NO310217B1 - Optical logic element and optical logic device - Google Patents

Description

The invention relates to an optical logic element, in particular a multi-state, multistable optical logic element and even more particularly a proximity addressable optical logic element to which addressing takes place without the use of active or passive optical elements, comprising an optical memory material, where the memory material under the influence of an applied magnetic , electromagnetic or electric fields or applied energy can pass from one physical or chemical state to another physical or chemical state, where a physical or chemical state is assigned a specific logical value, and where a change in the physical or chemical state of the logical element causes a change in the logical value and is carried out by the logical element being accessed and addressed magnetically, electromagnetically, electrically or optically for writing, reading, storing, erasing and switching of an assigned logical value. The invention also relates to an optical logic device, in particular for storing data or performing logical and arithmetic operations, where the device comprises a number of optical logic elements, where the optical logic elements are in particular multi-state, multistable optical logic elements, and even more particularly proximity addressable optical logical elements to which addressing takes place without the use of active or passive optical elements, including an optical memory material, where the memory material under the influence of an applied magnetic, electromagnetic or electric field or applied energy can change from one physical or chemical state to another physical or chemical state, where a physical or chemical state is assigned a specific logical value, and where a change in the physical or chemical state of the logical element causes a change in the logical value and is carried out by the logical element being accessed and addressed magnetically, electromagnetically,electrical or optical for writing, reading, storing, erasing and switching an assigned logical value.

The invention generally relates to a new class of optoelectronic devices which can store information and/or perform logical functions by means of an optical memory material which is contained in individually addressable cells or elements. Each element is an independent unit and can be combined with similar elements to form larger assemblies, typically in the form of planar sheets or layers. The latter can be configured for tertiary assemblies, for example by stacking to form optical data memories and optical logic devices with a high ratio between performance and volume.

Current digital optical data storage technologies have been developed in response to an ever-increasing need for data storage capacity in a compact format and have been able to successfully provide solutions that combine a high areal data density with exchangeability and/or portability.

The decisive step has been the use of small, efficient semiconductor lasers that emit coherent light that can be focused to points close to the diffraction limit, so that correspondingly precise definition and close arrangement of the information bits in the data-bearing medium is obtained. In practical systems, cost and space constraints have logically led to a design where the laser beam is scanned over the surface of a rotating disc and records a serial bit stream, while following an optical guide track under servo control.

Systems based on this generic construction solution have now been developed to a point where the data density is close to the theoretical limit, and further development to meet future needs cannot be met by incremental improvements as hitherto.

An obvious limitation is the use of the two-dimensional data storage format. Although the areal data density is high, physical bit positions are limited to a flat surface on a rigid, self-supporting surface with high mechanical quality, resulting in a relatively unimpressive volumetric data density. Recently, technical solutions have been published where data is stored in several levels at different depths below the plate's surface. Discrimination between different layers is possible due to the very small depth of field associated with a precise focus and it is expected that this principle can be developed to include up to ten planes or layers (see e.g. E.K (signature), "Stacking the decks for optical data storage", Optics and Photonics News, August 1994, p.39). It seems, however, that the advantages that can be achieved with the use of multiple layers or plans are partially neutralized by both cost factors and technical compromises between, on the one hand, the number of layers and, on the other hand, the achievable areal data density in each layer. Even implemented according to recently claimed benefits, such technological solutions lack the potential for sustained long-term development and improvement.

In many cases, restrictions on access time and

data transfer rates a much more serious drawback for rotating disk systems than the above-mentioned limitations of data densities and capacities.

In applications where files on a disk must be accessed quickly in a random sequence, the laser focusing servo must quickly move an optical assembly radially from one position on the disk to another. In the correct radial position, tracking must be quickly resumed, which involves adjusting in two dimensions, adjusting the rotational speed, achieving synchronization, and finding and identifying the file title. These electromechanical procedures entail access times that are long, typically 200 ms or more. Measures have been taken to reduce the access time, e.g. by increasing the plate rotation speed to reduce the time required for rotation adjustment and to reduce the weight of the servo-controlled components for focusing and tracking. Improvement in one area, however, entails limitations in another. Increasing the rotational speed enhances the so-called "slow saw effect", i.e. the rapid acceleration and deceleration of the rotational speed necessary to maintain a constant scanning speed of the beam across the surface of the plate when switching between tracks of different radii. This is a dominant cause of latency in data retrieval systems based on optical discs. Attempts to eliminate the sawing effect by using constant rotation speed regardless of radial position lead to a reduction in the areal data density or increasing technical complexity.

It is not surprising that such precision electromechanical optical systems will be slow on timescales typical of the purely electronic domain (microseconds or less), so that optical disk devices cannot be used as direct fast access memories in a wide variety of applications, such as direct random access memory (DRAM) for computers etc. A considerable effort has been made to eliminate the Achilles heel of such devices, namely the need to focus and track without mechanical inertia. Solutions that have been investigated include optoelectronic deflectors, waveguides and diffractive optical elements. Technically and economically viable systems of this kind have not yet been demonstrated in practice and seem to lie several years into the future. In addition, the waiting time problem associated with plate rotation is not solved with such measures.

In rotating disk systems, the data bits are read successively as the laser beam scans along the table, and the data transfer rate is explicitly dependent on the speed of rotation and the linear data density along the track. In a number of applications, such as interactive multimedia, the transfer rate is a significant bottleneck with today's optical disc systems. Given the near-optimal encoding and focusing of data typical of today's developed disc technology, there seems to be little scope for increasing the data transfer rate. One possibility is to increase the rotation speed. This has been done in a number of commercial systems to the point where costs and power consumption now lead to a rapidly diminishing return on further speed increases. Another strategy is to use multiple laser beams that address separate but parallel tracks on the disc. As the number of parallel tracks increases, however, the complexity and cost increase very quickly, and such schemes seem at best to be able to provide speed improvements that fall far short of the expected future needs.

The above disadvantages have been clearly recognized for a long time, and other schemes have been proposed and experimentally investigated, especially page-oriented memory and logic systems, based on holographic technology. In addition to offering the promise of high-density volumetric data storage in three dimensions, holographic systems can be addressed in a paging mode and thus offer the advantages inherent in parallelism, such as high transfer rates. Fast random access of data using inertia-free optoelectronic means is under investigation. Furthermore, logical operations such as high-speed parallel processing for object recognition have been investigated. It has been predicted that holographic memories can be repeatedly erased and rewritten, store gigabyte to terabyte-level data in a volume comparable to a sugar cube, and provide random access times in the microsecond to nanosecond range and data transfer rates of several hundred Mbytes/s ( see eg D. Psaltis and F. Mok, "Holographic memories", Scientific American, November 1995, pp. 52-58). Similar potential performances have been indicated for other systems based on confocal and multi-laser (non-linear) addressing principles (see eg "The optical sugar cube", Photonics Spectra, September 1994, p. 50).

Further, as an example of a page-based optical data storage system, International Published Patent Application No. W096/21228 (Birge) entitled "Branched photocycle optical memory device" which discloses a volumetric optical memory that stores high-density information in three dimensions by selectively activate a photochemical branch reaction from a short-lived thermal intermediate state in the primary photocycle in a light-sensitive protein-based storage medium. In this connection, a so-called "side switching" laser is used which activates a flat layer or a side of the data storage medium on one wavelength and data lasers which on another wavelength send selected data beams that are orthogonal to the selected layer or side. However, this technology is not easy to implement in practical data storage devices and has some significant weaknesses. In order to achieve high volumetric data density, the page switching light must be very intense and uniform within a very narrowly defined spatial area and with a sharp intensity limit. This involves the use of a laser beam and relatively complicated optics to shape the beam. Secondly, a very precisely controlled lighting sequence is required, which includes the use of three separate wavelengths. The optimal timing of the sequences is temperature dependent. Third, the write and read speeds are limited by the time constants of the photocycle, leading to access times in the ms range. Fourthly, reading the stored data will reduce the contrast of these on optical memory media, so that refreshing will be necessary after a certain number, for example 1000 reading operations.

