DE2633036C2 - - Google Patents

Description

The invention relates to a method for generating Changes to the properties of a storage medium in three dimensions in which at least two each other intersecting rays of the same physical type at the same time or one after the other Act medium in the initial state and thereby effecting the property changes as well as after three-dimensional volume calculator memory manufactured using this method and optical elements and an apparatus for producing a three-dimensional volume calculator memory.

A method of this type is known from DE-OS 17 97 599 known. The procedure described there is mainly to create a real three-dimensional Image uses and aims above all inexpensive molds for other manufacturing processes to accomplish. All described in DE-OS 17 97 599 Media work with one-photon reactions or with chemical transformations due to such absorptions. These all have the disadvantage that they are too much slowly degrading intermediate states lead  which the use of such media as storage media restrict very much or make it impossible.

The present invention is based on the object a more efficient process of the aforementioned Art as well as three-dimensional volume calculator memories produced by this method and optical elements and a device for operating according to this method Specify the production of three-dimensional volume calculator memory, to not only manufacture Shapes, but also of high quality and novel optical elements and volume calculator memories enable.

To solve this problem, the invention provided that the medium only through a single electromagnetic radiation in the form of multiphoton absorption contains excitable component which over at least a temporary aroused Intermediate state into a chemically stable final state is transferred and that the electromagnetic radiation different quantum energies or Own frequencies and the multiphoton photoactive absorption spectrum of this one Component are adjusted. Next are to solve the task Volume calculator memory, a device for producing a volume calculator memory and an optical element according to the features of claims 12, 13 and 17 specified.

At the same time as the development of the invention occurred the past few years On the part of theoretical opticians such as B. Duncan Moore (Journ. Optical Soc. Of America, Vol. 61, No. 7, pp. 886-894), Luneburg, Sands and others at the Simplification and improvement of the construction more common optical systems, which by the Possibility would arise, accurate and reliable Changes in the refractive index in considerable Introduce parts of lenticular components. To now the best way was this theoretical Approaching materials using ion diffusion technology. The inventive method can be used Production of these inhomogeneous optical components apply, where it is possible to adjust the symmetry properties,  the property change rates and the Control boundary conditions completely. This area of construction options is ion diffusion or widely superior to other known methods, and in addition, the invention allows real time monitoring and a feedback is used to the Simplify manufacturing process.

The invention leads to a novel means controlled arrangement of inhomogeneities within Matter volume interaction systems between selected radiation states and thereon reacting materials that so far have only been used in the only recently discovered two-photon spectroscopy analysis and with laser-induced selective photochemical reactions were used. About the Teaching of DE-OS 17 97 599 or the US-PS used 40 41 476 goes beyond the invention additional subdivisions of the known systems Class I and the systems (interaction systems) to class II according to US-PS 40 41 476. While this previously known systems on usual One-photon reactions were based either simultaneously or sequentially in a matrix the new, structure-building Class I system Group 3 the phenomenon of simultaneous multi-photon absorption of a single one excitable type (medium component) upon excitation of radiation states different energies. The new structure-building Class II system Group 2 uses the gradual or sequential multi-photon excitation of a single one excitable type with excitation of states with different energies, the intermediate step condition is limited to the excited state. The new structure-building system of class II group 3 uses the stepwise or sequential Multi-photon excitation of a single excitable species, where at least one of the intermediate step condition  the excited state is limited. The new structure-building system of class II group 3 used the stepwise or sequential multi-photon excitation of a single stimulable type, where at least one of the intermediate step conditions Ground state is. These structured materials in excited state serve either directly or through subsequent interaction with components of the Medium for this, the structured products of the invention to create. At various remarkable Modifications of the invention can be the medium of transparency to individually occurring excitation radiation have, which allows remarkable effects that with simple photo reactions according to Grotthus-Draper are achieved.

"The active region" is defined herein as the structured distribution site within a volume of a medium in which, at the end of a sequence of directed photochemical reactions, including simultaneous or sequential two-photon reactions, amplification reactions and the like. the like, the desired physico-chemical inhomogeneity according to the invention develops. In the diagrams and figures, the active area is identified by the symbol "X" .

The presence of an active area symbolized by "X" can be characterized by the presence of radicals, ions, color structures, energy transfer agents, physico-chemical changes. "X" can also represent additional states of excitation if more than two photon mechanisms are used. For example, a reaction sequence is shown later:

where "X" additional excitation states and formed parts such. B.

can refer to, as will also be described later.

Other names have the following meanings:

hv ₁ is a primary beam, hv ₂ is a secondary beam , ¹ A _{v / r} shows an excited species in a higher vibration / rotation level of a variety of ground states, ¹ A * shows an excited species in a variety of singlets, ¹ A ** shows one excited species in a higher singlet state of diversity, ³ A * shows an excited species in a diversity of an excited triplet, ³ A ** shows an excited species in a higher excited triplet state of a diversity.

Many-photon absorption processes, which in the simultaneous multi-photon absorption method of Invention can be used are in newer Literature in detail in z. B. the book Organic Photochemistry by Robert O. Kan, McGraw-Hill, New York, 1966, Chapter 1. A special one useful review article by Wm. Martin McClain in Accounts of Chemical Research, Volume 7,  Number 5, May 1974, pages 129 to 135 describes methods to obtain two-photon spectrograms which are suitable for The invention may be useful to generalize the wavelengths and energy parameters for usable radiation sources to predict. Other useful reviews have been provided by W. L. Peticolas in Annual Reviews Phys. Chem., Vol. 18, 1967 and H. Mahr, Physics of Color Centers, H. B. Fowloer, ed., Academic Press, N.Y. 1968, and J.M. Warlock, Laser Handbook, F.T. Arrechi ed. North Holland Pub. Co., published in 1972. Another Article by H. Mahr appears in Treatise in Quantum Electronics, ed. C. L. Tang and H. Rabin, Academic Press, N.Y. 1974.

The first published description of a selected two-step or subsequent excitation of materials which are here in a novel way to use structured three dimensional Create objects (class II, groups 2 and 3) appeared in 1972 in an essay by R. V. Ambartzumian and V. S. Letokhov in Applied Optics, Vol. 11, Number 2, February 1972, Pages 354-58. But the above should also be mentioned again McClain and Mahr essays mentioned and attention be directed to an increasing literature, which with selected excitation processes for selected chemical Reactions and with isotope separation using Deals with laser radiation. Useful mechanisms including Two-step photoionization, two-step photodisassociation and photo predissociation were published in early articles discussed by C. Bradley Moore (Ann. Rev. Phys. Chem., Vol. 22, 1971, p. 387 and Ann. Rev. Chem. Phys., Vol. 23, p. 41, 1973 and Accounts Chem. Research, Vol. 6, 1973, pp. 323-328), while newer publications e.g. B. A. M. Ronn (Spectroscopy Letters, 8 [5], 1975, pp. 303-328; see also reference 1 of this article, there is a list of summary articles, and see Reference 2 of this article, there is the laser "catalyzed" Photochemistry discussed). C. T. Lin has a remedy  described to increase the effectiveness of operations that on reducing the resonance energy transition mechanisms direct excitation of a triplet state from a ground state based on the fact that for a resonance transition from a triplet state to one Singlet state a forbidden spin change transition (forbidden spinflip transition) is necessary. Very valuable calculations on the use of self-ionization resonances at the Reduction of the required performance are in detail the article by V. F. Letokhov (Spektroscopy Letters, 8 [9], 1975, Pp. 697-709), and a simple quantification formula for Photopolymerization and other processes involved in the invention used, appears in the US-PS 38 29 838 by column 12, line 28 to column 13, line 20. These notes are added here to the state of the art in laser-induced To show photochemistry that the invention uses to structured inhomogeneities with physico-chemical behavior to build.

The combinations of. Described in the following pages Materials and processes were selected to make special systems to clarify; it was not intended to give the impression to awaken that a certain material only in a certain described system can be used and not in one of the alternative systems described below.

