JP2009042848A - Optical parallel arithmetic unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical parallel arithmetic unit for executing a much higher speed analog parallel arithmetic operation by shortening a time to be spent on input/output time as much as possible. <P>SOLUTION: This optical parallel arithmetic unit is configured to store photoresponsive substance 14, and a partition 12 is provided with a photonic crystal 12a formed with a light waveguide path and a resonator inside through which only specific wavelength is selectively transmitted, and a plurality of adjacent optical cells installed in a mirror 15 for reflecting incident excitation rays of light, and for guiding the excitation rays of light to the adjacent optical cells 11 are formed on a bottom part 13. Furthermore, this parallel arithmetic unit is provided with a light source 16 for emitting the rays of light to the optical cells; a filter 17 and a light detector 18, and photoresponsive substance 14 in the plurality of selected optical cells 11 adjacent to the specific optical cell 11 is made to emit the rays of light based on the excitation rays of light from the light source 16, and the photoresponsive substance 14 of the specific optical cell 11 is irradiated with the excitation rays of light, and the photoresponsive substance 14 is made to emit the rays of light. Transmission and processing based on a series of rays of light using this and an electric signal is repeated so that a high speed parallel arithmetic operation can be achieved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical parallel computing device for speeding up analog computation by parallelizing a plurality of analog computations.

  With recent demands for speeding up information processing apparatuses, parallel processing is required. For this reason, a parallel arithmetic device in which a plurality of digital arithmetic processing circuits are incorporated is provided. However, for analog information, parallel digital arithmetic must be performed after each signal is converted into a digital signal. For this reason, in order to speed up the arithmetic processing, an arithmetic device capable of calculating a plurality of analog signals at the same time as an analog signal is required.

  A conventional analog arithmetic element uses a conventional semiconductor element such as an operational amplifier for a single circuit. In a plurality of circuits, an analog signal is first converted into a digital signal, and then a plurality of digital signals are processed. Was. Therefore, in order to perform analog operations of a plurality of analog signals in parallel, the same number of analog-digital conversion circuits as the number of input circuits are required. In addition, as the number of circuits increases, there arises a problem that it becomes difficult to synchronize a plurality of analog-digital conversion circuits.

  On the other hand, an element that performs calculation using light has been proposed. FIG. 10 is a cross-sectional view schematically showing a main part configuration of a conventional optical arithmetic unit. This optical computing element includes a plurality of two-dimensionally arranged optical cells 51, and each optical cell 51 contains a light-responsive substance 54 that responds when receiving light information in a partition composed of a partition 52 and a bottom 53. is doing. Each optical cell 51 is irradiated with light 56 having a predetermined wavelength by the arithmetic light irradiation device 55, and the photoresponsive substance 54 in the optical cell 51 irradiated with the light 56 exhibits photoresponsiveness and detects its state. Thus, the calculation is performed.

  However, such conventional optical arithmetic elements are performed by independent optical cells 51 when performing parallel processing, and information is exchanged between adjacent optical cells 51 during parallel arithmetic. Not done. If computation between adjacent optical cells 51 is necessary, the parallel computation is temporarily stopped, computation between the optical cells 51 is performed, and then the parallel computation is resumed.

  Accordingly, there has been a problem that as the amount of information exchanged between the optical cells 51 increases, the calculation speed of the parallel calculation by the plurality of optical cells 51 decreases. In parallel computation, since processing such as data rearrangement is necessary for pre-processing for performing parallel computation, there is a problem that computation by a single optical cell 51 is faster in some cases.

  In addition, the present inventors recently proposed a parallel analog computing device (FIG. 11) that performs computation at once as image information by expanding a plurality of analog information in two dimensions (Japanese Patent Application No. 2006-257877). This parallel analog computing device processes input, output, and computation in the form of image processing, so that a large amount of analog information can be computed in parallel and quickly.

However, in this technique, analog data of a plurality of circuits is developed into image information at the time of input and converted from image information to analog data at the time of output, so it takes time to process data at the time of input and output. There is room for improvement, and further acceleration of parallel computation is expected.
Matsushige Kazumi, Tanaka Kazuyoshi, “Molecular Nanotechnology”, Chemistry Dojin, p.152-153 (2002) GT Kovacs, NI Maluf and KE Peterson, “Bulk Micromachining of Silicon”, Proceedings of the IEEE, vol.86, No.8, 1536 (1998) F. Bos, Appl. Optics, Vol.20, No.20, 3553 (1981) Laser oscillations in photonic crystals I and II, Kazuo Otaka, Akira Ueda, Kazuaki Sakoda, 54th Annual Meeting of the Physical Society of Japan Yoko Yamaguchi, Mathematical Sciences, 408, Science, p.23 (1997) John D. Joannopoulos, Robert D. Meade, Joshua N. Winn, Translators: Takanori Fujii, Mitsuteru Inoue, “Photonic Crystal”, Corona, p.68-69 Katsumi Yoshino, Hiroyuki Takeda, “Basics and Applications of Photonic Crystals”, Corona, p.64 Yoshihiko Akahane et al. “High-Q photonic nanocavity in a two-dimensional photo crystal”, Nature, 425, 944-947 (2003)