From SE patent no. 501 106 (Toth) entitled "Optical memory" an optical memory of the "Write-Once-Read-Many-Times" type (WORM type) containing a storage element with stable optical states is known. The storage element is divided into a number of memory positions, as the optical state in a given memory position can both be changed and read out using a light beam directed towards the memory position. The memory can be realized completely without moving mechanical parts and have a very short addressing time and enables a particularly high storage capacity. This memory also enables parallel writing and reading of multi-bit words. The storage medium itself can be arranged in several layers or levels. The light beam is then focused to a given memory position, and with the use of eight levels it becomes possible to store a byte in each memory position or x,y position. In an embodiment with 7 7 storage cells of 1 cm each, 9.8 Gbytes can be stored in eight levels and the writing speed will then be 40 Mbytes/s. Reading takes place in absorption mode, which means that the individual levels must have fixed, different thicknesses so that it will be possible to distinguish between the individual steps in the code sequence. However, this means that the volumetric storage density decreases with an increasing number of levels, and the necessity to focus the light beam to a memory position and to maneuver the light beam in the x, y directions entails cost and technical complications.

Although the technical solutions proposed so far may appear impressive, the stated performances in a future commercial environment must be judged in terms of hardware costs, system complexity and the overall form factor of the devices. Based on the current state of the art as it appears from the available literature, it seems correct to conclude that holographic and other side-oriented systems or multilayer systems will not gain traction in the foreseeable future in markets where the requirement for compactness and low cost is paramount. Even if components and materials became available at acceptable costs, the proposed architectures in reality seem to preclude truly compact solutions.

The purpose of the present invention is therefore to overcome the above-mentioned disadvantages of today's known and proposed technology and to provide an optical logic element that can be used to realize optical memories, optical logic and arithmetic circuits, optical switches and also generally to implement optical data processing equipment with low cost and technical complexity, but with extremely high storage density, short access time and very fast transfer time.

Furthermore, the purpose of the invention is to provide an optical logic element and an optical logic device based on the optical logic element, where the optical logic element and the optical logic device appear as a structurally and functionally integrated unit, the essential functions of the element and the device being mainly all realized in the element or device, including functions such as access, addressing, activation, switching and detection.

Another purpose of the present invention is to be able to realize volumetric data storage in a simple way, so that the storage capacity mainly only depends on the form factor and is inversely proportional to the physical dimensions of the logical element.

The above and other purposes are achieved with an optical logic element which is characterized in that the memory material is arranged in or on a substantially layer-like structure, that an activator that generates a magnetic, electromagnetic or electric field or supplies energy to the memory material is arranged in or adjacent to it mainly layer-like structure and in one with this, and that an optical detector for detection of the memory material's optical response conditioned by the physical or chemical state of the memory material is arranged in or adjacent to the mainly layer-like structure and in one with this, so that the optical logic element constitutes one of the memory material, the activator and the detector consisting of a unified, integrated component, as well as with an optical logic device characterized by the fact that the memory material is arranged in or on a mainly layer-like structure, that an activator that generates a magnetic, electromagnetic or electric field or supplies memory material t energy, is arranged in or adjacent to the essentially layer-like structure and in one with this, that an optical detector for detection of the memory material's optical response conditioned by the physical or chemical state of the memory material is arranged in or adjacent to the essentially layer-like structure and in one with this , so that the optical logic element constitutes a unitary, integrated component consisting of the memory material, the activator and the detector, that the device comprises at least one of two or more optical logic elements forming a structure, and that the optical memory material, the activator and the detector in each logic element in the structure merges into and is continuous with the memory material, the activator and the detector in the surrounding logical elements in the structure, so that the structure forms a planar or curved surface body, as each logical element in the structure has a unique assignment between the memory material and the activator and an assignment between the memory material and the optical dete ctor for unambiguous detection of a physical or chemical state in the memory material, so that each logical element in the structure can be accessed and addressed individually.

In a preferred embodiment in the optical logic element, the memory material is arranged in the form of a first layer, the activator is arranged in the form of a second layer adjacent to the first layer and in one with the first layer, or arranged integrated in the first layer, and the optical detector which detects the state of the memory material, arranged in the form of a third layer adjacent to the first layer and in one with the first layer, so that the optical logic element forms said integrated component, consisting of at least three and two layers respectively.

Furthermore, it is advantageous that the activator is formed by one or more direct or indirect radiation-emitting bodies, the radiation-emitting bodies being arranged on or embedded in the ground mass of the second layer. Advantageously, the radiation emitting body is accessed and addressed electrically. It is also advantageous when the radiation-emitting body is a light-emitting diode, preferably a polymer diode.

In addition, it is also advantageous that the radiation-emitting body is frequency tunable, as the frequency tuning takes place in connection with electrical addressing. Furthermore, it is advantageous that the optical detector is an electrically accessible and addressable optical detector and that for the electrical access and addressing of both activator and detector electrodes and electrical conductors are arranged integrated in the second and third layers. In this connection, it is advantageous that electrodes and electrical conductors are based on an electrically conductive polymer material.

In a preferred embodiment of the optical logic device, in each optical logic element the memory material is arranged in the form of a first layer, the activator is arranged in the form of a second layer adjacent to the first layer and in one with the first layer or arranged integrated in the first layer, and the optical detector which detects the state of the memory material, arranged in the form of a third layer adjacent to the first layer and in one with the first layer, so that the optical logic element forms said integrated component, consisting of at least three and two layers respectively , and that each of the layers merges into and is continuous with the corresponding layers in the surrounding logical elements, so that the structure forms a planar or curved surface body of continuous and mutually adjacent respective layers.

Preferably, each structure in the optical logic device takes the form of a thin flexible film.

In a particularly preferred embodiment of the invention, the optical logic device comprises two or more interconnected structures stacked on top of each other, so that the optical logic device forms one of several structures integrated chip or plate-like component.

In a variant of the optical logic device according to the invention, a structure in its entirety or partially configured as an optical memory is preferred, with each optical logic element in the memory forming a memory element that can be accessed and addressed individually. In another variant of the optical logic device according to the invention, a structure partially configured as optical logic or arithmetic circuits or networks of such circuits is preferred, with each of the optical logic elements in the circuits constituting a switching element that can be accessed and addressed individually. In a third variant of the optical logic device according to the invention, groups of the optical logic elements in a structure are configured respectively as memory registers, logic registers and arithmetic registers, each optical logic element (OLE) in a register and each register can be accessed and are addressed individually, and so that the registers can be collectively configured into an optical data processor. Finally, in the optical logic device, it is preferred that access and addressing of the logic elements takes place over the multiplexed communication lines assigned to the structure.

Further features and advantages of the present invention appear from the other appended claims.

The invention will now be explained in more detail by means of exemplary embodiments and with reference to the accompanying drawing.