The medium used for the process can be liquid be like B. a photopolymerizable monomer, a Mixture of monomers, a mixture of monomers and Polymers, or it can be a viscous polymer that is capable of yet another photo reaction. The medium but can also be in a solid state, e.g. B. a gel-like polymer, a frozen monomer reactive component within a matrix Plastic, a glass or a crystalline material.  

Regardless of whether the systems used to class I, Group 3 or class II, groups 2 or 3, the preferred means, the desired increase in Energy levels are to be reached at selected locations the combined effect of at least two light beams, that from the outside into the volume of matter like that be projected so that their intersection is the desired one Structure designs. Details about the light sources, the beam line and control and the structure of the Structures can be found in U.S. Patent 4,041,476 and US-PS 38 29 838 are removed. The one in these Written control and guide apparatus described adapt easily to the present system.

The size of the required power varies widely due to the quantitative change in the product obtained, e.g. B. in the trace amounts of the component generated by energy transfer compared to the polymeric mass in the case of chemically precipitable images. Example 37 contains a list of critical parameters and a formula for calculating the samples. When selecting the system to be used, the structures of the energy levels and the arrangement of the intermediate states in a particular material will help to select which of the systems described and which light source are to be used. With regard to the quantum yield, results as low as 10 ^-5 or 10 ^{-6 are} quite practical in the case of simultaneous two-photon absorption, especially where the product takes part in an amplification process as described several times in this application. Far higher quantum yields can be achieved by combining favorable intermediate levels combined with large cross sections, with the dimensions of the cutting areas being small. Values of the order of 10 ^-50 or 10 ^-48 cm² / watt / cm² can be achieved.

Processes with relatively low yields are most satisfactory in connection with effective systems, such as. B. the polymerization initiated by methylene blue, where a concentration of methylene blue in the order of 10 ^-6 mol / liter can be effective. In this case the polymerization yield can be of the order of 10⁶ molecules polymerized with each excitation, while some similar systems give up to 10⁸ molecules produced per excitation. The systems with the greatest effectiveness can be expected from processes with similar polymerization yields, which at the same time allow a photon yield in the size of ½.

Because of the relatively low probability really more simultaneous Three-photon absorption is one such system not very practical. The use of many photons and in particular of three-photon absorptions in series or mixed in series and at the same time, however, is very practical and has special advantages, including e.g. B. high contrast.  

It must be noted that in this description only simple systems are shown. The permutation of such simple systems in connection with each other (e.g. a Three-photon system that consists of simultaneous absorption of two photons with subsequent absorption of a third Photons) is in the sense of this revelation.

Such systems can be developed using the many-photon absorption through the presence of those in resonance or intermediate states almost in resonance in the System is made possible. In such cases, the difference between simultaneous and successive processes blurs and they are useful when both contrast and productivity should also be maximized. The first comes Photon in such a system closer to an absorption state and closer and finally within the line width of this The second photon from the first excitation level resonate to the second level. From the point of view effectiveness and contrast are such systems that resonating or nearly resonating Intermediate states are preferable in many cases.

When using a system with successive excitation states, in which a photon with the wavelength λ 1 causes the excited state A * with the lifetime Y , where Y is very large, it is in the event that the excited state is a second photon with λ ₂ to achieve a further excited state A ** of the service life

absorbs, obviously, that if the photon densities are the same in the two photon processes, this process is much more likely to occur. The probability of obtaining A ** depends directly on the life Y.

If the process just described is repeated with a further step for generating A ***, whereby the active region is generated, then it becomes possible to scan the volume of matter in a fan shape with photons of three different wavelengths, namely along lines that are perpendicular to the respective scanning direction stand. An input is given in the form of the usual Cartesian coordinates x, y and z , and the scanning takes place one-dimensionally. This and the lower power required, plus the added benefit that a background response that is not due to the image to be generated is reduced.

Particularly preferred embodiments of the method according to the invention or according to this Processed products are the See subclaims.  

Because of their generally greater usefulness, following the design and operation of Class I, Group 3 systems, where photons of different energy and wavelength are used are described in more detail.  

The simplest example of such a system when used the simultaneous absorption of two dissimilar photons is:

In such systems, the frequencies, and thus the energy values, are different from hv ₁ and hv ₂ and selected so that they meet the following conditions:

E (hv ₁) + (hv ₂), (hv ₁) < (hv ₂) and E <2 (hv ₂).

Under these conditions, a very intense beam with low energy photons (hv ₂) is cut with a low intensity beam but with higher energy photons (hv ₁).

A system of this type is recorded in Fig. 22. The typical absorption curve of a photoreactive material in a conventional one-photon process can be seen on the left, while an approximately congruent two-photon absorption spectrogram is obtained on the right, which was obtained by the McClain method. Using the Group 2 process with two identical photons, an intense beam of wavelength within the range of the two-photon absorption spectrogram would be used to initiate the reaction. In the preferred type according to group 3, which uses unequal photons, at least the high-intensity (hv ₂) beam must be particularly excluded from the area of two-photon absorption. In Fig. 22 hv ₂ is shown as originating from a pulsed ruby laser and hv ₁ as originating from a pulsed argon laser. The procedure for systems according to Group 3, Class I can be understood from the description that follows.

As described above, the radiation sources are in the following complementary relationships:

• 1. The laser R has a low energy per photon and a high intensity of the beam.
• 2. The laser G has a high energy per photon and a low beam intensity. (Note that the amount of energy per photon, for example, is not confused with the energy per pulse length.)

The permissible, necessary and forbidden values for the photoactive absorption spectrum in the two-photon mechanism are provided by the wavelengths of these two radiation sources. The photoactive absorption cannot extend into a range in which the wavelengths are longer than those of the laser R (the high-intensity radiation source), nor can it form an active range if the wavelength is shorter than the wavelength λ _X in:

Should the selected photoreactive material (or the sensitizing material or the energy transfer agent) have an absorption curve that extends into the longer wavelength range, then two photons from the radiation source with higher energy will be sufficient to drive the reaction along the entire radiation path of this radiation source. If the absorption spectrum is limited to a region that is shorter than the wavelength g _X , then the active region will not be generated at the intersection due to the insufficient energy. At least part of the absorption spectrum must extend into the area between these two limits so that the necessary conditions are met. As previously stated, if a given material, photoreactive component, and a number of energy sources are to be used successfully, the other ingredients must be selected so that spurious absorption by unreactive materials, thermal reactivity, and undesirable side reactions are excluded. Such preventive measures are part of the task of the person skilled in the field of photochemistry. Those skilled in the art are aware of the fact that, although the generalized description given above of the limitations in the relationship between absorption structures and radiation sources are generally useful, structures of the photoactive spectrum are generally present in the materials which are capable of modification. The absorption spectrum of a material is not always identical to the photoactive absorption spectrum. For example, the photoactive absorption spectrum may coincide with the wavelength of a radiation source, and this would constitute an exclusionary condition that tends to result in spurious imaging along the radiation path by common one-photon reactions. On the other hand, this absorption cannot be photoactive in nature, and then the main problem is that the effectiveness of the process would be weakened or lost entirely due to the unnecessary absorption, and that problems could arise from the heating of the material. Some other considerations that are important to the invention are briefly discussed below for clarification, although they are not new to those skilled in the fields of photochemistry and two-photon spectroscopy.

When designing a two-photon reaction type system, cross-sectional factors that are greater than about 10 ^-50 to 10 ^-48 are generally avoided, except for systems that occur near the resonance region where the upper feasibility limit is substantially the same as that in successive operations. The effectiveness of photon absorption, which can be achieved with successive absorption, is approximately achieved with simultaneous two-photon absorption processes that take place near the resonance.

Generally, systems with resonance transitions are preferred if high productivity is desired. The probability a two-photon transition is inversely proportional the distance from the resonance state (e.g. from a one-photon transition) of the intermediate state, compared to the Photon energies. Ideally, this distance disappears until close to the match (with full match it is a follow-up process) at the very top of the absorption line and thus reduces the energy denominator in the absorption cross section for two-photon processes as much as possible.