  The present invention has been made to solve such problems of the prior art, and provides an optical parallel arithmetic device capable of performing analog parallel arithmetic at a higher speed by reducing the time required for input / output as much as possible. This is the issue.

  In order to solve the above-mentioned problems, the present invention firstly has a light incident part at the top, and responds when receiving light information in a space partitioned by a partition wall and a bottom part. The upper part of the partition contains a photonic crystal that selectively transmits only light of a specific wavelength, an optical waveguide and an optical resonator are formed inside, and the bottom part reflects light incident from above An optical cell is configured by providing a mirror for guiding to an adjacent optical cell through a lower portion of the partition wall, and an optical cell structure in which a plurality of the optical cells are provided adjacent to each other, and a selected optical A light source that irradiates light to the cell, a filter that transmits light from the light source and reflects light from the photoresponsive substance of the optical cell, and detects light from the photoresponsive substance of the optical cell that is reflected by the filter Equipped with light detector, light source The excitation light causes the photoresponsive substance in a plurality of selected optical cells adjacent to the specific optical cell to emit light, and the light having a specific wavelength selected by the optical resonator inside the photonic crystal of the partition wall is emitted from the emitted light. Light and the excitation light reflected by the mirror are irradiated to the photoresponsive substance of a specific optical cell, the photoresponsive substance is emitted, the emitted light is reflected by a filter, and detected by a photodetector. Sending an operation signal to the light source, irradiating the photoresponsive substance of the optical cell where the detected light is emitted from the light source, and repeating this series of light and electrical signals and processing, high-speed parallel computation An optical parallel computing device is provided.

  Secondly, in the first invention, there is provided an optical parallel arithmetic device characterized in that the photoresponsive substance is a laser dye.

  Thirdly, in the first or second invention, there is provided an optical parallel arithmetic device characterized in that each optical cell has a square shape in plan view and a bottom portion has a quadrangular pyramid shape.

  Fourth, in the first or second invention, there is provided an optical parallel arithmetic device characterized in that the shape of each optical cell is a regular triangular shape in plan view and the shape of the bottom is a triangular pyramid shape. .

  Fifth, in the first or second invention, there is provided an optical parallel arithmetic device characterized in that the shape of each optical cell is a regular hexagonal shape in plan view and the shape of the bottom is a hexagonal pyramid shape. .

  According to the present invention, light from a photoresponsive substance in a plurality of adjacent optical cells emits light of the photoresponsive substance in the target optical cell, the operation of the photodetector and the light source, and the light and the electric signal. When used in combination, the time required for input / output is greatly reduced, it is possible to perform computations only within the device, and an optical parallel computing device for performing parallel computations in higher order can be realized. This greatly contributes to improving the performance of parallel computing devices.

  Hereinafter, the present invention will be described in detail.

  FIG. 1 is a cross-sectional view schematically showing a configuration of an optical parallel arithmetic device according to the present invention, and FIG. 2 is an explanatory diagram of the principle of the optical parallel arithmetic device. Here, a configuration in which three optical cells are provided is shown, but this is merely an example, and in practice, a required number of optical cells can be two-dimensionally arranged.

  The optical cell 11 has a space partitioned by a partition wall 12 and a bottom portion 13 processed by a micromachine technique or the like, and a photoresponsive substance 14 that responds when receiving light information is accommodated in the space. Yes. The partition wall 12 is made of a photonic crystal 12a having an optical waveguide 12a1 and an optical resonator 12a2 in which the upper portion selectively transmits light of a specific wavelength, and the lower portion is reflected by a mirror 15. The light transmitting portion 12b transmits the excitation light. Further, the bottom 13 has a triangular cross section, and a mirror 15 is formed at a portion corresponding to the two sides as shown in the figure. The mirror 15 is provided to reflect the excitation light from the adjacent optical cell 11 and the light source 16 and guide the excitation light to the adjacent optical cell 11 through the light transmission part 12 b of the partition wall 12. Although the upper side of the optical cell 11 is described as opening, it is assumed that the photoresponsive substance 14 is sealed in the apparatus. This sealing may be performed by a method of covering with a light transmissive material, or may be encapsulated. You may make it seal with a transparent member. The photoresponsive substance 14 in the optical cell 11 can be irradiated with light from above. Here, the upper side refers to the direction shown in the drawings, and may be in any direction in actual use.