Fig. 1a shows an optical logic element according to the present invention,

fig. 1b and 1c show the operation of the optical logic element as a binary logic cell,

fig. Id a field effect transistor for the sake of comparison,

fig. 2 a preferred embodiment of the optical logic element,

fig. 3 another preferred embodiment of the optical logic element,

fig. 4 shows the principle of a memory material in the form of an electron trap material,

fig. 5a-d show the principle of a memory material in the form of a light-sensitive conformationally reactive material, in this case bacteriorhodopsin,

fig. 6, 7 further preferred embodiments of the optical logic element of fig. 1,

fig. 8 a particularly preferred embodiment of the optical logic element of fig. 1,

fig. 9 the spectral properties of light-emitting polymer diodes,

fig. 10 schematically a light-emitting polymer diode,

fig. 11 a first embodiment of an optical logic device according to the invention,

fig. 12 another embodiment of an optical logic device according to the invention,

fig. 13 a variant of the optical logic device in fig. 11,

fig. 14 another variant of the optical logic device in fig. 11,

fig. 15 schematically and unfolds the structure of the optical logic device in fig. 14,

fig. 16 a further embodiment of the optical logic device according to the invention, based on the variant in fig. 14,

fig. 17 schematically shows a scheme for addressing the optical logic device according to the invention,

fig. 18 the sixteen Boolean functions of two binary variables generated with an optical logic device according to the invention, and fig. 19 schematically shows a parallel algorithm for four-bit binary full addition for implementation on the optical logic device according to the invention. Fig. 1a schematically shows a preferred embodiment of the optical logic element according to the present invention. A memory material 1 is arranged in a first layer /], the activator 2 which can generate a magnetic, electromagnetic or electric field or supply the memory material 1 with energy, is arranged in the layer l2 on one side of the layer l\, while the detector 3 is arranged in layer ly on the opposite side of layer l\. The layers l\, l2, h can in their entirety comprise respectively the memory material 1, the activator 2 and the detector 3, but it should also be understood that the layers lx, l2, h can be formed from a base material and that the memory material 1, the activator 2 and the detector respectively 3 is embedded or arranged on this. Fig. 1b symbolically shows the operation of the optical logic element OLE according to the invention when writing, reading Cg detection of a logic state 0. In this case, the memory material 1 is supplied with energy in the form of light at a first wavelength X\, while reading takes place at absorption of light at a different wavelength X2. The detected light indicating the logic state 0 is drawn with a shorter photon symbol to indicate reduced intensity due to absorption. Fig. 1c shows a corresponding schematic diagram of the operation of the optical logic element OLE upon detection of a logic state 1, i.e. that no absorption takes place in the memory material 1 in layer 1\. Fig. Id schematically shows an n-channel power transistor to suggest the analogy between the optical logic element according to the present invention and an electronic switching device. The absorption of the reading light for the logic state 0 and 1 respectively corresponds to the field effect transistor's drain voltage Vd.

Fig. 2 shows an embodiment in which the activator 2 comprises one or more direct or indirect radiation-emitting bodies 2\,..., 2n which are arranged in the layer 12. In fig. 2, the radiation-emitting bodies 2\,... are arranged embedded in a base mass in the layer /2, but they could also be arranged on the layer l2. In a preferred embodiment, the layers l\ and l2 can be combined into a common layer lc. This layer will then include both the memory material 1 and the activator 2 with radiation-emitting bodies 2\, .... This embodiment can be advantageous if the activator is destroyed by writing to the logical element OLE, which may be relevant if it is to be included in a storage device of ROM or WORM type and therefore should not be deleted and/or rewritten.

The optical memory material 1 must be light-sensitive and can exist in two or more distinct physical states, as indicated by fig. lb and lc. These physical states must be able to be determined by the state's response to an incident probe light or reading light. The logic state can be found by applying the activator differently, e.g. according to a specific reading protocol, so that the memory material 1 reacts to the incident light by an optical transmission or emission of light, depending on the logic state.

The basic properties of the optical logic element OLE depend explicitly on the write/read characteristics of the memory material. Changes in the memory material during the writing process can be irreversible, so that an optical logic element is obtained which realizes memory functions of the ROM and WORM type. In the following, however, reference will be made to memory materials which are non-volatile but reversible, i.e. they remain in a formed logical state until they are affected by light for writing, reading or erasing. However, they can be erased, erased and rewritten many times by irradiation with light. Another important property of the memory material is whether it can accommodate multi-level information, i.e. information that is gray-scale coded or whether it responds to a reading protocol of a binary nature, i.e. either with logic state 0 or 1.

Although the memory material 1, as described above, is brought from one physical/chemical state to another by the use of light, this does not preclude that, according to the invention, other forms of energy can be used to influence the state of the memory material. This can involve magnetism, electromagnetism or electronic fields, or through energy being supplied in the form of heat. This can be appropriate if there is a desire to produce dark reactions in process steps between logical states in the memory material, for example the use of heat to erase information, or to produce conditions that make the incident light have an effect, for example the use of an electric field to shift an absorption band if the memory material is a light-sensitive material that absorbs at certain wavelengths.

As can be seen from the above, it will be obvious that the optical logic element according to the invention derives its basic properties from the memory material. In the following, two types of memory material will be described, both of which are reversible, i.e. they can circulate more than once through their logical states by using suitable protocols for writing, reading and erasing.

Electron trap materials are typical organic semiconductor materials doped with rare earth metal ions. Electron trap materials can be used for high density data storage and provide high data transfer and retrieval rates. Reference can be made here to an article by J. Lindmayer, "A new erasable optical memory", Solid State Technology, August 1988.

In general, the operation of an electron trap material is shown in fig. 4. Writing takes place by trapping taking place at the energy levels E and T. When the writing light excites atoms of two rare earth metals used as dopants, their electrons are lifted to the energy level E, which exists in both types of atoms and then trapped at the level T, which only present in one of the atoms. Exposure to light in the near-infrared region at level T lifts the electrons to the communication band, from where they drop to the ground state, resulting in a data smear.

Electron trap materials can have a host lattice in the form of alkaline earth metal sulphide, such as Cas, SrS, MgS or a mixture of these. When the rare earth metals europium and samarium are used as dopants, the memory material absorbs incoming light at 450-550 nm, as the europium ions absorb photon energy and transfer part of this to samarium ions. The latter are thus excited to trap states, named so because these states are stable, i.e. that samarium ions will be stable for very long periods of time unless they are lifted out of the trap due to absorption of suitable energy quanta. The latter will be the case when the memory material is irradiated with light at wavelengths 850-1200 nm, so that the samarium ions in the trap states are stimulated and the freed electrons emit light at wavelengths 600-700 nm when they return to the ground state. Thus, writing takes place in this case by irradiation with light at wavelengths 450-550 nm, while reading takes place by illumination with light at wavelengths 850-1200 nm and simultaneous detection of fluorescence at wavelengths 600-700 nm.

Instead of an electron trap material, the memory material could be a conformationally reactive material and in particular a light-sensitive conformationally reactive material that can undergo a photocycle. Examples of such materials are certain forms of dye proteins. A relatively well-studied protein of this kind is bacteriorhodopsin, which occurs in the membrane of a microorganism, Halobacterium salinarium. For a more detailed discussion of the bacteriorhodopsin's properties with regard to the optical storage of data, reference should be made to NO patent application no. 97 2574 from which the present application, among other things, derives priority and which belongs to the present applicant.

When bacteriorhodopsin absorbs light, it undergoes a photocycle that generates intermediate states with absorption maxima throughout the visible region of the electromagnetic spectrum. Schematically, this is shown in fig. 5a which reproduces the bacteriorhodopsin photocycle and suggests the sequence of structural changes induced by the light. Light-induced transitions or excitation transitions are indicated by shaded arrows, while unshaded arrows indicate transitions due to thermal relaxation. Green light converts bacteriorhodopsin's ground state bR into an intermediate state K which then relaxes to form the M state and then the O state. The residence time in the M state depends, among other things, on both the temperature and the mutant of bacteriorhodopsin used. If the bacteriorhodopsin in the O state is exposed to red light, a so-called branching reaction takes place. The O state transitions to the P state which rapidly relaxes to the Q state, a form of bacteriorhodopsin that has been shown to be stable over a very long time. In various mutants of bacteriorhodopsin utilizing aspartic acid residues 85 and 96, the lifetime of the Q state can be extended to several years. If aspartic acid 85 is replaced by a non-polar amino acid such as aspargine, the formation of a stable M state is prevented and the primary photocycle forms the O state (or an intermediate state very similar to the O state) very quickly (R.R. Birge, Ann. Rev. Phys Chem., 41, pp. 683-733 (1990)). However, if the bacteriorhodopsin in the Q state is irradiated with blue light, it returns to the ground state bR. If the O state is not irradiated with red light, it will relax back to the ground state bR within a short time. Any two long-lived states can now be assigned the binary logic value 0 or 1, and thus it becomes possible to store information in bacteriorhodopsin molecules that are in one or the other of these states.