The special value of systems where resonance or fast resonance occurs, lies in the effectiveness and high yield, which they allow are justified. In the expression

is <0 / μ / 1 <proportional to the one-photon absorption coefficient to an intermediate level, and <1 / μ / 2 <means a second one-photon transition from the intermediate state to the final state. ε _i - hv represents the energy level difference between the photon hv ₁ and the intermediate energy state. It can be seen that the probability of these two photon transitions is the product of the two absorption coefficients <0 / μ / 1 <and < 1 / μ / 2 <is proportional, divided by the energy distance between the intermediate level and the photon energy hv ₁. If the distance at the mean value of the photon energy is small, then the energy denominator is small and the probability (and the yield) is very large. If the distance = zero, then we no longer have a simultaneous system according to class I, but a follow-up system according to class II. In order to obtain a strong transition and a high yield, an intermediate state or intermediate states are used in which an input Photon transition is very possible and has a high energy value, and at which there is an intermediate energy level that is only slightly higher than the energy of hv ₁.

As far as productivity is concerned, it is also particularly important to select materials that have a reasonable lifespan for the excited states for this particular purpose. For example, a long-lived excited state can result in energy transfer to neighboring molecules that occurs so often that the resolution deteriorates so that the resolution and the yield are not compatible. In general, it can be said that species with extremely short lifespans produce less fertility than species with lifespans in the order of 10 ^-5 to 10 ^-9 seconds. Obviously, systems that are used in high-speed computer operations must be excluded.

It is also important to know the lifetimes of the excited states in relation to the energy balance of a given process consider. For example, it will be in a follow-up system using a continuous wave laser as a radiation source and a pulsed one second radiation source is operated, desirable be in an excited state that is long enough stops to get enough photons from the weaker radiation source to record. Few continuous wave radiation sources  are energetic enough, even if they are focused, around simultaneous operation without an extremely large waste of energy operated together with a pulsed laser to become. For this reason, in most systems with simultaneous operation, both lasers pulsed synchronously.

An alternative mechanism for direct excitation of a molecule became a triplet excited state in the ground state by C. T. Lin (Spectr. Lettr., 8 [9], 1975, pp. 901-913):

Because of the longer lifespan of the triplet state the singlet state and because no energy through resonance-energy transition is lost (for a resonance transition from Triplet to singlet state is a prohibited spin change transition necessary), this mechanism is considered to be more productive as the stimulus to a singlet state.

Because the preparation of a full two-photon spectrogram is very often a tiring and boring process some general principles are now set out, which often the selection of suitable radiation and radiation sources allow for practical work with the invention, if only that One-photon absorption spectrum and the molecular properties, such as B. symmetry properties, location of the different energy levels, which are characteristic of the photoreactive material, are known. This information allows the expert to the field of spectroscopy and two-photon spectroscopy, very often predict the energy levels, the two-photon transitions allow, and also the approximate strength of this Predict transitions. For example, almost always when  an absorption peak of a two-photon transition does not occur at a point twice the wavelength corresponds to the one-photon absorption peak, with something such a transition may be present at higher energy levels. in the generally the lowest energy transfer becomes the allowed Be a photon transition, and it may as well be the allowed one Be two-photon transition but it's unlikely that the lowest transition is the allowed two-photon transition and that the one-photon transition is prohibited.

The materials where the prediction from the one-photon spectrogram out of agreement with the two-photon spectrogram suggests are those with strong molecular symmetry, a quality that will be known to the examiner. The following measures are used as a general rule for examples given where symmetry properties and vibrational flows allow the assumption that the one-photon and the Two-photon transitions from each other as described above depend. In general, it is possible from well-known published experimental data showing the one-photon behavior relate to photoreactive material to determine which two-photon transitions are allowed and which are prohibited will be. Such predictions based on theory Principles are less useful when the energy values of the transitions to be determined or when said should be whether or not a certain energy state occurs with a certain symmetry at a certain energy. Because the field of two-photon spectroscopy is fairly new is such information in the literature in general not easily accessible, and with some interesting systems one becomes experiments with two-photon spectroscopy methods have to apply. However, it will not always be necessary laboriously complete the two-photon spectrogram  to establish the information necessary for the invention to obtain. If that is under observation Medium can be added directly to provide useful reactions to be recorded (e.g. by fluorescence emission or by switching in the refractive index or in the absorption behavior), becomes a simple one Trial series are often sufficient. Such a shortened one The process is carried out with a tunable radiation emitter (e.g. a tunable laser) that performs the likely Range of energy values covered, as well as another radiation source (e.g. a source for Class I, Group 3 systems with lower photon energy, but higher intensity) that is aimed at the sample at the same time, and with a Observation system to track the desired reactions while they're changing the first radiation source occur. If radiation is emitted during the process, will advantageously be a photodetector system for detection use. If a change in the refractive index or if polymerization is to be achieved, the display value of the sample can be detected if one is not photochemically sends out active beam and measures.

The following is indicative of the process that is required if a photoreactive material is given, its Two-photon reaction spectrum is known or estimated and the required lasers should be selected.

To simplify the case, it should be assumed that the Material consists of only one type, e.g. B. from one Monomer that can polymerize and that precautions have been taken to non-selective thermal decomposition to avoid. If the operating mode according to class I, group 3 a first laser must be selected first usually with a commercially available ruby laser  high power yield that emits at 694 nm. If the known or estimated as possible two-photon absorption to be used, which is a photopolymerization of the monomer, you can refer to Table 10, which was calculated in case a ruby laser was used becomes. Column 1 of the panel shows an area more photoactive Absorption wavelengths from the ultraviolet to the visible Light entering the two-photon absorption properties of the selected medium is adjusted. Under use of the formula given in Kan's work mentioned above has been:

we can derive the energy in kcal / mol required to initiate the photoreaction in relation to the specific laser wavelength. In the present case, the emission wavelength of the ruby is λ = 694 nm, and the power required for a specific absorption range derived therefrom is shown in column 2 of Table 10.

Depending on the optical density and dimensions of the medium can be a selected activation wavelength be used in the area of peak absorption, or with large volumes, in the rising range or near the Foot of the absorption area. In most cases it be the best to use energy sources that are of interest Area are focused. Now the laser wavelength of a beam at 694 nm and an absorption range for example, 380 nm is fixed, can be used of the formula

determine the frequency that is predefined for the second laser and that in this case is indicated in the third column of table 10 as b = 846 nm or shorter.

Examples of Class I, Group 3 systems with two-photon absorption using different frequencies stated the following:

1. A cell filled with diphenylcyclopentadiene solution is illuminated by intersecting beams which correspond to the "wavelengths" 9431 cm ^-1 and 18 862 cm ^-1 (hv ₁ and hv ₂). If desired, a single laser can be used to form the first beam path through the medium, and unabsorbed radiation from the back can be passed through a KPD crystal to produce the second harmonic (to form hv₂ ) and through a filter (to eliminate hv ₁), and then be directed back to an optical path that allows the beam to re-enter the medium from a new entry point so that it intersects the original beam path. This example shows fluorescence known in the art and any fluorescent structure is not one of the examples of the structures of the invention that do not emit radiation. In order to use these materials in accordance with the invention, it is necessary to add an additional component to the mixture which responds to the internal fluorescence emission to create a secondary region and the non-radiating, desired product.

2. Chromium carbonyl is in methyl methacrylate and azoisobutyl nitrile dissolved and heated to 50 ° C until the polymerization is complete. Piercing this medium two each other  intersecting rays, as described above, results a two-photon absorption that has an intense yellow color causes, which is stable at 77 ° K, but at room temperature fades in a few hours.

3. Barium acrylate is dissolved in a hot gelatin solution, which contains methylene blue and p-toluenesulfonic acid. The solution is cooled until a gel forms. Two-photon absorption, as described above, at the intersection of the Radicals radiate, which polymerize the barium acrylate, creating an opaque, light-scattering image made of polymers.

