction can be received by the detector array.

The present invention according to claim 7 is characterized in that light reflection layers are provided at both ends so that the light beam returns at the terminal end.

[0021]

According to the present invention as set forth in claim 1, the light beams from the laser array of each board are emitted in two left and right directions by the polarization beam splitter, and when passing through the adjacent polarization beam splitter, a part of the light beam is emitted. The light beam travels in the free space perpendicular to the board by repeating the process of receiving it by the detector and passing the rest, and is connected to the desired photodetector.

According to the present invention of claim 2,
The light beam emitted from the laser array travels in free space between the polarization beam splitter and the mirror at an angle of ± 45 degrees with respect to the board, and is repeatedly reflected to be connected to a desired photodetector.

Furthermore, in the present invention according to claim 3,
Light emitted from a semiconductor laser is converted into a thick beam with a single lens, the boards are connected by wavelength multiplexing, and light with a surface type filter array and a surface type detector array or fiber array on the light receiving side. Receive with the detector array.

According to the present invention of claim 4, the direction of the light beam is finely adjusted by the liquid crystal element filled in the prism substrate, and the polarization state is obtained by the array element made of the liquid crystal element filled in the parallel glass substrate. Are in control.

According to the present invention of claim 5,
The polarization state of the light beam is controlled by the liquid crystal polarization control element,
A part of the light beam travels straight or reflects through the polarization beam splitter to reach the photodetector, and the other light beam is reflected or straight by the polarization beam splitter and passes through the light beam. It is possible to connect.

Furthermore, in the present invention according to claim 6,
The light beam output from the laser array is before and after the board 2
The detector array receives the light beams that are emitted in the two directions and are incident from the front and rear directions.

In the present invention according to claim 7, the light beam is returned at the terminal end by the light reflecting layers provided at both ends.

[0028]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a basic configuration of an inter-board optical interconnection device according to a first embodiment of the present invention.
In the figure, reference numerals 1-1-a to 1-1-e are board rows arranged in a bookshelf shape, 1-2 is an electric component such as an LSI mounted thereon, and 1-3 is a prism mirror. , 1-4 is a detector array, 1-5 is a laser array, 1-6 is a polarization beam splitter, 1-7 is the entire backplane on which the board is mounted, and 1-8 is a reflection. Mirrors, 1-9 are light beam buses, and 1-10 are light reflecting layers for returning the light beams that have reached the edge of the optical backboard. Laser array 1
The light beam emitted from -5 is the polarization beam splitter 1
The light travels and reaches the photodetector on the desired board while repeating multiple reflections between the mirror -6 and the mirror 1-9 below the optical backplane 1-7.

FIG. 2 shows the polarization beam splitter 1- of FIG.
6 is an enlarged view of a portion around 6. A flexible cable 2-1 has a function of connecting a laser and a detector to the board. Reference numeral 2-2 is a detector array, 2-3 is a surface emitting laser array, 2-4 is a substrate on which the surface emitting laser array and the detector array are mounted, and 2
-5 is a microlens array, 2-6 is a mirror,
2-7 is a prism mirror, 2-8 is a λ / 4 plate, 2-9 is a polarization beam splitter, 2-10 controls the traveling direction of light, and cross wiring and alignment of light beams are performed. 2-11 is a polarization control liquid crystal element, and 2-12 is a light beam emitted from the surface emitting laser 2-3.

The linearly polarized light emitted from the surface emitting laser 2-3 passes through the λ / 4 plate 2-8 to become circularly polarized light (the thick solid line portion of the arrow in the figure), and is polarized by the polarization beam splitter 2-9. It is separated into a wave (here, a thick broken line with an arrow) and an s-polarized wave (here, a thick hatched part with an arrow). The p-polarized wave goes straight on. On the other hand, the s-polarized light that has been bent 90 degrees by the polarization beam splitter 2-9 passes through the λ / 4 plate 2-8, is reflected by the prism mirror 2-7, passes through the λ / 4 plate 2-8, and becomes p-polarized light. It is converted, and this time, it goes straight through the polarization beam splitter 2-9. For this reason, the linearly polarized light emitted from the surface emitting laser 2-3 is divided into two directions of 45 degrees obliquely downward and emitted.