Fig. 5b is a diagram of the bacteriorhodopsin primary photocycle. The central photochemical transformations which are relevant for use in an optical logic element according to the present invention are indicated on the diagram in a sequence that generally goes around the diagram clockwise. bR denotes the basic state of bacteriorhodopsin, and capital letters indicate the different states in the photocycle. The numbers in frames denote the center wavelengths of the absorption bands for the different states or species of the bacteriorhodopsin in nanometers. Transitions caused by a photoinduced excitation are denoted by hv and possibly by time constants Tv, while transitions due to thermal reactions are denoted by the time constants xp for first-order relaxation times at approximately room temperature.

Illumination of bacteriorhodopsin molecules in the ground or resting state bR with light centered around 570 nm produces the excited state K which has a very short lifetime. As will be seen, the K state has an absorption bandwidth centered at 600 nm, and this implies that if the effective bandwidth upon excitation from the bR state extends beyond 600 nm, molecules in the K state will return to the ground state bR . However, this transition has assumed low quantum efficiency, and as the K state is unstable and very quickly transitions to the L state, most of the molecules in the K state will be driven further in the photocycle, although some molecules will circulate back to the ground state bR. The intermediate state M, which has an absorption band centered at 410 nm, will, during a short time of approx. 1-3 ms relax thermally to the intermediate state N, which in turn relaxes thermally to the intermediate state O. The M state can, as mentioned, in various modifications of the bacteriorhodopsin have a relatively long lifetime, up to several minutes, and could therefore possibly be used to represent a of the logical states 0 or 1 if archival storage over very long periods of time is not required. It may be mentioned here that the M state in reality consists of two states Mj and M2 which have practically identical absorption spectra. It may be added that during earlier attempts at holographic data storage in bacteriorhodopsin using the M state, a gradual loss of sensitivity and contrast was observed, which was later shown to be due to the loss of active molecules by the branch reaction to the P and Q states (R.R. Birge, private communication, 1996). It can be seen from the diagram that the M state returns to the ground state when irradiated with light centered around the M state absorption center wavelength of 410 nm. However, light centered around the absorption center wavelength of the bR ground state, namely 570 nm, will naturally not drive the M state back to the bR state. The O state has an absorption center wavelength of 640 nm and will therefore, if irradiated with light with an effective bandwidth centered around this wavelength, so that a branch reaction occurs in the photocycle, pass to an intermediate state P which has a relatively long lifetime, up to several minutes. The P state will thermally relax to the most stable of the intermediate states of the photocycle, namely the Q state, which has a lifetime that probably extends over several years. The Q state can therefore be used to represent a logical state that is to be retained for years. Next to the stable ground state bR, the Q state is thus the state that is best suited when bacteriorhodopsin constitutes the storage-capable medium in those cases where the optical logic element according to the invention is to be used in an optical data storage device that is suitable for archival storage.

If the Q state is irradiated with blue light with a power bandwidth centered on the Q state's absorption center wavelength of 380 nm, the Q state transitions to the ground state bR, while the time indication ">1" indicates that the Q state will also thermally relax to the ground state bR, but with a time constant which is then many years. The O state also thermally relaxes with a time constant of 4 ms back to the ground state bR. The P state can, upon absorption of light with a power bandwidth centered around the P state absorption center frequency of 490 nm, return to the O state. Incidentally, the 0 state thermally relaxes in the normal photocycle back to the ground state bR with a time constant of approx. 4 ms at room temperature.

To further visualize the bacteriorhodopsin photocycle, this is shown graphically in fig. 5c. The outer circle represents the clockwise progress of the photocycle, from the ground state bR and then through the intermediate states K, L, M, N and O back to the ground state bR. The branch reaction of the photocycle is represented by an inner circular arc with the P and Q states accessed from the O state. Metastable states with relatively long lifetimes, i.e. M, P, and Q are shown shaded. A circle sector represents the area of the photocycle that includes the states Q and bR which for the purposes of the invention are to be considered stable. Photoinduced transitions in the photocycle which are of importance in the present invention are indicated by numbered arrows. - Incidentally, very short-term intermediate states without significance for the invention have been omitted from the diagram. The same applies to cases where an intermediate state is in reality made up of several states with almost identical absorption spectra.

The absorption spectra of the different species or states of the bacteriorhodopsin are shown in fig. 5d which also gives an indication of suitable effect bandwidths when irradiating a species to effect an excitation to another state. It will e.g. can be seen that using a power bandwidth centered around approx. 600 nm will affect the states N, bR, K and O, but the consequence of such irradiation will be that at least a significant proportion of the molecular population will be driven from bR upwards to the relatively stable Q state. The same can of course be achieved by continuously illuminating the bR ground state with a light pulse centered at 570 nm, so that the bR state transitions to the O state, and at the same time also continuously illuminating the bacteriorhodopsin with light centered at 640 nm, possibly after a few milliseconds stay, so that the O state changes to the P state. The implications of this will be discussed in more detail below. From fig. 5d, it will also be seen that the Q state can be effectively excited to the ground state bR by irradiating the molecules in the Q state with light of 380 nm or, for example, an effect bandwidth of 360-400 nm.

The memory material 1 can also be fluorescent, i.e. when it is exposed to the activator 2, the memory material 1 emits fluorescence light which is detected by the detector 3. In other words, the detection takes place in emission. The use of fluorescent materials for data storage is well known to professionals and is also shown in the patent literature, so that a further discussion here will be redundant.

Different preferred embodiments of the optical logic element according to the invention will now be described in more detail.

Fig. 6 shows the optical logic element OLE provided with electrodes 4, 4' or electrical conductors 5, 5' for electrical access and addressing of the activator 2 and the optical detector 3, respectively. The electrodes 4, 4' or the electrical conductors 5, 5 ' is for this purpose arranged integrated in the second and third layers l2 respectively; h- Both electrodes 4, 4' and electrical conductors 5, 5' can preferably be based on an electrically conductive polymer material. If the electrical conductors 5, 5' are arranged in a mutually orthogonal configuration on each side of the layers 1\, /3 respectively, the electrodes 4, 4' can be realized as points of intersection between respective orthogonally arranged electrical conductors 5, 5'. Furthermore, a further layer /4 can be arranged adjacent to the first layer 11 or integrated into it, as shown in fig. 7, for generating an electric field. This can be achieved by the layer /4 being formed of ferroelectric, optoelectric or similar materials, and the generated electric field can then be used to influence the response of the optical memory material 1 in the time domain, the frequency domain or the intensity domain. For example, reference should be made in this connection to the above-mentioned SE patent document no. 501 106, where a photoconductive layer with optoresistive properties is arranged between the memory material and the electrode matrix respectively on one of the memory material's sides. This makes it possible, for example, to selectively apply an electric field to the optical logic element if the activator is a radiation-emitting body, by simultaneously applying an electric control voltage between the layer /4 and an electrode 4.

The radiation-emitting body 2 can be a semiconductor laser, for example formed in the form of a diode laser in layer 12 between electrodes 4, 4'. Optionally, several radiation-emitting bodies 2i,...,2n may be arranged as shown in fig. 2, and they can then be arranged to emit on different pre-selected frequencies, e.g. by the arrangement of diode lasers with specific emission properties.