4. A frozen glass of acrylonitrile in which a larger one Amount of compounds such as benzoin or azo-isobutyl nitrile which form light-activated radicals illuminated in a similar way. Two-photon absorption of the Catalyst generates radicals that are light-scattering, insoluble Form polymers.

5. A solution of a photo crosslinking agent such as. B. 2-methylanthraquinone or 1-chloroanthraquinone in one suitable monomer such as vinyl acetate, styrene, methyl acrylate etc., which contains a photopolymerization catalyst, the Absorption spectrum is similar to that of the crosslinking agent, is frozen and exposed to two intense light beams. The monomer is polymerized and crosslinked at the intersection. After exposure, the glass is melted and the illuminated ones Areas are used by the matrix with or without separated from solvents.

6. When lighting, instead of frozen glass, gels can be used to be used. A heat activated polymerization catalyst can be added in example 4. The  Solution is then heated until it gels and then how described above, illuminated. A catalyst like azoisobutyl nitrile would be suitable for this system because it is activated by both heat and light. Solvents are used to separate the image from the matrix used.

7. A light-crosslinkable, photosensitive polymer is used with or without the use of sensitizers and additional crosslinking agents, as described in FIG. 5, two exposed to intense light beams so that at the intersection the bundle of two-photon absorption occurs. The cross-linked polymer is then made using solvents separated from the matrix. Examples of polymers that suitable for this system are: polyvinyl tin amate, polyvinyl benzophenol, Polymers containing diethyl dithiocarbamate Anthracene, azides, acrylic azides, sulfonyl azide, acrylic diazide, a-diazoketones, Furylacryl and allyl groups, stilbene, azidocinnamates, Polyacetylenes and polymers in which the photosensitive Group using isocyanate compounds polymeric structure and the urethanes form certain Olefin polymers with sensitizing halogen compounds and polyesters made from tin amylidene malonic acids and related mixtures were formed. Other photosensitive Polymers by means of a photodimerization mechanism network or as a result of photolysis one crosslink photolabile group, either with the polymer chain connected or separated from it can be in be substituted and used in the same way.

8. Containing a lactoflavin or a similarly acting color thiolated gelatin is, as described in Example 10, illuminated. Network the thiol groups in the overlap area,  which gives an insoluble picture.

9. A gel cross-linked by mercury chloride, the one contains light-reducible paint, as in Example 6 described, illuminated. In the area of beam intersection the mercury ion is reduced, which crosslinks the Gels picks up. So here is a negative working system that can be used to create a cavity.

10. A clear matrix that contains a high proportion of a halogenated Resin and, if necessary, other halogenated Compounds and zinc acetate or other chemical compound contains a Friedel-Crafts catalyst in the presence of a halogen forms, is illuminated as described above. At the intersection of two intense beams suitable frequency, the catalyst is formed and caused Degeneracy of the polymer and colored compounds. These images can be intensified using heat will.

Now there will be Class II, Group 2 and Group 3 presented that use a gradual multi-photon absorption. These systems are from mechanisms of stepwise two-photon excitation developed recently as analytical and chemical processing techniques have been used. A important system of this kind emerged from the gradual Process first described by Ambartzumian and Letokhov in 1972 has been. Differentiate the systems according to class II, group 2  differ from those in Class II, Group 3 in that the former only have excited intermediate states, usually singlet or triplet states while the latter use at least one basic state in between.

The more excited state or its precursors can be one higher vibrational state, higher rotational state and / or a higher electronic state. The Transition from the precursor to the desired excited state must be done before relaxation of the vibration or electronic State occurs or before the excitation energy can be passed on to neighboring molecules. In some In cases, this condition requires the use of highly intensive or pulsed laser light sources.

There are three basic types of reactions under the division of the successive two-photon excitation states fall over intermediate reactions.

In the above mechanism, the power requirement for the 1 Av / r state is relatively low, and as a result, it is convenient to use a low or infrared energy wavelength for hv 1. Examples of such reactions can be found in the article by VS Letokhov (Science, Vol. 180, 1973, pp. 451-458).

The second type of sequential two-photon reactions with intermediate excited states can be represented as follows:

11. An example of such a reaction sequence occurs when an azulol solution is illuminated by a primary beam of 530 nm and a secondary beam of 1060 nm. The primary beam lifts the azulol molecules along its path in an excited vibrational state of the lowest singlet S ₁. If they are no longer excited, these molecules return to the ground state without fluorescence. In the overlap area. in which the two beams act one after the other, the molecules in the excited state S ₁ are raised by the secondary beam to the S ₂ state, and an emission of fluorescent radiation occurs.

Although there is little theoretical understanding of the underlying Operations exist, a third is sequential Reaction with two-photon excitation is described as follows:

In this case it forms a molecule that has the appropriate energy Wavelength can record an excited Singlet state, which then makes a transition outside the system to form a triplet state. These triplets cannot form radicals and images through reactions cause and soon decay to the ground state when they are no longer stimulated. However, they become the radiation exposed to an appropriate frequency so they can form excited triplet states which are highly reactive and can initiate the various desired reactions. When using this system, the primary beam generates triplet States along its path and the secondary ray rises  the triplet states to excited triplet states at the intersection points.

The big advantage of systems that are at least two different Combined use of laser wavelengths Systems based on the effect of intense photon flux based on a single wavelength lies in the substantial lower performance requirements and the flexibility of Wavelength in the laser with high energy strength that enables when connected to a tunable light source is used with low power. The power requirement can 1/1000 of that at a single wavelength is required, and since in the case with two wavelengths the radiation power in the selection step is small and the vibration / rotation lines of the molecular Absorption does not widen significantly, it becomes much easier activate special components of the medium.

In order to operate a system according to scheme (3) with minimal power, the excitation according to A * will normally be carried out by a tunable laser, the wavelength of which is selected in such a way that it excites the lower vibration levels, the absorption cross sections being relatively large. To compensate for the molecular inharmony, the wavelength can be stepped gradually across the appropriate lines of the lower excitation states to keep the excitation in resonance, thereby keeping the performance requirements low when occupying the first vibration levels. The high power laser is then used to drive the higher excitation levels with generally smaller absorption cross sections that require less accurate wavelength selection.

In many cases, the greatest effect of the energy applied is achieved by allowing the radiation to impinge in successive pulses so that the photons hv ₁ are followed by the photons hv ₂ and that the time from the start of the hv ₁ pulse to the end the hv ₂ pulse is much shorter than the life of the first excited intermediate state. Radiation sources suitable for the radiation beams can be divided into two general groups.

The first group is made up of lasers with moderate power and variable wavelength in the infrared for selected excitation of molecular vibrations, and in the visible range for Electron excitation is formed by atoms and molecules. Such lasers include the spin change class, which is generally the Range between 5 µm and 15 µm, or the high pressure Gas lasers in which the lines of rotation overlap each other and form very wide reinforcement bands that the Range between 2.5 µm to 12 µm with a high level of performance cover, or Raman lasers, where pumped with Nd glass which cover the range from 1.2 µm to 2.5 µm, or lasers with organic colors with frequency control, covering the range from 0.4 µm to 1.2 µm. Other Radiation sources with adequate control of output quality can of course also be used.

The second type of usable laser has a high power output in the ultraviolet, it does not need to have a wavelength adjustment, but they provide a power density (E ₂) to such an extent that

where σ _phd and s _phi mean the photodissociation and photoionization _{cross sections} . Ruby lasers (with a second harmonic of 3.6 eV) and Nd glass lasers (third and fourth harmonics with 3.5 eV and 4.7 eV) and nitrogen lasers with wavelengths of 337.1 nm, (3, 7 eV) can also be used, such as hydrogen lasers (160 nm to 110 nm) or the Xe lasers at around 170 nm. From the standpoint of energy consumption and efficiency, the newly developed noble gas halogen lasers are in the range work from 250 to 350 nm, particularly attractive. These latter lasers, e.g. B. complex xenon and chlorine lasers result in high efficiency (ie yield of photons per unit of electrical energy can be different orders of magnitude better than with argon ion lasers). Such radiation sources with high photon energy are particularly valuable when free radicals are desired in the active region, since they make them accessible even to smaller molecules. A variety of properties are shown by the structured results of the following examples.