  As the material of the optical cell 11, a material having optical transparency such as quartz, silicon, silicon nitride, transparent alumina, and glass can be used. The upper part of the partition wall 12 is composed of a photonic crystal 12a having an optical waveguide 12a1 and an optical resonator 12a2 therein. For example, a material such as quartz or silicon, which is a basic material of the optical cell 11, can be used for photo The nicked crystal 12a may be used, or a material such as silicon dioxide may be used. The photoresponsive substance 14 can be made of a material that is excited from the ground state to the excited state and receives light information from the light source 16 and then deactivates to the ground state while emitting light. Examples of such materials include Benzoic Acid, 2- [6- (ethyl amino) -3- (ethylimino) -2,7-dimethyl-3H-xanthen-9-yl] -ethyl ester, monohydrochloride (hereinafter Rhodamine 6G). And laser dyes such as 3- (2′-Benzothiazolyl) -7-diethylaminocoumarin (hereinafter abbreviated as Coumarin6) can be preferably used. These dyes are used after being dissolved in a solvent such as methanol, ethanol, dimethyl sulfoxide or the like. This photoresponsive substance 14 exhibits photoresponsiveness by changing the electronic state of the molecule upon irradiation with light. Further, as the material of the mirror 15, for example, a metal film such as gold or aluminum, a dielectric film, or the like can be used. The above is the description of the optical cell structure.

  Here, the optical waveguide 12a1 and the optical resonator 12a2 provided in the photonic crystal constituting the partition 12 will be described. As an example of a photonic crystal, for example, in a structure in which holes are periodically formed in GaAs having a large dielectric constant of 13, the dielectric constant becomes 1 (air) in the holes of this structure, and FIG. 5 (John D. Joannopoulos, Robert D. Meade, Joshua N. Winn, Translated by: Takashi Fujii, Mitsuteru Inoue, “Photonic Crystal”, Corona, p.68-69) Can be mentioned. Such a structure is called a photonic crystal, and a region called a band gap of light that cannot transmit light is generated in the structure. Moreover, the value of the band gap of light, that is, the wavelength of light that cannot be transmitted, corresponds to the interval between holes in the photonic crystal. If this structure is maintained, it becomes only a reflection wall for light, but by changing a part of the structure in the periodic structure, an optical waveguide (Fig. 6: Katsumi Yoshino, Hiroyuki Takeda, “Basics of Photonic Crystals” And applications “Corona, p.64” and optical resonators (Figure 7: Yoshihiko Akahane et al. “High-Q photonic nanocavity in a two-dimensional photo crystal”, Nature, 425, 944-947 (2003)). Can be formed. As shown in FIG. 6, if the optical waveguide is left without a hole corresponding to the path of light, that portion becomes a light waveguide. Further, if a part of the structure of the photonic crystal is left at both ends as shown in FIG. 7, light resonance occurs in a portion having no periodicity. The resonance wavelength (resonance frequency) of light is reflected in the size and structure of the non-periodic portion as shown in the graph of FIG.

  A photonic crystal is schematically shown in FIG.

  FIG. 9 is a plan view schematically showing a photonic crystal constituting a partition wall of an optical parallel arithmetic element according to an embodiment of the present invention, and a cross-sectional view schematically showing a configuration of an optical cell.

  In the present invention, a light source 16 for irradiating light to the photoresponsive substance 14 of the selected optical cell 11 is provided. For example, a GaN semiconductor laser array can be used as the light source 16. Further, the excitation light from the light source 16 is transmitted between the light source 16 and the optical cell structure and between the light source 16 and the photodetector 18, but from the photoresponsive substance 14 of the optical cell 11. A filter 17 that reflects light is provided. As this filter 17, a known bandpass filter can be used. An operation signal is transmitted to the light source 16 based on the result detected by the light detector 18.