The radiation-emitting body 2 can also be an indirect radiation-emitting body and it must then be able to be activated by an external radiation source 2' which is not shown in more detail. Such an external radiation source must be arranged outside the optical logic element OLE, and this can, if the optical logic elements are combined into a two-dimensional matrix which constitutes an optical logic device OLD, happen by the radiation emitting body being arranged on the edge of the matrix and outside of this, since the layer l\ must then be able to function as a waveguide that conducts light through the transparent ground mass in the layer l{ and to the indirect radiation-emitting bodies. Such a layer-shaped optical waveguide l2 can be realized in analogy with microstrip lines or fiber optic waveguides and is therefore not to be discussed in more detail here.

However, the desire to obtain a proximity-addressable logic device based on proximity-addressable logic elements makes it generally preferable to use direct radiation-emitting devices 2 arranged in the layer

In that case, the radiation-emitting body 2 can be a light-emitting diode and organic light-emitting diodes based on conjugated polymers are particularly preferred in that connection. Such light-emitting polymer diodes are described in international published patent application no. W095/31515 entitled "Colour source and method for its fabrication" in which the present applicant has acquired rights and to which reference should be made here. Such light-emitting polymer diodes can emit light at several wavelengths by varying the drive voltage of the diodes. The diodes can emit light at different wavelengths, for example mainly red with a low drive voltage and blue with a higher drive voltage, while at intermediate voltages an emission peak can be obtained in both red and blue with varying intensities. The diodes can be produced as a thin polymer film with domains of conjugated polymers and with a thickness of a few tens of nanometers and with an extent of the individual diodes which is in any case not much larger. Integrated as the radiation-emitting body in an optical logic element, they will therefore be compatible with optical logic elements OLE of a corresponding size.

Fig. 8 shows the optical logic element according to the invention realized as a proximity addressable optical logic element. The memory material 1 which, for example, in this case can be a confirmation-reactive, light-sensitive material such as bacteriorhodopsin and forms the layer 1\.

Adjacent to the light-sensitive material 1 or the structure 1, emitters or light sources 2, preferably in the form of light-emitting polymer diodes, are arranged in layer /2. The light-emitting polymer diode 2 is supplied with drive voltage VE across two electrodes 4, 4' which are connected to a current source 6. The light-emitting polymer diode 2 is arranged adjacent to the light-sensitive material 1, i.e. bacteriorhodopsin which is to be driven in a photocycle. This means that the electrode 4' must be transparent. Furthermore, in order to drive the bacteriorhodopsin 1 through the photocycle, the light-emitting diode 2 must provide a wavelength-tunable emission, which means that in the present case it will be relevant to make the light-emitting diode in the form of voltage-tunable polymer diodes of the kind that e.g. is described in the above-mentioned international patent application W095/31515 and discussed in more detail in connection with this reference. Opposite the light-emitting polymer diode 2 and likewise the adjacent bacteriorhodopsin layer /j, there is arranged a photovoltaic or photoconductive detector 3, also as a layer /3, and this is likewise provided with electrodes 4, 4' which lead it from the detector upon detection of light emitted signal voltage VD to an operational amplifier 7, not shown. Obviously, the detector electrode 4 facing the bacteriorhodopsin layer 1 must also be transparent here.

The voltage-tunable colored light sources in the form of light-emitting polymer diodes have, as mentioned, already been discussed with reference to the above-mentioned international patent application W095/31515 and are also described in more detail by M. Berggren & al., Nature 372, pp. 444-446 (1994). By varying the drive voltage Ve applied across the electrodes, such light-emitting polymer diodes will emit light at different wavelengths. The concepts shown for light-emitting polymer diodes of this kind are relatively general, and the spectral characteristics of the emitted light radiation can be controlled within wide limits by appropriate selection of the light-emitting materials. In view of the present description, where it is desirable to have a spectral adaptation to the light-absorbing properties of the bacteriorhodopsin in the different states, it shall be assumed that the light-emitting polymer diode emits yellow light at low voltage VE and with an increasing emission of blue light as the voltage increases. This is shown in more detail in fig. 9a-c, where fig. 9a shows the spectral characteristic and intensity at an applied voltage Ve of 5 volts. The emission mainly takes place in the form of red light with a spectral peak of approx. 630 nm. The utility factor here is 100%. In fig. 9b, the voltage is increased to 16 volts and the efficiency is reduced to 50%. It will be seen that the light-emitting polymer diode still retains the emission peak of approx. 630 nm, but at the same time gets an increasing emission of blue light of approx. 400 nm. At an applied voltage of 21 volts with an efficiency factor of 20%, the emission at wavelengths above approx. 530 nm greatly reduced, and there is mainly an emission peak of blue light with high intensity and centered at approx. 430 nm, as shown in fig. 9c. The voltage-controlled emitter, i.e. the light-emitting polymer diode as described in the above-mentioned international patent application W095/31515, contains a number of physically separated light-emitting domains 9, 9', as shown both in fig. 8 and in fig. 10, which can be regarded as a schematic section through the emitter layer /2. The domains 9, 9' are embedded in a transparent matrix 8 which can for example itself be a polymer, and each domain 9, 9' contains only one type of light-emitting polymer, i.e. either with a narrow band gap that emits mainly in yellow or red (for example 9) or with a wide bandgap that emits in blue (for example 9'). If the domains 9, 9' were large and located at a relatively large distance from each other, this could cause problems due to unpredictable and uneven light emission from the light-emitting diode and with certain optical beam geometries give a poor spatial overlap between respectively red and blue light that hits a given middle site in the bacteriorhodopsin structure. Experimental investigations, cf. the above-mentioned W095/31515, have shown that it is currently at least possible to achieve typical dimensions and distances between the domains in a range from a few 10-nm and up to a few 100-nm, so that the scale factor for the polymer layer's or the thickness of the base material 8 corresponds to the domain cross-section, as the domains must contact the electrodes 4, 4' on the surfaces of the base material. Effects due to spatially discretized light emission will therefore only be noticeable with very small light-emitting polymer diodes, typically on a scale of a few nanometres. On the other hand, there are also indications that the size of the light-emitting polymer diodes 2 can be reduced considerably by reducing the extent of the domains 9, 9', so that any unfavorable spatial effects are avoided even with an extent of the light-emitting diodes of approx. 10 nm or so. The thickness of the emitter layer l2 will then be comparable, and it follows that, at least in theory, it will be possible to realize optical logic elements according to the present invention with an extent of at most a few nm and a corresponding thickness.

The photovoltaic or photoconductive detector 3 is constructed similarly to the emitter 2 or the color light source, namely by using corresponding polymer diodes as shown in fig. 8 and with the domains now as light-absorbing, so that a detected variation in the light intensity spectrally dependent will generate the signal voltage or the detector's output voltage Vd on the electrodes 4, 4'. Likewise, the detector 3 must in this case be matched to the emitter 2's spectral properties. The same scale factors are also obtained for the detector 3 as for the light-emitting polymer diode 2, the dimensions of the domains 9, 9' determining the layer thickness. Obviously, the layer thickness must be compatible with the domain cross-section, so that contacting to the electrodes 5, 5' is achieved.

It will be seen that the optical logic element OLE, which is described with reference to the use of a light-sensitive organic material, namely bacteriorhodopsin and light-emitting polymer diodes, is made proximity-addressable, and the limitations of the scale factors that would exist if the light were led to the light-sensitive organic material are avoided material through optically active structures in the form of refractive or diffractive elements arranged outside the bacteriorhodopsin structure and between this and the emitter. In that case, the size of the optical logic element will be limited by the wavelength of the light radiation used.

An optical logic device OLD according to the invention will now be described with reference to figures 11-17.