12. Tetramethylphenol diamine in an EPA matrix at 77 ° K form a structure colored in gorgeous blue when it against an overlap of rays with 340 nm and 400 nm is moved. The color stems from education of a TMPD radical cation that also uses can be used to catalyze polymerization. The Color also forms in methane or propylene carbonate Solutions, and similar systems can be prepared if you have triphenyl, 3,4-benzopyrene or diphenyl in boric acids Glasses used.

13. Beta naphthol, which is in a polymethyl methacrylate matrix is exposed to two rays, the singlet band and are adapted to the triplet band of absorption, form a semi-stable yellow radical at the intersection of the two beams.  

14. Naphthalene in a solution of a monomer, one difunctional monomer (to create crosslinking) and ethyl iodide is exposed to two rays of light, one of 313 nm and a beam in the visible range of one Wavelength absorbed by the triplet of naphthalene becomes. The resulting triplet generates radicals, which polymerize the monomer directly or indirectly and network. Other compounds instead of naphthalene can be used to generate similar radicals are acridan, 9-phenylacridan, toluene, naphthol, acriflavin and acridine.

15. Orotinic acid and similar compounds also form excited ones Triplet in two-photon processes. These Triplets can contain hydrogen atoms from suitable donors deduct, forming radicals that are effective Catalyst for polymerization and possible crosslinking processes represent.

16. Benzoyl and oxalyl chloride and benzophenol, in one Polymer dissolved, form an excited state, which crosslinks the polymer and makes it insoluble, with a similar two-photon mechanism is effective.

In the new Class II systems described above, Group 2 happened through the absorption of the secondary beam a molecule in an excited state and a distinction was made between excited singlet and triplet states. In the systems to be discussed according to group 3 is this distinction is not important because of the secondary beam is absorbed by a molecule or atom in the ground state and in the following section the pontic can  excited state either a singlet or a triplet be.

The intermediate systems of group 3 that are in the basic state can be prepared so that one or both of the reactions is irreversible. This is an example Scheme (6)

17. Such a system is prepared by using a polymethine-cyanine color, which generates a mono-cis isomer under radiation with (hv ₁), which reacts to radiation with (hv ₂) and a colored di-cis isomer results. In a similar system, Bengal-Ros' is present and is converted into a de-iodinated derivative by (hv ₁), which in turn is converted by (hv ₂) to fluorescein, which results in a colored fluorescent compound and a catalyst for polymerization. However, these non-reversible systems can only be used for a limited group of simple figures.

The next scheme (7) shows a more useful reversible one sequential two-photon reaction shown:

In this case, the absorption of the (hv ₁) photon by component (A) causes the conversion to component (B) . The absorption of the secondary photon (hv ₂) by B creates a radical or a colored compound, or an energy transfer agent, etc., as previously described.

In the areas where (hv ₂) was not effective, compound B disintegrates back to compound A. This decay can be caused by absorption of light or thermal energy, and can be accelerated by suitable irradiation if the desired rate of reversal and occurrence cannot be achieved with the ambient light and heat present. Examples of such systems are discussed below.

18. O-methyl and O-benzophenone, which reversibly photo-enolize after absorption of ultraviolet light, are suitable materials. These enols react when irradiated with a blue (hv ₂) photon to form semi-stable cyclic compounds of yellow color.

19. Similar reactions can occur when using 2-benzhydryl 3-Benzoylchromon and its analogs can be obtained. The dihydrobenzofurans can also take advantage of the photochemical Ring opening used in conjunction with photocycling will. The related furil chromones do the same a photochemical rearrangement between non-fluorescent and fluorescent isomers through what they are special, purposes described in the following example are extremely useful makes. Additional information can be found in Huffman et. al., J. Amer. Chem. Soc., Vol. 92, 1970, p. 599 and Zweig, J. Pure and Applied Chem., Vol. 33, 1973, p. 394.

20. Another such system uses isooxazoles, which convert to azirenes when irradiated with the first photon (hv ₁), are converted to isooxazoles by irradiation with (hv ₂) and result from the intermediate state azirine by irradiation with (hv ₃) oxazoles . These and similar materials are particularly interesting for the invention, since only one of the forms (oxazole) fluoresces. In this way, the structured distribution of oxazole can be used as a reinforcement intermediate or especially as the active part in a computer storage system in which the bit information is in the form of an array of locations in a three-dimensional volume, which fluoresce or are capable of stimulated emission.

21. Other reversible systems according to group 3 can be prepared by using C-nitrose compounds that form stable dimers in aqueous or organic solutions. These dimers can be decomposed to monomers by either Heat or ultraviolet light is used. Please refer also scheme (8).

In this system the lifetime of the monomer depends on that special nitrous compound, as well as the chosen solvent and the temperature. The monomer has opposite the dimer has an absorption band in the visible red. The light absorbed by this band photolyzes the monomer and generates radicals. Certain dinitrose compounds, such as. B. 1,4-dichloro-1,4-dinitrose cyclohexane can be used in the same way be used.

With a change in the method, colored compounds can can be obtained when the radicals by color-forming Connections added to the medium are captured will.  

Another variation of the invention uses photochromic Materials that are usually only between two states switch back and forth as shown in scheme (9):

Scheme (9) shows the straight-line one-photon process used in US Pat. No. 4,041,476 and US Pat. No. 3,6 09,707 to produce colored number images with a photochromic matrix. In the practice of the invention, instead of using a write and erase combination of hv ₁ with hv ₂ as shown there, a color image can be obtained by using the correct combination of radiations to achieve two-photon transitions and - Get coloring in the selected areas. This mechanism is much more flexible and results in a more useful technique for complicated patterns. It can be shown as follows:

Of course, the many-photon excitation systems, used, any of those described in this application, or combinations thereof.

22. Suitable photochromic materials are also the 6,6'-diethoxithioindigo colors and their derivatives, which can be switched by optical influences between the cis and trans states when two wavelengths hv ₁ and hv ₂ are used. The two isomers have different colors and properties, including the fact that only the trans isomer fluoresces. An advantage of these materials is a very high increase in quantum yield at high temperatures (90 ° for some epoxy resins), which gives stability at low temperatures after an image is formed at a higher temperature.

23. For this process are also those in US-PS 33 29 502 epoxy to use. These connections are thermally stable and can be between colorless or light yellow and red colored states will.

24. In the same way gives N, N'-diacetylindigo that in xylene and melted polyvinyl acetate, after which Cooling down a very rigid polymeric solution Exposure to blue (458 nm) light in the flux-red translucent Configuration transformed. Like the switchable indigo colors Derivatives of Example 22 fluoresce the diacetylindigo color derivatives only in the trans form, so that they both can be used in memory constructions based on Light emission are based, as well as in those based on different Light transmission.

Additional details, the properties of the polymethine colors (Ex. 17) in the area of excitation emission, in addition the description of the use of optical structured Inhomogeneities in laser structures caused by this invention can be generated three-dimensionally at Melishchuk (Spektroscopy Lett. 8 (9), 1975, p. 669). For further information about these properties in the oxazoles (see example 2) are in Abukumov et. al.,  Spectrosc. Lett. 8 (9) 1975, pp. 651-667, as well as at Andrejeschtschew, Baroni, Kovyrzina, Rozman, Shoniia in Akademy Nauk, pp. 64-66, Adrova, Koton, Ranov and Florinskii in Akademy Nauk, pp. 39-41 (the last two give in English Translation also includes information about scintillation that is there too is where the excitation radiation is a particle radiation instead of electromagnetic radiation). The memory processes and the amplification processes can be activated by two- Include photon or one-photon systems (see U.S. Patent 40 41 476).