Next, referring to FIG. 3, the bus of the light beam incident from another board will be described. 3-1 is an incident light beam. The liquid crystal prism 2-10 corrects the incident angle of the light beam incident from the lower right side (the thick broken line portion of the arrow), and is adjusted so as to be incident on the detector 2-2. Next, the polarization controlling liquid crystal element 2-11
To the elliptically polarized light (here, the thick solid line portion of the arrow) controls the polarized light. The polarization beam splitter 2-9 divides it into a component that goes straight (here, a thick broken line portion of an arrow) and a component that reflects at a right angle (a thick shaded portion of an arrow). This 2
By controlling the ratio of two polarization components, the detector 2
It is possible to adjust the component that enters -2 and the component that reflects it as it is. Therefore, if it is not necessary to connect light to this board, it may be reflected entirely. The light beam incident from the lower left reaches the detector 2-2 as well.

As described above, the laser array 2 on the board
The light beam array emitted from -3 is emitted to both sides at an angle of 45 degrees and reaches a desired board while repeating multiple reflection. By controlling the polarization state by the polarization controlling liquid crystal element 2-11, 1: 1 and 1: N interconnections are possible. Moreover, since the liquid crystal prism array 2-10 is mounted, the traveling direction of the light beam can be controlled, the cross wiring of the light can be freely set, and further, the positional deviation caused by inserting and removing the board can be corrected. Is. As described above, it is possible to connect the boards to each other by using the optical beam in the free space.

In this embodiment, since the direction of the thin light beam array from the surface emitting laser 2-3 is controlled by the liquid crystal microprism and connected to the photodetector array 2-2, there is no need for mechanical alignment. . Further, since no fiber is used, no connector is required and the density of the light beam can be increased. Further, although the surface emitting laser is used here, the output from each individual laser may be brought by a fiber array. Further, the detector array 2-2 may be connected not through direct connection with light, but through a fiber array.

4 and 5 are views showing another embodiment 2 of the present invention. FIG. 4 shows a structure in which a polarization beam splitter, a light source, a detector, etc. are mounted on a board, and FIG. 5 shows those optical components mounted in a backboard, and the electrical board and the optical components are mounted on the backboard. This is a structure that is divided. In both figures, 4-1 -a to 4-1
-D is a board row arranged in a bookshelf shape, and
-2 is an electric component such as an LSI mounted on it,
4-3 is a prism mirror, 4-4 is a detector array with a filter, 4-5 is a multi-wavelength surface emitting laser array with a lens, 4-6 is a polarization beam splitter, 4-7 is a board. Is a back plane for mounting, and 4-8 is a reflecting prism mirror. 4-9 is a polarization beam splitter 4-mounted on the board 4-1-b.
A bus of light beams from a laser array 4-5 on
10 is a fine adjustment screw for adjusting the insertion depth of the board.

The light beams emitted from the laser array 4-5 are polarized beam splitters 4-6, similar to the first embodiment.
The light is emitted in two left and right directions by the action of the λ / 4 plate. The light reaching the end of the optical backboard is shifted in position by the prism mirror 4-8, reflected, and returned.

Since the light beam is wavelength-multiplexed into one beam and has a diameter of 1 mm-10 mm, the light emitted from the light source reaches the detector without particularly adjusting the position of the board. If the adjustment is still required, the adjustment screw 4-10 is used to adjust the insertion depth of the board so that the light reaches the photodetector.

Since the polarization controlling liquid crystal element is provided as in the first embodiment, it is possible to control so that the light reaches only the desired board.

FIG. 5 shows a structure in which the electrical mounting portion and the optical interconnection portion are separated. The board plugs into connector 4-12. The optical backboard and this board are connected by connector pins 4-11. Since the optical backboard is not affected by the insertion / removal of the electric board, it is not necessary to calibrate the alignment once the optical part is mounted.

