JPH0277731A - Optical inverter - Google Patents

Abstract

PURPOSE:To obtain the subject inverter with high response speed by multiplying an input light and a bias light, and making the multiplied light incident to an optical inverter element which is changed nonlinearly the intensity of the light, and then being taken out an inverted exit light. CONSTITUTION:A waveguide type optical inverter element 104 is mounted on a GaAs substrate plate 101. The ZnSe optical inverter element has a characteristic of changing nonlinearly the intensity of the exit light when the intensity of an incident light exceeds a prescribed value. The waveguide is constituted by interposing a ZnS clad layer 102 between a substrate 101 and the inverter element, and the incident light constituted of a signal light and the bias light are multiplied in the incident side of the waveguide, followed by being wave- guided to the optical inverter element. The exiting side of the waveguide is led to a following photodiode. The switching performance of the optical inverter is max. 10musec at the time of using Ar laser beams to the inverter, and the invertor is operated with high speed of about 1,000 times as much as the speed of a computing element used an usual twisted nematic liquid crystal cell.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical inverter of an optical logic operation element used as a component of an optical computer or the like.

[Prior art] In conventional optical logic operations, Kuniharu Takizawa, Hiroshi Kikuchi, Tato Soda,
As described in Masakatsu Okada, Proceedings of the 35th Applied Physics Association Conference 30P-ZF-9 (19, 88), two linearly polarized lights that are perpendicular to each other correspond to the logical values 0 and l. Optical logic arithmetic method was used. In this calculation method, the optical inverter can be easily constructed by using a twisted nematic liquid crystal cell. The calculation speed in this case is about 10 m5ec because it is limited by the response speed of the twisted nematic liquid crystal.

[Problem to be Solved by the Invention 1] However, in the prior art described above, the calculation speed is limited by the response speed of the twisted nematic liquid crystal;
The problem was that it was much slower than the calculation speed of electronic circuits. The present invention is intended to solve these problems, and its purpose is to provide an optical inverter with a high response speed.

[Means to solve the problem]

The optical inverter of the present invention has means for combining input light and bias light with signal light, and makes the combined light enter an optical inverter element whose transmitted light intensity changes nonlinearly with the incident light intensity. The device is characterized in that it has a means for extracting the light emitted from the light inverting element.

[Function] FIG. 1 shows the basic configuration of the optical inverter of the present invention. The Zn5e optical inverter element 104 is described in B.G. Kim, Applied Physics Letters (All) 1. Phys, Lett, ), Vol.
, 51. No. 5 as set forth in No. 7 1987
It has the characteristics shown in the figure. The operating principle of the optical inverter shown in FIG. 1 will be explained below using FIG. 5. The intensity of the bias light in FIG. 1 is assumed to be Pl shown in FIG. When no input light enters, the output light intensity becomes PH. Also, (p3
When input light with an intensity of p+) is incident and the intensity of the light that enters the Zn5e optical inverter element becomes P3, the output light intensity becomes P2. If you set a light intensity threshold between PH and P, and assign light with an intensity below the threshold to signal 0, and light with an intensity above the threshold to signal 1, the above operation will be performed by the inverter itself. be.

[Embodiment 11] FIG. 1 is a schematic diagram of the configuration of a waveguide type optical inverter in an embodiment of the present invention. In this example, a waveguide type optical inverter was fabricated on a GaAs substrate IOI. Since the light emitting element and the light receiving element can also be easily fabricated on a GaAs substrate, these elements and the optical logic operation element using the optical inverter of the present invention can be fabricated on the same substrate, making integration easy. 104 is a Zn5e optical inverter element,
It has a characteristic that the transmitted light intensity changes nonlinearly with respect to the incident light intensity as shown in FIG.

There is a Z layer between the Zn5e optical inverter element and the GaAs substrate.
An nS cladding layer 102 is present to form a waveguide type element. However, a similar operation can also be obtained in an anti-waveguide configuration in which no ZnS cladding layer is present. As an optical inverter element, in addition to Zn5e, II-Vl group compound semiconductors such as CdS, III-Vl group compound semiconductors such as InSb, etc.
-V group compound semiconductors, IV-Vl group compound semiconductors such as GeSe, or materials whose transmitted light amount changes nonlinearly with respect to the incident light intensity, such as superlattices made of these materials, can also be used. Light incident on the optical inverter element and light emitted from the optical inverter element are guided by an optical waveguide constituted by the ZnSSe waveguide layer 103 and the ZnS cladding layer. In the optical waveguide on the input side to the optical inverter element, input light, which is signal light, and bias light are combined and then guided to the optical inverter element. The optical waveguide on the output side of the optical inverter element has the role of guiding the output light from the optical inverter element to the next stage optical logic operation element, photodiode, or the like.