More information about these materials can be found in one Articles by A. Zweig, J. Pure and Appl. Chem., Vol. 33, 1973 S. 389-410 and the references 21, 22 and 23 named there being found. There is also information in an essay by A. Zweig, W. A. Henderson jr. and K. R. Huffmann that of American Cyanamid Co., Chem. Res. Div., Stamford Connecticut, under the heading "Intensity Dependent Photoimaging Systems "was pre-printed. Also Recommended: G. R. Bird, Symposium III, Unconventional Photographic Systems from October 20 to 23, 1971, SPSE Abstracts P. 79 and by the same author in Photographic Science and Engineering, Vol. 17, No. 3, May / June 1973, pp. 261 to 267.

An important modification of the invention involves use additional components that are added to the medium and can sensitize it for different purposes. Such sensitizers are generally capable of such radiant energy, to which other components do not respond and enough energy in the process of training the structured Transfer product distribution to a recipient.  

For example, the use of sensitizers can Reduce the formation of spuriously excited triplets in the primary beam path. These unwanted suggestions can occur when an overlap between the band of ground state singlet absorption and that of triplet-triplet absorption is (however, this is rare because generally with the transition from the ground state singlet to the state of the first excited one Singlets are associated with a much higher energy than corresponds to the lowest triplet-triplet band). A more common one Overlap could be of the type T₁ → T₄:

The use of sensitizers can also weaken the Reduce primary rays as they are in lower concentrations can be used. They can also be used to to increase the yield of triplets.

There are a few examples of sensitization reactions specified in class I and class II systems; however, it should be noted that the number of the possible combinations is very large, and like the others Examples of this document are only for clarification thought.

The following schemes give some awareness mechanisms class I.  

Scheme (12) shows the absorption of two dissimilar photons through a sensitizer using the singlet Singlet interaction or fluorescence. The following Schemes (13) and (14) show singlet and triplet reactions with awareness.

The following schemes and examples show sensitization mechanisms class II. In a group of such sensitized Reactions, the sensitizer absorbs the primary beam, and the energy is on a molecule in the ground state transfer:

Sensitization occurs in the two systems above by a singlet-singlet interaction or by Ab sorption of fluorescent radiation. Although there is little theoretical Knowledge of the details of these energy transfer mechanisms, the knowledge from practical experience is sufficient for ge present purposes that it is only necessary that the emissions spectrum of the donor and the absorption spectrum of the acceptor overlap each other. The light used only needs the waves length that is absorbed by the sensitizer, the acceptor can be completely transparent.

Scheme (17) shows triplet-triplet sensitization, where, like above, the energy of a molecule in the ground state is transmitted.

25. An example according to the scheme (17) can be prepared if, for example, 14 benzophenone as Sensitizer and then adds the wavelength of the primary beam changes to 365 nm. This wavelength is made from pure naphthalene not absorbed.  

In the following systems (Schemes (18) and (19)) the Secondary beam absorbed by the sensitizer, and the energy is transferred to the product of the primary beam. In the scheme (18) the sensitizer transfers its energy to an excited singlet, while in scheme (19) the energy of an excited triplet is fed.

In another significant variation of the invention, the structured distribution of product X is used as an intermediate step in the production of the final product. In a variant of this variation, X is an energy transfer medium that can absorb energy in the form of electromagnetic or particle radiation below the excitation energy. In a simple case, the distributed product X can be a distribution of fluorescent molecules that generally do not fluoresce in any of the radiations used to generate the structures, but which begin to fluoresce under selected radiation conditions and thus transfer energy to other previously inactive photosensitive mechanisms , such as B. on a polymerization process. The advantage is that a single fluorescent molecule can transfer thousands of photons per second to an acceptor system. In this way, the original structure creation process of Class I or II is subjected to a large amplification, whereby at a low concentration of X, a considerable amount of the end product is simultaneously produced. This is particularly advantageous when X is obtained by relatively ineffective two-photon absorption processes. This process can be represented schematically as follows, where L denotes the receptor system:

Depending on the demands placed on the resolution, a second component that is used to absorb transmitted energy, such as described in the previous section is capable, in general a higher absorption coefficient or higher reactivity on the energy transfer mechanism and also higher Must have concentration in the medium if the requirements to get bigger at the resolution. It is quite common  prepare concentration tables for specific materials, which is the minimum value of the molar absorption coefficient against the value of the desired resolution. This same Consideration is also on the different energy transfer mechanisms, such as fluorescence, emission / absorption, the Mechanism of energy transfer and other types of energy transfer, that don't depend on and in the first place function through molecular contact and the expert in general than different forms of intramolecular radiationless Transitions are known to be applicable.

Examples of such awareness and reinforcement systems are given below.

26. A color precursor or pre-color in a clear matrix is exposed to two intersecting light beams of adequate energy so that two photon absorption processes, as previously described, result in a structure of distributed colors. The color (see below) is selected according to its ability to sensitize the decay of the color precursor via a photon reaction (T → T energy transition) resulting from the absorption of the long wavelengths of the scanning beam or a separate developing beam. This is shown in scheme (21):

Such a system can be prepared in a transparent Matrix, the amines, such as diphenylamine or N-vinyl carbazole together with an organic halogen, such as. B. iodoform or Carbon tetrabromide. The halogens and the amines combine become a complex that, when focused on Ruby laser beam is exposed to a small amount of one Color generated that magnified by exposure to red light can be. See also Fotland, J. Photogr. Sc., Vol. 18, 1970, P. 33, Hazy & Petro, Laser Focus, Vol. 8, 1972, p. 32.

27. Stable fluorescence can also be Photon absorption systems are generated using the Fluorescent precursors found in Zweig (J. Pure and Applied Chem., 33, pp. 389-440). Among the useful reactions there are oxidative cyclization, dedimerization, Tautomerization, rearrangement, elimination, oxidation, substitution and reduction. The preferred materials are in greater detail in the section on fluorescence emission storage discussed at the end of this document and they include use the cleavage of photodimers by light into fluorescent Monomers (Salmon and Chandross, Analytical Chemistry, Vol. 45, Dec. 1973, p. 2446), the photochemical generation is fluorescent Cyclohexa-1,3-dien by ultraviolet light of one wavelength of less than 300 nm when using beams with longer wavelength and two-photon absorption according to US-PS 38 99 678, and the transition from cis to fluorescent transisomers in the Indigo color series (J. Phys. Chem. Vol. 72, No. 8, Aug. 1968, p. 2817).

George R. Bird has an important group of new energy transfer systems and means in Phot. Sc. and Engineering, Vol. 17, No. 3, May / June 1973, pp. 261-267. Bird describes  other direct intramolecular energy transfer systems in his U.S. Patents 36 22 316 and 36 22 317.

In another variation of the above, the product (X) can be a photocatalyst. A photocatalyst differs from an energy transfer agent in that it is consumed in the formation reactions of the scheme below. These are recorded schematically and followed by examples:

28. A compound (A) which can form a polymerization catalyst (B) by means of a photoreaction is dissolved in a suitable monomer or in a crosslinkable polymer. Two-photon absorption with intersecting beams is used to produce the active photocatalyst (B) in the desired structure. The matrix is then exposed to some type of radiation that activates the catalyst (B) but not (A) . The compound (A) can also be a polymerization catalyst which has been chemically modified or converted into a complex in such a way that the inactivation can be removed by two-photon absorption and the original property can be restored.

29. This process is also useful if certain colors are used that only initiate polymerization can if they are bound to macromolecular substrates. In this example, a gel called crystalline violet leuconitrile, a monomer,  a difunctional monomer, a mild reducing agent and Contains polymethylacrylic acid, exposed. The color produced by two-photon absorption Cation combines with the polymer. The gel then becomes a radiation in the absorption band of the color below the excitation energy exposed. The color is reduced and creates radicals, to polymerize the monomer. That way overcome the ineffectiveness of the two-photon absorption process, by a light "development" of the weak picture is used. This reinforcing effect is additional Advantage with unfocused overlap areas, or when the rays spread to a more diffuse geometry instead of being focused, thin rays. For example, when three light levels are used to match the active one Generate area, where at their intersection a single point that includes an active area.