  The calculation operation will be described with reference to FIGS. 1 and 2. First, as shown in FIG. 2, excitation light having a certain wavelength is simultaneously applied to the photoresponsive substance 14 put in the optical cells A and C (11) from the light source 16. Irradiate. At this time, a part of the light incident on the optical cells A and C (11) is reflected by the mirror 15 and applied to the adjacent specific optical cell B (11) via the light transmission part 12b of the partition wall 12. At the same time, these excitation lights once excite the photoresponsive substance 14 in the optical cells A and C (11). Thereby, the photoresponsive substance 14 in the optical cells A and C (11) is deactivated while emitting light. From these emitted lights, light of a specific wavelength is selected by the photonic crystal 12a provided with the optical waveguide 12a1 and the optical resonator 12a2 of the partition wall 12 and irradiated to the specific optical cell B (11). The photoresponsive substance 14 in the optical cell B (11) that simultaneously receives the light of the specific wavelength and the excitation light causes laser oscillation by stimulated emission by the light of the specific wavelength, and the light is reflected by the filter 17. It is detected by the light detector 18. The light detector 18 that has detected this light sends an operation signal to the light source 16, and the light source 16 irradiates the photoresponsive substance 14 in the optical cell B (11) with excitation light. It should be noted that the light from the specific wavelength and the excitation light from only one optical cell 11 are set so as not to have a light quantity that causes stimulated emission. In this case, laser oscillation is not performed. By repeating these series of operations, optical parallel computation can be performed at high speed. Since this optical parallel calculation results in a calculation according to the light intensity, an analog calculation can be realized.

  Therefore, since these operations do not require an external computer, high-speed analog parallel computation becomes possible.

  Next, the present invention will be described in more detail with reference to examples.

  FIG. 3 is a diagram schematically showing the configuration of an optical parallel arithmetic device according to an embodiment of the present invention, and FIG. 4 is a diagram for explaining the principle of the optical parallel arithmetic device. The optical parallel computing device of FIG. 3 has nine optical cells 21, but this is merely an example, and in practice, a required number of optical cells can be two-dimensionally arranged.

  The optical cell 21 has a base made of silicon, has a space partitioned by a partition wall 22 and a bottom 23 processed by semiconductor microfabrication, and methanol of Rhodamine 6G (24) that responds when receiving light information in the space. The solution was contained. The partition wall 22 is made of silicon dioxide, and the upper portion has holes formed at intervals of 278 nm so as to selectively transmit light having a wavelength of 556 nm, the portion of the optical waveguide 22a1 is left without being formed, and the optical waveguide A photonic crystal 22a having an optical waveguide 22a1 and an optical resonator 22a2 therein was obtained by opening holes on both sides of 22a1 and providing an optical resonator 22a2. The lower portion is a light transmitting portion 22b that transmits the excitation light reflected by the mirror 25 on which the gold thin film is deposited. The bottom 23 has a triangular cross section, and a mirror 25 made of the gold thin film is formed on the portion corresponding to the two sides as shown in the figure. The mirror 25 reflects the excitation light from the adjacent optical cell 21 and the light source 26, and guides the excitation light to the adjacent optical cell 21 through the light transmission part 22 b of the partition wall 22. A GaN semiconductor laser array that emits excitation light having a wavelength of 308 nm was used as the light source 26, and a band-pass filter that transmits light from the light source 26 and reflected light having a wavelength of 500 nm or less was used as the filter 27. As the photodetector 28, a photodiode array was used, receiving light from Rhodamine 6G (24) of a specific optical cell 21 and sending an operation signal to the light source 26.

  The operation of this optical parallel computing device will be described using FIG. 3 and the principle explanatory diagram of FIG. As shown in FIG. 4, the optical cells A and C (21) were simultaneously irradiated with excitation light having a wavelength of 308 nm from the semiconductor laser array. At this time, a part of the excitation light irradiated to the optical cells A and C (21) was guided to the adjacent optical cell B (21) by the mirror 25 via the light transmission part 22b. At the same time, these remaining excitation lights once excited the Rhodamine 6G (24) in the optical cells A and C (21). As a result, Rhodamine 6G (24) was inactivated while emitting light. From these emitted lights, light of 556 nm was selected by the photonic crystal 22a having the optical waveguide 22a1 and the optical resonator 22a2 inside the partition wall 22 and led to the optical cell B (21). The Rhodamine 6G (24) in the optical cell B (21) that simultaneously receives the 556 nm light and the excitation light with a wavelength of 308 nm causes laser oscillation by stimulated emission by the light with a wavelength of 556 nm. Reflected and detected by the photodiode array 28. Upon receiving this light, the photodiode array 28 sends an operation signal to the semiconductor laser array 26, and the semiconductor laser array 26 irradiates the optical cell B (21) that emitted the light with excitation light. Analog parallel computation was performed by repeating these series of operations. The light from a specific wavelength and the excitation light from only one optical cell 21 is set so as not to generate a light amount that causes stimulated emission, and laser oscillation is not performed. By repeating these series of operations, the optical parallel operation could be performed at high speed. Therefore, since these operations do not require an external computer, high-speed analog parallel computation becomes possible.