FIG. 5 shows the structure on the light source side. FIG. 5A is a surface emitting laser array with a lens, which emits light at multiple wavelengths.
FIG. 3B is a diagram showing a laser with a fiber that emits light at different wavelengths and a wavelength-multiplexed collimated beam. FIG. 6 shows the configuration of the detector array with a filter array 4-4, and FIG. 7 shows an enlarged view around the polarizing beam splitter 4-6.

FIG. 6A shows an example using a surface emitting laser as a multi-wavelength light source. 5-1 is a surface emitting laser array that emits light with multiple wavelengths, 5-2 is a lens that collimates the light from the surface emitting laser, and 5-3 is a collimated light beam. In order to allow the surface-emission laser array 5-1 to emit light at multiple wavelengths, it is common to provide a heater electrode in each cell and control the temperature of each cell to control the emission wavelength. Alternatively, a method of controlling the emission wavelength by controlling the film thickness of the cavity when manufacturing the surface emitting laser is also effective. For example, a surface emitting laser that emits light at 16 (= 4 × 4) different wavelengths at 1 nm intervals within a 1 mm square surface emitting laser has been reported (for example, L. Fan et a.
l. "8x6 Wavelength-tunable vertical cavity surface
emittingarray, "The technical digest of LEOS'94, SL
5.3, and Koyama et al. "Two-dimensinal multiwavel"
ength surface emitting laser arrays fabricated by
nonplanar MOCVD, "Electronics Lett., vol.30,1994, pp.
1947).

The light beam emitted from the 4 × 4 surface emitting laser within 1 mm square is collimated by the lens 5-2. In the experiment, the light beam had a wide width of 5 mm, and 16 wavelengths of the optical signal were multiplexed and sent in this.

FIG. 6B shows the case where individual lasers with pigtails having different wavelengths are used as the light source. 5-4
Is a semiconductor laser that emits light at different wavelengths, and 5-5 is an optical fiber of the output from the semiconductor laser 5-4. Here, a multimode fiber is used. Reference numeral 5-6 is a bundle of the fibers and their end faces are aligned, 5-7 is a lens, and 5-8 is a collimated light from the optical fiber.

In FIG. 6B, nine different wavelengths are wavelength-multiplexed. A laser 5-4 is arranged in the vicinity where a high-speed electric signal is generated, and the light from the laser 5-4 is bundled by an optical fiber 5-6 and emitted as a thick light beam 5-8 having a diameter of 1-10 mm from the board end. Since the beam diameter is large, it is not necessary to align the light beam. Even with the accuracy of mounting a board by using a normal bookshelf, the optical connection between the laser and the detector is possible without any problem.

FIG. 7 shows the structure of the light receiving side. FIG. 7 (a) shows a detector array with a filter array, and FIG. 7 (b) shows a filter array and a detector group connected by an optical fiber. 6-1 is a filter array, 6-2 is a microlens array, 6-3 is a detector array, 6-4 is a light beam, 6-5 is an individual photodetector group, 6-6 is an optical fiber, 6-7 has shown the front-end | tip part of an optical fiber array. In the figure, these parts are shown separately, but in reality, they are bonded together. The filter array 6-1 may be formed by cutting a thin thin film interference filter into small pieces and adhering them. As shown in FIG. 9, a liquid crystal variable wavelength filter array may be used.

Here, the liquid crystal variable wavelength filter array will be described with reference to FIG. This filter array
It is composed of an upper substrate A, a liquid crystal layer B, and a lower substrate C. The upper substrate A is a microlens array substrate 8-1 with a dielectric mirror 8-3 and a transparent electrode 8-2. Reference numeral 8-5 is a liquid crystal layer, which is homogeneously aligned. The lower substrate C is a glass substrate 8-8 having a dielectric mirror 8-6 and a transparent electrode 8-7 divided for each cell.