Fig. 11 shows an embodiment where the optical logic device is formed in the form of a two-dimensional matrix or structure Sn of optical logic elements OLE and reproduces a section through a row of such optical logic elements, here exemplified by the optical logic elements OLEu and OLE i„ in m n-matrix and with m = n = 5 in this case. Fig. 12 shows an optical logic device according to the invention, where two-dimensional matrices or structures Si,..., Sx of optical logic elements OLE are stacked layer by layer, so that the two-dimensional matrix of optical logic elements constitutes a flat body structure S in a volumetric optical logic device OLD. The optical logic device OLD is thus realized as a three-dimensional matrix, for example with m n x logic elements, where x is the number of stacked structures S. In fig. 12 which schematically shows a section through consecutive stacked rows of the matrices that form the structures S, for example the row m = 1 in the m n matrix, are two optical logic elements OLE in the structure S| designated as OLEM or OLE[n. As shown in Fig. 12, the optical logic device OLD comprises five such structures S, so that x = 5, and fig. 12 can thus be considered to represent a volumetric optical logic device with 5 5 5 = 125 optical logic elements OLE. An optical, thermal or electrically insulating layer /5 is arranged between each of the structures.

In a variant of the optical logic device OLD, groups of optical logic elements OLE, for example in the form of rows, columns or sub-matrices of the m n matrix, can be assigned to a common optical detector 3 which covers all the logic elements in the group, as shown in fig . 13.

As shown in fig. 14, each structure may comprise one or more layers Is which integrally accommodate electrodes 4, 4' and electrical conductors 5.5' assigned to the optical logic elements OLE which are part of the structure S and used for accessing and addressing the optical logic device OLD. As shown in fig. 14, the conductors 5, 5' can be arranged mutually orthogonal, so that the electrodes 4, 4' will in that case be realized at the crossing point between the conductors 5, 5' in each optical logic element OLE, for example so that a diode structure is respectively formed in the layers l2 and h between the crossing point of the conductors 5, 5'.

The arrangement of proximity-addressable optical logic elements in a matrix is shown in perspective in fig. 15, where the individual layers in the matrix, namely the activator layer /2, the memory material layer 1\ and the detector layer /3 which form the optical logic elements OLE, are shown unfolded. The matrix consists of m n logical elements OLE and is shown in fig. 15 in reality shown as a 5 5 matrix. Conductors 5, 5' are arranged on the activator layer 12, cf. fig. 14, and an electrode 4, 4' is obtained at each crossing point between the conductors 5, 5' by applying a voltage to them. If the activator 2 is a light-emitting diode, it will now emit light which affects a memory material in the form of light-sensitive organic material, for example bacteriorhodopsin in layer /j. The detection takes place in the detector layer /2, where by illumination at each crossing point between the arranged conductors 5, 5' in this case a light-absorbing detector diode 3 is correspondingly obtained. The optical logic element which is formed in this way is shown as OLE]3, and each of the layers l1, l2, h or the matrices is in the present case shown as a 5 5 matrix for the sake of simplicity.

The optical logic device shown in fig. 15, can now be used to form a volumetric optical logic device, consisting of structures S in the form of a series of layers or matrices, Si,...,Sx. Such an optical logic device OLD is shown in section in fig. 16, and in each individual layer S an activator layer /2, a memory material layer /] and a detector layer /3 are arranged. As in fig. 15, conductors 5, 5' are arranged, here shown integrated in layer /g, and the optical logic element OLE will have electrodes formed between the crossing points of the conductors 5, 5'. Between each of the structures S and possibly also on the upper side and the lower side of the device OLD, an optically thermal or electrically insulating layer /5 can be arranged. The device as shown in fig. 16, for the sake of simplicity, is suggested to be executed as a cube with 5 5 5 optical logic elements, i.e. 125 in total. The extent of an optical logic element OLEn within the structure Si is shown and may correspond to the optical logic element OLEo as shown in fig. 15.

Since the optical logic elements OLE are proximity addressed, i.e. that both emitter and detector are arranged adjacent to the light-sensitive organic material and are located inside the device, it is only a practical question how many elements an m n matrix can include and how many structures S that can be stacked on top of each other.

In an optical logic device OLD based on the use of

proximity addressable optical logic elements OLE according to it

present invention as shown in fig. 11-12, the only limitation in that scale factor, at least in theory, is the molecular dimensions of the memory material 1, if a light-sensitive conformationally reactive material is used, as well as the realizable smallest extent of the assigned activator 2 and detector 3. When using light-emitting polymer diodes, practical attempt that it is currently possible to realize optical logic elements with an extent of a few tin-nanometers, and correspondingly small conductor structures for the electrodes for emitters and detectors, so that the realistic area of the optical logic element can amount to between 2500 nm and 10,000 nm <2>.1 worst case, this amounts to 10<10> optical logic elements per cm<2> and realized volumetrically with a corresponding layer thickness, in an optical logic device according to the invention it will be possible to achieve 10<15 >proximity addressable optical logic elements in 1 cm<3>. It is considered possible to achieve a linear scale improvement of one order of magnitude, and it will then be possible to realize 10 1 Q optical logic elements according to the present invention in 1 cm<3>. To give an indication of the storage capacity of such an optical logic device realized as an optical memory, it can be suggested that it corresponds to the storage of IO<14> ordinary book pages, which should be sufficient for most types of archival storage.

Fig. 17 schematically shows a scheme for addressing a simple structure S\ in the optical logic device OLD according to the invention. For simplicity, fig. 17 the structure Si in the form of a 5 5 matrix, i.e. with 25 logical elements. For each row and column in the matrix, electrical conductors 5, 5' are arranged in an orthogonal configuration, so that the optical logic element can be accessed and addressed at the intersections between the conductors 5, 5'. With this scheme, it will also be possible to address and activate all optical logic elements OLE. The conductors 5, 5' are connected to respective driver circuits 10, 11 which are connected via an interface 12 to a main bus 13 as shown in fig. 17 is shown in section and carried vertically on the drawing plane, so that it is in connection with all structures S which are part of the optical logic device OLD. Appropriately, the addressing can take place in a hierarchical scheme which can unambiguously address the optical logic device OLD, for example at structure level, or functionally interacting groups of optical logic elements OLE in each structure S or a single optical logic element OLE in the structure S. Those skilled in the art will realize that there are a number of possibilities for realizing access and addressing of a volumetric, optical logic device in proximity, and that parallel access and addressing can also be implemented by using multiplexed communication lines. However, the access and addressing scheme does not form any part of the present invention and is therefore not to be discussed in more detail here.

The optical logic device OLD according to the invention is not only suitable for storing data, but can also be realized as a device for processing data. By processing data in this case it is to be understood that the optical logic elements are combined in optical logic networks to perform logical operations and with the use of optical logic gates and optical logic gate circuits that realize these functions, or in arithmetic circuits to perform binary arithmetic operations realized using arithmetic registers based on binary logic. Groups of logical elements OLE in a structure S will then be able to be configured as memory registers, logical registers and arithmetic registers, as each logical element OLE in a register and each register can be accessed and addressed individually. Collectively, the registers can be configured into an optical data processor. This optical computer technology is analogous to conventional computer technology based on semiconductor components and known to those skilled in the art. In this connection, reference can be made, for example, to Alastair D. McAulay, "Optical Computer Architectures. The Application of Optical Concepts to Next Generation Computers", John Wiley & Sons

(1991), especially "Part II: Subsystems for Optical Computing", pp. 127-342.

The optical logic elements OLE according to the invention can be combined in an optical logic device OLD to be used for data processing into logic circuits which can, for example, perform all possible sixteen Boolean logic functions of two binary variables, regardless of whether an electron trap material is used as memory material or a light-sensitive confirmation-reactive material such as bacteriorhodopsin. A combination of four optical logic elements OLE realizing these sixteen Boolean functions is shown in fig. 18, formed as a 2 2 matrix with logical 0 shaded and logical 1 unshaded. These sixteen Boolean functions of two binary variables are shown in Table I, while Table II shows how Boolean functions are generated by combining logical operations.