When we investigated the switching characteristics of the optical inverter with the above configuration using Ar laser light with a wavelength of 488 nm, we found that the maximum switching time was JOμsec, which was 1000 times faster than that of a conventional arithmetic unit using twisted nematic liquid crystal cells. It worked about twice as fast.

Logical operation NAND using light and inverter as above
FIG. 2 does not show an example of the configuration of an optical logic operation element that executes. After inputting the input light A and the input light B to the optical inverter of the present invention to obtain an inverted output, the two output lights are combined and a logical operation of OR is performed, resulting in a logical NAND operation as a whole. is obtained. Further, all logical operation elements can be constructed by combining the optical inverter of the present invention and the OR of logical operation by multiplexing.

[Embodiment 2] FIG. 2 is a schematic diagram of the configuration of a spatial light modulation type optical inverter in an embodiment of the present invention. In this case, the Zn5e optical inverter element 302 is formed on a ZnS substrate 301 that transmits signal light. Input light and bias light are half mirror 3
After being multiplexed by 03 and transmitted through the ZnS substrate, it enters the optical inverter element 302. Therefore, it is necessary to make the ZnS substrate surface on the side where the Zn5e optical inverter element is not formed mirror-finished to reduce scattering loss. It is necessary to make the optical inverter element as thin as possible.In such a configuration, the input light can have a two-dimensional spread, and it is possible to perform parallel operations on image information or matrices.In addition, the optical inverter element It is also possible to use a single crystal bulk processed into a thin plate shape.

FIG. 4 shows an example of an optical logic arithmetic unit configured to perform AND of logic operations using the above-mentioned optical inverter. After inputting the input light A and the input light B to the optical inverter of the present invention to obtain an inverted output, the two output lights are combined by a half mirror to perform a logical operation, and then the output light is By obtaining an inverted output using the optical inverter of the invention, a logical AND operation can be obtained as a whole. Also, the optical inverter and half mirror of the present invention can perform logical operations.
By combining R, all logical arithmetic units can be constructed.

〔Effect of the invention〕

As described above, the present invention has the advantage that it is possible to fabricate an optical inverter that operates at a speed approximately 1000 times faster than that which could be obtained with optical logic arithmetic units using conventional twisted nematic liquid crystal cells. Furthermore, by using the optical inverter of the present invention, all optical logic operations can be executed at high speed, and by adopting the configuration described in the second embodiment, it is possible to execute them with high parallelism.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the configuration of a waveguide type optical inverter in an embodiment of the present invention. FIG. 2 is a schematic diagram of the configuration of an optical logic operation element that uses the waveguide type optical inverter of the present invention as a component to perform a logic operation of NAND. FIG. 3 is a schematic diagram of the configuration of a spatial light modulation type optical inverter in an embodiment of the present invention. FIG. 4 is a schematic diagram of the configuration of an optical logic operation unit that uses the spatial light modulation type optical inverter of the present invention as a component to perform AND of logic operations. FIG. 5 is a Z diagram for explaining the principle of the optical inverter of the present invention.
FIG. 3 is a diagram showing the relationship between the incident light intensity and the output light intensity of the N5E optical inverter element. 101...GaAS substrate 102...ZnS cladding layer 103-・ZZnS5e wave path layer 104...Zn5e optical inverter element 301...
ZnS substrate 302...Zn5e optical inverter element 303...Half mirror and above 2 Applicants: Seiko Epson Co., Ltd. Agent Patent attorney: Masa Homare Kamiyanagi (and 1 other person) Muka Hikari 10112, 0υA/, 1 plate 1o2...・Z Ki S Kuradzu ← Pa row 10φ...ZhSc coming Sunha''-seed output light. Qin Shita...
Half mirror inbite 9 A ri 1,;n RP3

Claims (1)

[Claims] It has means for multiplexing input light, which is signal light, and bias light, and means for inputting the multiplexed light into an optical inverter element whose transmitted light intensity changes non-linearly with the incident light intensity,
An optical inverter comprising means for extracting light emitted from the optical inverter element.