A Fabry-Perot interferometer is constituted by opposed dielectric mirrors, liquid crystal is included between them, and a voltage is applied to change the refractive index of the liquid crystal, thereby changing the transmission wavelength. By adjusting the voltage applied to the individual electrodes, the transmission wavelength of each filter in the filter array can be adjusted. Actually, the voltage applied to each cell is adjusted by applying a voltage obtained by dividing the voltage from the power source of about 5 V by the semi-fixed resistor. Since the transmission wavelength pattern of the variable wavelength filter array can be freely set, the optical cross wiring can be freely set. In addition, since the microlens array is used for the upper substrate, the transmitted light is individually collected. The liquid crystal variable wavelength filter has polarization dependence, but in the inter-board interconnection of the present invention, the light incident on the filter array is only linearly polarized light parallel to the liquid crystal. Gender does not matter.

FIG. 8 is a drawing showing details around the polarization beam splitter used in the second embodiment shown in FIGS. 4 and 5, and FIG. 8 (a) shows how light is emitted from the wavelength multiplexing light source. FIG. 8B is a diagram showing how the wavelength-multiplexed light is incident on the detector. 7-1 is a λ / 4 plate, 7-
2 is a polarization controlling liquid crystal plate, 7-3 is a prism mirror, 7-
Reference numeral 4 is a polarization beam splitter. The wavelength-division-multiplexed light beam emitted from the light source passes through the λ / 4 plate 7-1 and becomes circularly polarized light (thick solid line with an arrow), and is polarized by the polarization beam splitter 7-4 (thick broken line with an arrow). Part) and s-polarized wave (thick hatched part of arrow). The p polarized wave goes straight through the polarization beam splitter 7-4, but the s polarized wave is 9
Bend 0 degrees and go to the adjacent board on the left. The p-polarized light that travels straight is a λ / 4 plate 7-1, a prism mirror 7-3, and a λ / 4 plate 7.
The polarized beam splitter 7-
Bend at 4 and go to the adjacent board on the right. On the other hand, the same applies to the light beams incident from the adjacent boards, and the light beams incident from the left and right reach the photodetector. At this time, since the diameter of the light beam is large, no mechanical alignment is required.

In this embodiment, since no fiber is used, no connector is required and the density of the light beam can be increased. Further, since wavelength division multiplexing is performed to form one thick light beam, optical connection can be performed without special beam alignment. In the present embodiment, wavelength multiplexing is used to achieve multiple channels, but as with the first embodiment, a light beam array may be used to achieve multiple channels by space division.

As described above, in the inter-board optical interconnection device of the present embodiment, the free space optical connection is applied to the inter-board optical interconnection, and the light beam emitted from the laser array of each board is left and right by the polarization beam splitter. The light is emitted in two directions, and when passing through the adjacent polarization beam splitter, a part of it is received by the detector and the rest is passed. By repeating this, it is possible to realize the optical interconnection between the polarization beam splitters provided at the ends of the boards by utilizing the advantages of the conventional board mounting and the advantages of the optical interconnection. In addition, in order to accurately align the light beam, a polarizing element that controls the direction of the light beam is provided, and as another method, wavelength-multiplexed and connected as a thick beam so that accurate alignment is not necessary. There is.

[0051]

As described above, according to the present invention,
In a board-to-board interconnection device that mounts electrical boards on a bookshelf and exchanges signals between the boards, a polarizing beam splitter, a prism mirror that reflects the light beam, a semiconductor laser array that emits the light beam, and an optical An optical detector array that receives signals,
By providing an array polarization control element that controls the polarization state of light,
Further, by providing a polarization control element array for aligning the light beam, or by making a thick beam by wavelength multiplexing, without providing a special alignment mechanism,
It is possible to connect optical buses between boards.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of an inter-board optical interconnection device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration around a polarization beam splitter used in the inter-board optical interconnection device of FIG.

FIG. 3 is a diagram showing a structure around a polarization beam splitter used in the inter-board optical interconnection device of FIG. 1, and is an explanatory diagram showing a bus of a light beam incident from another board.

FIG. 4 is a diagram showing a configuration of an inter-board optical interconnection device according to another embodiment 2 of the present invention.

5 is a diagram showing a structure in which an optical component is separated from a board on which an electrical component is mounted in the second embodiment shown in FIG.