The examples described above contain several in which the inhomogeneous product encloses inhomogeneities in the refractive index. Below are example 3, (if sodium acrylate or acrylamide for the barium Compound is substituted), Examples 5, 6, 7 and 8, Example 12 and Examples 14, 15 and 16. To this and related inhomogeneities to use the refractive index for optical purposes it is necessary to arrange and design the areas to influence according to certain rules set out below will.

The for the production of various types of optical elements usable materials can be considered in the broadest sense as photochemical active materials that differ from a state with a refractive index in at least one  different state with different refractive index by the in US-PS 40 41 476 or in the preceding parts of this Have registration mechanisms brought. In particular Cases, such as in the manufacture of apodization screens, distributions that block the passage of light are valuable.

A group of suitable materials are the glasses and crystalline ones Materials as described by Crow et al. (Applied Optics Vol. 14, March 1975, p. 580 and in the published in Applied Optics Essay series by Thaxter (April 1974, p. 913), Staebler and Phillips (April 1974, p. 788) and Micheron, Mayeux and Trotier (April 1974, p. 784). These materials include: strontium barium niobate, lithium Niobate and lead-lanthanum-titanium-zirconate ceramics (PLZT). Some These materials can also be used as described earlier be sensitized (Phillips et. al. RCA Rev. 33 (1972) p. 94; and Ishida et. al. Applied Phys. Let. Vol. 21, (1972) p. 192).

If optical elements of considerable size are needed, so plastic materials are preferred that are reliable can be made without imperfections, and what be subjected to a wide range of photochemical processes can, the differences in refractive index and permeability surrender. An important group of plastic materials is described in U.S. Patent No. 37 26 588 (J.R. Rust). The plastic materials occurring in this document can undergo photochemical changes in two different ways , one of which is an addition polymer and the other another gives a condensation polymer. These different Products have certain different refractive indices and  can be structured to the to give inhomogeneous optical components of this invention. Likewise useful material is described in US Pat. No. 3,615,454 (Cescon et. Al.).

Another useful group of materials are those photochemically from a polymerization state in transferred a different, different polymerization state can be. Materials with a complex polymer brought into simpler polymeric states by photochemical means is, for example, in US Pat. No. 2,892,712 and 38 84 696 described in which connections by light energy in the range from 170 to 400 nm. A larger group is characterized by reactions at to which light excitation creates connections instead of simpler ones To produce products; the US PS are to be mentioned here 26 10 120 and 26 70 287 (polyvinyl zinamate with light sensitizers, such as B. nitro compounds and diaminoaryl compounds), US Pat. No. 2,756,143 (benzal and tin amal arvinylacetophenone) Polymers), US Pat. No. 2,861,058 (alkali-soluble succinic acid or phthalic esters of partially esterified Polyvinyl alcohol, in which the esterifying agent is cinnamic acid or are their derivatives), the US-PS 27 02 243 (Diazo- Compounds and Polyimides), U.S. Patents 31 43 416 and 31 43 417 (Diazo compounds and special polyamides), US Pat. No. 3,189,451 (Aldehydes and a diazo compound of an arylamine), and US Pat. No. 2,927,022 (cellulose derivatives and an ethylene Compound as addition-polymerization compound). The Materials compiled in this paragraph can by the practical application of this invention can be brought that they are controlled by conversion from a monomer to a polymer or from polymers to addition and crosslinked Transforming polymers through condensation,  Addition or networking in a controlled and in areas expiring way happens.

An important group of materials has been found in the literature described to record space holograms, and some these materials are commercially available, e.g. B. from the DuPont Corporation, Newport Research Corporation, the Hughes Aircraft Corporation and others. Accessible technical Information regarding some of these materials shows that they often lead to a widely different refractive index Are capable of change and that they are particularly useful when significant refractive index change is required. (See also table 12).

A group of such holographic material was developed by Chambers and Jenney (U.S. Patent No. 44 79 185, J. Opt. Soc. Am. Vol. 60, 1970, p. 1155 and vol. 61, 1971, p. 1116). These materials are liquid at first and shrink on exposure. they can be used in protective cells for the present purposes and just like other materials related undergo volume changes with use in this invention, it may be necessary to grind and polish them after the internal refraction inhomogeneities are generated. If such materials are used, they are subsequent molding and finishing operations part the invention.

An example of another group of materials is that in an essay by Tomlinson, Chrandross and others in Appl. Opt., Vol. 15, Feb. 1976, p. 534 and in U.S. Patent No. 38 09 732 described photopolymer systems made up of many components, where photochemical processes change the chemical  Composition with very high differences in the refractive index cause. The mechanisms that make up these differences have not yet been elucidated, but are obvious the materials can be used to make effective light guides to create within a volume that is analogous to fiber optics are by the methods described in this invention is produced. Optical inhomogeneities in considerable Volumes can be created if the diffusion requirements of the materials will be charged and if the individual Components selectively with appropriate radiation mechanisms that are different in a different way than the respective polymerization rate (as of Chandross and Tomlinson described).

Other materials that cause gradation in the refractive index J. D. Margerum in his final Report of July 1973 "Chemistry of Photopolymer Light Sensitive Systems "described as Report No. AD770068 is available from the Air Force Office of Scientific Research. The one by M. J. Bowden and others in Appl. Optics Vol. 13, No. 1, Jan. 1974, p. 112, specially prepared polymethyl methacrylate has the disadvantage that changing the Refractive index is delayed, but can still occur in some Cases are used. This material was created by Tomlinson and Chandross and others used optical waveguides to form by a focused beam of light and usual photochemistry can be used (US-PS 36 89 264 and 38 09 686), similar to that described in US Pat. No. 4,041,476 is.

Other media for recording holography with considerable Ability to change the refractive index are in the US PS 35 47 509 (R.G. Brandes), 39 26 637 (Bartolini and Bloom),  and by Booth in Appl. Opt. Vol. 11, No. 12, 1973, p. 2994. That of Bartolini and Material described by Bloom is particularly interesting because of a Amount of castable polymeric matrix substances can be used can to accommodate the photoactive diketones and elements of considerable size can be easily manufactured. additional such material is in US-PS 37 07 371 (files) and by D. S. Lo (Appl. Opt., Vol. 13, No. 4, April 1974, p. 861) and S. Maslowski (Appl. Opt., Vol. 13, No. 4, April 1974, p. 857) described. The material of files consists of a color Styrene-peroxide combination, Lo uses a salicylide eneaniline and Maslowski uses a spyropyran derivative. Others for recording Hologram serving materials have been developed by M. R. B. Forshaw in Optics and Laser Technology, Feb. 1974, pp. 28 and by Bowden u. a. in Polymer Engineering and Science, July 1974, 14, p. 494.

Of considerable value when building computer memories and of active optical switching systems are those of R. L. Fork u. a. in app. Phys. Lett., Vol. 20 of February 1972, p. 139 and from Kogelnik and Shank (Appl. Phys. Lett. Vol. 18, Feb. 1971, p. 152) described materials. Storage elements, those such excited materials Advantage over simple fluorescence systems that Emission direction by the direction of the exciting radiation can be determined. This allows increased effectiveness, if the memory is used in "channel" mode, and it results in better selectivity when reading the bits. Mentioned are also auxiliary materials and the fixation technique, whereby after the formation of a distribution with a changed refractive index the material for such wavelengths used in the construction were made insensitive. An example  such mechanisms using aci anions can be found in the US-PS 35 31 281 and 35 31 282 can be found.

It should be remembered that for some applications, e.g. B. with correction plates, the size range of the refractive index change doesn't need to be very big. For example very small differences in powerful instruments useful at where the rays are at a small angle, e.g. B. with lenses with a long focal length, converge. Bigger differences at the second and third decimal place are necessary for instruments with less refractive power, where the Incident rays at large angles.