  As mentioned above, although this invention has been demonstrated based on embodiment and an Example, this invention is not limited to the said embodiment and Example, A various deformation | transformation and change are possible.

  For example, in the above description, the case where each optical cell has a square shape in plan view and the bottom portion has a quadrangular pyramid shape has been described as an example. However, each optical cell has a regular triangular shape in plan view. These may be arranged finely, assuming that the shape of the bottom is a triangular pyramid, and the shape is a regular hexagon in plan view, the shape of the bottom is a hexagonal pyramid, and these are arranged in a honeycomb shape May be. These can be produced by simply changing the pattern of the lithography mask when micromachine technology is used to form each optical cell.

  In the present invention, the bottom of each optical cell may be flat at the top.

  Since the present invention can add information to adjacent optical cells, the present invention is expected to be used for calculation of diffusion phenomenon, calculation for image processing, and the like.

It is sectional drawing which shows typically the structure of the optical parallel arithmetic unit of this invention. It is principle explanatory drawing of the optical parallel arithmetic unit of this invention. It is a figure which shows typically the structure of the optical parallel arithmetic element which concerns on the Example of this invention. It is principle explanatory drawing of the optical parallel arithmetic element based on the Example of this invention. It is explanatory drawing of a photonic crystal. It is explanatory drawing of the optical waveguide formed in the photonic crystal. It is explanatory drawing of the optical resonator formed in the photonic crystal. It is a schematic diagram of a photonic crystal. FIG. 2 is a plan view schematically showing a photonic crystal constituting a partition wall of an optical parallel arithmetic element according to an embodiment of the present invention, and a cross-sectional view schematically showing a configuration of an optical cell. It is sectional drawing which shows the structure of the conventional optical arithmetic element typically. It is a figure which shows roughly the parallel analog arithmetic unit which the present inventors previously proposed.

Explanation of symbols

11, 21 Optical cell 12, 22 Bulkhead 12a, 22a Photonic crystal 12a1, 22a1 Optical waveguide 12a2, 22a2 Optical resonator 12b, 22b Light transmitting part 13, 23 Bottom part 14, 24 Photoresponsive substance (Rohdamine6G)
15, 25 Mirror 16, 26 Light source 17, 27 Filter 28, 29 Photo detector

Claims (5)

It has a light incident part at the top and contains a light-responsive substance that responds to light information in a space partitioned by the partition and the bottom. The upper part of the partition only has light of a specific wavelength. A photonic crystal that selectively transmits light and an optical waveguide and an optical resonator are formed inside, and light incident from above is reflected at the bottom and guided to an adjacent optical cell through a lower portion of the partition wall And an optical cell structure in which a plurality of optical cells are provided adjacent to each other.
A light source for illuminating the selected optical cell;
A filter that transmits light from the light source and reflects light from the photoresponsive material of the optical cell;
It has a light detector that detects light from the photoresponsive substance of the optical cell reflected by the filter,
Excitation light from a light source causes photoresponsive substances in a plurality of selected optical cells adjacent to a specific optical cell to emit light,
The photoresponsive material of a specific optical cell is irradiated with light of a specific wavelength selected from the emitted light by a photonic crystal equipped with a partition optical waveguide and an optical resonator, and excitation light reflected by a mirror, and the optical response Luminescent substance,
The emitted light is reflected by a filter, detected by a light detector, and an operation signal is sent to the light source.
Light is irradiated from the light source to the photoresponsive substance of the optical cell where the detected light is emitted,
An optical parallel computing device that performs high-speed parallel computation by repeating transmission and processing using a series of light and electrical signals.   The optical parallel arithmetic device according to claim 1, wherein the photoresponsive substance is a laser dye.   3. The optical parallel arithmetic device according to claim 1, wherein each optical cell has a square shape in plan view, and a bottom portion has a quadrangular pyramid shape.   3. The optical parallel arithmetic device according to claim 1, wherein each optical cell has a regular triangular shape in plan view, and a bottom shape has a triangular pyramid shape.   The optical parallel arithmetic device according to claim 1, wherein each optical cell has a regular hexagonal shape in plan view, and a bottom shape has a hexagonal pyramid shape.