FIG. 6 is a diagram showing a structure on the light source side in Example 2 of FIGS. 4 and 5;

FIG. 7 is a diagram showing a structure on a light receiving side in Example 2 of FIGS. 4 and 5;

FIG. 8 is a diagram showing a configuration around a polarization beam splitter in Embodiment 2 of FIGS. 4 and 5;

FIG. 9 is a diagram showing a configuration of a liquid crystal variable wavelength fiber array.

FIG. 10 is a diagram showing a configuration of inter-board bus connection using a D-fiber.

FIG. 11 is a diagram showing a structure of a backplane using interconnection between smart pixel boards.

FIG. 12 is a diagram showing a configuration of an inter-board optical bus using an optical fiber and a coupler.

FIG. 13 is a diagram showing interconnection between boards using a hologram.

[Explanation of symbols]

 1-1-a to 1-1-e Board 1-3, 2-7 Prism mirror 1-4, 2-2 Detector array 1-5 Laser array 1-7 Backplane 1-8 Reflection mirror 1-10 Light reflection Layer 2-3 Surface-emitting laser array 2-5 Microlens array 2-6 Mirror 2-8 λ / 4 plate 2-9 Polarizing beam splitter 2-10 Liquid crystal prism array 2-11 Polarization control liquid crystal element

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H04B 10/12 (72) Inventor Shigeki Hino 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph Phone Co., Ltd.

Claims (7)

[Claims] 1. An inter-board optical interconnection device for mounting a board on which an electric circuit is mounted in a bookshelf form and exchanging signals between the boards, which comprises a polarization beam splitter, a semiconductor laser array emitting a light beam, and an optical beam. An optical detector array that receives signals, an array polarization control element that controls the polarization state of light, and an array polarization control element that finely adjusts the traveling direction of the light beam are provided for each board, and the light beam is free to be perpendicular to the board. An inter-board optical interconnection device characterized in that it travels through a space and light is connected to a desired photo detector. 2. A board-to-board optical interconnection device for mounting a board on which an electric circuit is mounted in the form of a bookshelf and exchanging signals between the boards, which comprises a polarization beam splitter, a prism mirror for reflecting a light beam, and an optical beam. A semiconductor laser array that emits a beam, an optical detector array that receives an optical signal, an array polarization control element that controls the polarization state of light, and an array polarization control element that finely adjusts the traveling direction of the light beam are provided for each board. A mirror or a polarizing beam splitter is installed on the lower side or the lateral side, and the light beam emitted from the laser array travels in free space at an angle of ± 45 degrees with respect to the board between the polarizing beam splitter and the mirror, and is reflected. Optical interconnection between boards, characterized in that light is connected to a desired photodetector while repeating Location. 3. The semiconductor laser array that emits a light beam comprises a semiconductor laser array that emits light of multiple wavelengths or a bundle of optical fibers from semiconductor lasers that emit light of different wavelengths, and is emitted from the semiconductor laser. Converted light into a thick beam with one lens, connect the boards with wavelength multiplexing, and receive on the receiving side with a surface filter array and a surface detector array or an optical detector array with a fiber array. The inter-board optical interconnection device according to claim 1 or 2, characterized in that: 4. An element for finely adjusting the direction of a light beam is a liquid crystal element filled in a prism substrate, and an array element for controlling a polarization state is a liquid crystal element filled in a parallel glass substrate. The inter-board optical interconnection device according to any one of claims 1 to 3. 5. A liquid crystal polarization control element controls the polarization state of a light beam so that a part of the light beam goes straight to or is reflected by a polarization beam splitter to allow light to reach a photodetector, and the other light beams are polarized. 4. The inter-board optical interconnection device according to claim 1, wherein the optical bus connection is made possible by allowing the light to pass through as it is reflected or straight by the beam splitter. 6. The one side of the polarization beam splitter comprises:
The λ / 4 plate, the laser array, and the detector fiber are mounted, and the other surface is provided with the λ / 4 plate and the prism mirror, and the light beam output from the laser array is emitted in two front and rear directions of the board. 4. The inter-board optical interconnection device according to claim 1, wherein a light beam incident from a direction can be received by a detector array. 7. The inter-board optical interconnection device according to claim 1, wherein a light reflection layer is provided at both ends so that the light beam returns at the end.