With reference to table III, it will now be stated how some Boolean logic functions of two binary variables are realized by means of optical logic elements OLE where the memory material 1 is an electron trap material. In this case, the electron trap material is brought to a trap state by irradiation with blue light. Subsequent irradiation with red light releases the trapped electrons and orange light is emitted. In this case, the activator 2 will be designed as two separate, addressable radiation-emitting bodies, for example in the form of a voltage-tunable, light-emitting diode. A bandpass filter can now be used which can be arranged in the form of a layer between the memory material 1, i.e. the electron trap material, and the detector 3, so that blue and red light are blocked. Thus, only the stimulated orange fluorescence light is detected.

If bacteriorhodopsin is used as a memory material, the memory material will in this case indicate its different logical states by changes in the optical transmissivity, so that the detection takes place in absorption mode and not in emission mode as with fluorescence. An example of the realization of some Boolean logic functions of two variables is shown in table IV, where it is assumed that a photocycle is used for bacteriorhodopsin where the molecules are switched between the ground state bR and the metastable M state. Irradiation of the bR state with yellow light produces a transition to the M state which absorbs blue light, while irradiation with blue light in the M state brings the bacteriorhodopsin molecules back to the bR ground state. The molecular state can be monitored by measuring the absorption of blue light using a weak blue probe beam. With the arrangement shown in table IV, if blue light is used both for the pre-processing stage and the input signal as well as for the output signal, it will be necessary to perform discrimination by time sequencing. The photocycle involving the M state is partially thermally driven with time constants tp that can amount to several milliseconds. In order to achieve high total processing speeds, it is necessary that the optical logic elements OLE in the optical logic device OLD or groups of such optical logic elements OLE are addressed in parallel. However, the use of bacteriorhodopsin as memory material 1 provides more opportunities to realize logic circuits based on the use of the optical logic element OLE according to the present invention. It may be mentioned that both the processing of the bR state using yellow light and the processing of the M state using blue light are photochemical reactions, i.e. they are driven by photons, and that the switching speed in each case mainly depends on the intensity of the used light radiation. It is also possible to use switching between e.g. the ground state bR and the K state, a transition that occurs very quickly (xv~ 10 ps). After absorption of blue light in the bR state, the molecule is driven above the K state via an intermediate state J within a few picoseconds. The K state absorbs at a wavelength shifted compared to the absorption wavelength of the bR state, namely at a wavelength of 590 nm, and can return to the bR state by a very fast photoinduced process of at most a few nanoseconds duration. When using bacteriorhodopsin as a memory material, it can also be attractive to use the long-term stable Q state that is included in the above-mentioned branch reaction of the bacteriorhodopsin photocycle. Use of the ground state bR and the Q state respectively will provide a high spectral isolation between input light (write light) and probe light (read light) as well as a simple and direct implementation of logic circuits that realize Boolean functions. A possible disadvantage is the relatively low cycle speed between the states, but by again realizing the optical logic device according to the invention with the possibility of addressing in massive parallelism, it will be possible to achieve very high data rates.

If the optical logic device according to the invention is to be realized as an optical data processor, this means that it must be possible to realize arithmetic registers which perform binary arithmetic operations. An example of a parallel algorithm for four-bit full addition is shown in fig. 19 and will be able to be realized by logic gates with memory material based on, for example, an electron trap material or bacteriorhodopsin, cf. fig. 18. A binary half-adder simply consists of an EXCLUSIVE-OR gate for the sum and an AND gate for the ment. To realize a full addition, the meaning from the half addition of the less significant bit must be taken into account. Logic gates with three inputs are therefore essential. This would exclude the use of optical logic elements OLE according to the present invention, as they only have two inputs for a logic operation. To overcome this problem, an iterative parallel flow algorithm can be used, and an example of a four-bit addition that only needs four iterations is thus shown in fig. 19. The advantage of this algorithm is that a series of shift and logic operations can be repeatedly performed using the same optical logic element with two inputs, that is, in the case of electron trap materials or bacteriorhodopsin with light of two wavelengths. Parallel logic operations EXCLUSIVE-OR and AND can be performed by an optical logic element. The shifted intermediate output signal can alternatively be fed back to the logic device above the detector and addressing system to impinge the optical logic element with light at the input wavelengths. It is assumed that a heloptic system can at least be realized based on this principle with the use of optical logic elements OLE and where the memory material is either an electron trap material or a conformationally reactive material that can undergo a photocycle such as bacteriorhodopsin, if the activator is a light-emitting, wavelength tunable polymer diode, as discussed above.

The above-mentioned examples of realization of Boolean logic functions and an arithmetic operation are of course intended as examples, and those skilled in the art will understand that within the scope of the present invention it will not only be possible to realize such operations, but in general all logical and arithmetic operations in binary logic and with the optical logic device according to the invention configured to an architecture that implements an optical data processor with high capacity and speed. There is also nothing in the way of configuring an optical logic device OLD according to the present invention to a larger computer with a number of processors that can be addressed and work in massive parallelism. If the processors are implemented as systolic serial processors and a dynamically optimisable network topology is used, the use of proximity-addressable optical logic elements according to the present invention will offer a performance and capacity that is several orders of magnitude above conventional semiconductor-based technology and also entail advantages that only optical-based computer technology seems to have to be able to realize.

Claims (41)

1. Optical logic element (OLE), in particular a multi-state, multistable optical logic element and even more particularly a proximity addressable optical logic element to which addressing takes place directly without the use of active or passive optical elements, comprising an optical memory material (1), where the memory material (1) under the influence of an applied magnetic, electromagnetic or electric field or supplied energy can pass from one physical or chemical state to another physical or chemical state, where a physical or chemical state is assigned a specific logical value, and where a changing the physical or chemical state of the logical element causes a change in the logical value and is carried out by the logical element being accessed and addressed magnetically, electromagnetically, electrically or optically for writing, reading, storing, erasing and switching of an assigned logical value, characterized by that the memory material (1) is arranged in or on a mainly layer-like structure, that an activator (2) which generates a magnetic, electromagnetic or electric field or supplies energy to the memory material (1) is arranged in or adjacent to the essentially layer-like structure and in one with it, and that an optical detector (3) for detecting the memory material's optical response conditioned by the physical or chemical state of the memory material, is arranged in or adjacent to the essentially layer-like structure and in one with this, so that the optical logic element (OLE) constitutes one of the memory material (1), the activator (2) and the detector (3) ) consisting of a uniform, integrated component. 2. Optical logic element (OLE) according to claim 1, characterized in that the memory material (1) is arranged in the form of a first layer that the activator (2) is arranged in the form of a to the first layer (/i) adjacent other layer (/2) and in one with this or arranged integrated in the first layer (/[), and that the optical detector (3) which detects the condition in the memory material (1) is arranged in the form of a to the first layer ( li) adjacent third layer (/3) and in one with this, so that the optical logic element (OLE) constitutes said integrated component, consisting of at least three and two layers h> h\ I\- > h)- 3. Optical logic element according to claim 1 or 2, characterized in that the memory material (1) under the influence of the magnetic, electromagnetic or electric field or the supplied energy can pass from one state to another and from the other state return to the first state. 4. Optical logic element according to claim 1 or 2, characterized in that the memory material (1) under the influence of the magnetic, electromagnetic or electric field or the supplied energy can change from one state to another, permanently stable state. 5. Optical logic element according to claim 1 or 2, characterized in that the optical memory material (1) is an electron trap material. 6. Optical logic element according to claim 1 or 2, characterized in that the optical memory material (1) is a fluorescent material. 7. Optical logic element according to claim 1 or 2, characterized in that the optical memory material (1) is a conformationally reactive material. 8. Optical logic element according to claim 2, characterized in that each layer (/], l2, ly) comprises a ground mass. 9. Optical logic element according to claim 8, characterized in that the base material is optically transparent. 10. Optical logic element according to claim 8, characterized in that the base mass consists of one or more polymer materials. 11. Optical logic element according to claim 10, characterized in that more than one polymer material is used in the second (l2) and third (/3) layers. 12. Optical logic element according to claim 11, characterized in that at least one of the polymer materials in the second (/2) and/or the third (/3) layer is an electrically conductive polymer material. 13. Optical logic element according to claim 8, characterized in that the memory material (1) is arranged on or embedded in the base material in the first layer (/j). 14. Optical logic element according to claim 7, characterized in that the activator (2) is formed by one or more direct or indirect radiation-emitting bodies (2i,...,2n), the radiation-emitting bodies being arranged on or embedded in the base mass in the second layer (l2). 15. Optical logic element according to claim 14, characterized in that the radiation-emitting body (2) is accessed and addressed electrically. 16. Optical logic element according to claim 15, characterized in that the radiation-emitting body (2) is a light-emitting diode. 17. Optical logic element according to claim 16, characterized in that the light-emitting diode (2) is a polymer diode. 18. Optical logic element according to claim 15, characterized in that the radiation-emitting body (2) is a semiconductor laser. 19. Optical logic element according to claim 15, characterized in that the radiation-emitting body (2) is frequency tunable, the frequency tuning taking place in connection with electrical addressing. 20. Optical logic element according to claim 14, where more than one radiation-emitting body (2) is arranged, characterized in that the radiation-emitting bodies (2i,...,2n) respectively emit at different, preselected frequencies. 21. Optical logic element according to claim 14, where the radiation-emitting body (2) is an indirect radiation-emitting body, characterized in that the indirect radiation-emitting body (2) is arranged to be activated by an external radiation source (2'). 22. Optical logic element according to claim 2, characterized in that the optical memory material (1) is integrated with the activator (2) into a common physical structure, so that the first (/i) and second (/2) layers are combined into a common layer (/c). 23. Optical logic element according to claim 22, characterized in that the activator (2) upon the energy supply is arranged to be destroyed and then itself constitute a memory material in a permanent, stable state, or integrated with the memory material (1) leaves this in the same permanent, stable state. 24. Optical logic element according to claim 2, characterized in that the second layer (72) and the third layer (73) are arranged on opposite sides of the first layer (/]) and adjacent to it. 25. Optical logic element according to claim 1, characterized in that the optical detector (3) is an electrically accessible and addressable optical detector. 26. Optical logic element according to claim 15 and claim 25, characterized in that electrodes (4, 4') and electrical conductors (5, 5') are integrated in the other (/2) for electrical access and addressing. and the third layer (/3). 27. Optical logic element according to claim 26, characterized in that electrodes (4, 4') and electrical conductors (5, 5') are based on an electrically conductive polymer material. 28. Optical logic element according to claim 2, characterized in that adjacent to the first layer (/j) or integrated into it, a further layer (/4) is arranged to generate an electric field, the generated electric field being used to influence the response of the optical memory material (1) in the time domain respectively , the frequency domain or the intensity domain. 29. Optical logic element according to claim 28, characterized in that the further layer (U) comprises one or more electrically conductive polymer materials. 30. Optical logic device (OLD), in particular for storing data or performing logical and arithmetic operations, where the device comprises a number of optical logic elements (OLE), where the optical logic elements (OLE) are in particular multi-state, multistable optical logic elements , and even more particularly proximity-addressable optical logic elements to which addressing takes place directly without the use of active or passive optical elements, comprising an optical memory material (1), where the memory material (1) under the influence of an applied magnetic, electromagnetic or electric field or applied energy can pass from one physical or chemical state to another physical or chemical state, where a physical or chemical state is assigned a specific logical value, and where a change in the physical or chemical state of the logical element causes a change in the logical value and is carried out by the logical element being accessed and addressed magnetically, electromagnetically tical, electrical or optical for writing, reading, storing, erasing and switching an assigned logical value, characterized in that the memory material (1) is arranged in or on a mainly layer-like structure, that an activator (2) which generates a magnetic, electromagnetic or electric field or adds energy to the memory material (1) is arranged in or adjacent to the essentially layer-like structure and in one with this, for an optical detector (3) for detecting the memory material's optical response conditioned by the memory material's physical or chemical state, is arranged in or adjacent to the essentially layer-like structure and in one with this, so that the optical logic element (OLE) constitutes one of the memory material ( 1), the activator (2) and the detector (3) consisting of a single, integrated component, that the device (OLD) comprises at least one of two or more optical logic elements formed structure (S), and that the optical memory material (1), the activator (2) and the detector (3) in each logical element (OLE) in the structure (S) merge into and are continuous with the memory material, the activator and the detector in the surrounding logical elements (OLE) in the structure (S), so that the structure (S) forms a planar or curved surface body, as each logical element (OLE) in the structure (S) has a unique assignment between the memory material (1) and the activator (2) and an assignment between the memory material (1) and the optical detector (3) for unambiguous detection of a physical or chemical state in the memory material, so that each logical element (OLE) in the structure (S) can be accessed and addressed individually. 31. Optical logic device according to claim 30, characterized in that in each optical logic element (OLE) the memory material (1) is arranged in the form of a first layer (7j), the activator (2) is arranged in the form of a second layer (/2) adjacent to the first layer (l\) ) in one with the first layer or arranged integrated in the first layer (/i), and the optical detector (3) which detects the condition in the memory material (1), arranged in the form of a third adjacent to the first layer (l\) layer (/3) in one with the first layer, so that the optical logic element (OLE) forms the integrated component, consisting of at least three and two layers respectively (/j, /2, /3; l\, /3) and that each of the layers ( lu /2, /3) transitions into and is continuous with the corresponding layers (Zl5 /2, /3) in the surrounding logical elements (OLE), so that the structure forms a planar or curved surface body of continuous and mutually adjacent respective layers (/[, /2, /3; l\, l2). 32. Optical logic device according to claim 30 or 31, characterized in that each structure (S) has the form of a thin, flexible film. 33. Optical logic device according to claim 30, characterized in that the optical logic device (OLD) comprises two or more interconnected structures (Si, Sx) stacked on top of each other, so that the optical logic device (OLD) forms one of several structures (S) integrated chip or plate-like component. 34. Optical logic device according to claim 33, characterized in that an optical, thermal or electrical insulating layer (/5) is arranged between each stacked structure (Si, Sx). 35. Optical logic device according to claim 30, characterized in that two or more logical elements (OLE) which make up a coherent group in the structure (S) are assigned to an optical detector (3) which covers all logical elements in the group. 36. Optical logic device according to claim 30, characterized in that each structure (S) comprises one or more layers (76) with electrodes (4, 4') assigned to each logical element (OLE) and electrical conductors (5, 5') for accessing and addressing the optical logic device (OLD). 37. Optical logic device according to claim 36, characterized in that the layer or layers (U) are wholly or partly formed by one or more conductive polymer materials which, integrated in the layer or layers (/6), form the electrodes (4) and the electrical conductors (5). 38. Optical logic device according to claim 30, characterized in that a structure (S) is fully or partially configured as an optical memory, each optical logical element (OLE) in the memory forming a memory element that can be accessed and addressed individually. 39. Optical logic device according to claim 30, characterized in that a structure (S) is partially configured as optical logic or arithmetic circuits, or networks of such circuits, each logical element (OLE) in the circuits forming a switching element that can be accessed and addressed individually. 40. Optical logic device according to claim 30, characterized in that groups of the optical logic elements (OLE) in a structure (S) are respectively configured as memory registers, logic registers and arithmetic registers, each optical logic element (OLE) in a register and each register can be accessed and addressed individually, and so that the registers can be collectively configured into an optical data processor. 41. Optical logic device according to claim 30, characterized in that access and addressing of the logical elements (OLE) is transferred to the structure (S) assigned multiplexed communication lines.