A useful example in the middle range was calculated by Sinai. This example concerned a particular plano-convex Lens and showed that  the biggest necessary change in the refractive index only Is 0.0014. This change is far in the range of the available achievable changes (Table 12).

Further examples can be found in the following sections, and in Table 9 there are various combinations of the focal length (f), the refractive index range N ₁ with the index differences ( Δ N) for different values of the lens radii (r) for a basic refractive index of N ₀ = 1,450 compiled. It should be noted that focal lengths are present in each individual compilation which require a change in the refractive index of less than 0.07.

Correction for chromatic aberrations in optical systems is achieved primarily through the use of apochromats, where the focal points are two or three different wavelengths correspond, must coincide with what the primary Residual chromatic aberration is corrected. To this Unfortunately, it is necessary to reach the goal resort to large amounts of curvature from refractive surfaces, causing geometric aberrations again high order in the case of spherical lenses. Hence this draws the disadvantage of the limitation to small opening angles after itself. In the case of the lenses according to the invention with variable refractive index it becomes possible for the first time with such large amounts of curvature breaking surfaces to reconcile with corrected geometric and chromatic Aberration.

While many of the useful optical elements of the invention those with controlled distribution of change in Are refractive index, contain some elements, and special  those corrected for refractive errors different permeability distributions. A bifunctional Monomer such as B. divinylbenzene, which in is a system that consists of a frozen Glass made of monomeric styrene in a Pyrex cell, other monomers, such as. B. p-isopropylstyrene or chlorine-substituted styrene derivatives such a different permeability can be used. There can also be intersecting beams of electromagnetic radiation Radiation including x-rays and gamma rays used in glass or plastic to make such less permeable spots in what is known as the apodization screen cause optical element. Correct such screens Defects resulting from diffraction. An aperture that the angular opening of the effective beam at the Limited entrance pupil, creates diffraction rings around the true one Point that is the image of a point. They say that Diffraction pattern containing a mean or principal maximum, in which most of the light energy is concentrated in, and subsidiary or secondary maxima at which the light energy is considerably lower. A diffraction error becomes obvious if an optical image with two neighboring ones Images with a large difference in brightness is generated: The Image of the weaker element tends to deal with the diffraction rings of the lighter element to mix, and in addition tend the subsidiary intensities of the diffraction pattern the contrasts of the images of distant objects to reduce.

The distributed opacities that are generated by the apodization screens according to the invention allow the subsidiary intensities or secondary maxima to be reduced by modifying the distribution of the amplitude of the light vibrations in the opening plane by continuously changing permeability. This permeability is distributed before the opening of the entrance pupil and changes continuously from one point to another, it is a function F (x, y) of each point of the screen. Such umbrellas generally have a permeability that decreases from the central axis to the outside areas. Conversely, in a related application, the opposite distribution is used to form a screen that sharpens the center diffraction point and thus increases the resolving power of the optical system with respect to point sources. An important application of apodized optical components is in the field of laser optics and especially in the laser components that are used in the energy systems for fusions using laser optics.

The invention is described below, for example, with the aid of Drawing described; in this shows:

Fig. 1, the axial forming an optical element having symmetry properties,

Fig. 2, the spherical shape of a member having symmetry properties,

Fig. 3, the cylindrical shape of an element having symmetry properties,

FIGS. 4 and 5 are each a member having a specific property change,

Fig. 6 is an element having intrinsic features,

Fig. 7 is a prism with optical inhomogeneity in time instead of in spatial terms,

Fig. 8 is a single lens having a spherical correction, using a higher refractive index in the central region than at the outer edges

Fig. 9 is a spherically corrected single lens with low refractive index in the central region,

Fig. 10 shows the classic inhomogeneous "Wood's lens"

Fig. 11 is a simple device for generating an inhomogeneous lenses with radial gradient distribution,

Fig. 12 shows the path of an axial light beam in a "Wood's lens", which is partially corrected spherical,

FIG. 13 is a single lens having a planar index distribution; Areas with the same index value are planes perpendicular to the optical axis,

Fig. 14 is a single lens having a radial gradient of the type as used in the generalized "Wood's lens"

Fig. 15, a complex optical element which shows a corresponding one cemented doublet telescopic aplanatic lens,

Fig. 16 shows a refractive index distribution that was created by a not of this invention, appropriate means,

Wherein this modification, a part of the invention and is described in Example 37. Fig. 17 shows a refractive index distribution with RadialGradient that was generated by modification of the example 36,

Fig. 18 is an automated system that inhomogeneous for real-time verification and generation optics according to this invention is capable of

Fig. 19 is an f / 6.3 Einze 75673 00070 552 00004 001000280000000200012000285917556200040 0002002633036 75554llinse of cylindrical refractive index distribution,

Fig. 20 is an analog according to the invention constructed inside a light fiber optics,

Fig. 21 is a plot of two-photon processes under use of ruby and Nd-YAG lasers with systems by class I, Group 3,

Fig. 22 is a plot of two-photon processes with use of argon and ruby lasers in systems of the class I, group 3, in which the laser with low intensity is tuned through a range of wavelengths,

Fig. 23 is an application of this invention for computing purposes.

The distributions of the refractive index obtained by applying this Invention can be achieved according to three properties be classified: 1. symmetry properties, 2. Type of property changes and 3. Limit properties. Each of these groups can be further divided.

Fig. 1 shows the axial shape of an element with symmetry properties. Such an axial gradient exists where the gradient is always parallel to the optical axis. The areas of constant refractive indices are planes perpendicular to the axis. In Fig. 1, the dashed lines indicate levels of constant index within a plan-plan element, and the index function has the following polynomial form:

N (X) = N ₀ + N ₁ X + N ₂ X ² + N ₃ X ³. . .,

where N ₀, N ₁, N ₂. . . Are constants and X is the distance from a surface.

Fig. 2 shows the spherical shape of an element with symmetry properties. The index here becomes a function of the vertical distance from the surface or a function of the radial distance from the center of curvature; the areas with constant refractive index are spherical areas. The form of the index function in this case is:

N (r) = N ₀ + N ₁ r ² + N ₂ r ⁴ + N ₃ r ⁶. . .,

where N ₀, N ₁, N ₂. . . Are constant, and r is the radial distance from the center of curvature.

Fig. 3 shows a cylindrical shape of an element with symmetry properties. Cylindrical distributions result from a continuous index change in a direction perpendicular to the optical axis. The areas of constant refractive index are therefore cylinders whose axes coincide with the optical axis. Since the gradient of the refractive index is perpendicular to the optical axis, the term "radial gradient" is also used to describe a cylindrical index distribution. The form of the index function is:

N (R) = N ₀ + N ₁ R ² + N ₂ R ⁴ + N ₃ R ⁶. . .,

where N ₀, N ₁, N ₂ are constants and R is the perpendicular distance from the optical axis.

Obviously, many other symmetries can also be found in this Group with symmetry properties are presented.

FIGS. 4 and 5 show characteristics of the elements with index change Fig. 4 shows a linear axial gradient, wherein

N = 1.5 + 0.01 X

is, while Fig. 5 shows a polynomial Axialgradienten, wherein

N = 1.5 + 0.01 X ²

is.

The description is:

• a) polynomial in a variable when X is the distance along the optical axis, N = N ₀ + N ₁ X + N ₂ X ². . .
• b) polynomial in more than one variable coordinate, e.g. B. N (X ₁, R) = N ₀ + N ₁ (X) R ² + N ₂ (X) R ⁴. . .

Figure 6 shows an element with interface properties. The group with interface properties can be divided into two basic groups.

• a) Those where the interface of the inhomogeneous index distribution at the same time the interface of the material itself is
• b) those in which one or more interfaces of the inhomogeneous media are different from material interfaces themselves, e.g. As in Fig. 6, where a plane-plane element is present with a region of constant index, and two specific non-homogeneous areas. It should be noted that the interface between the areas can be flat, spherical or arbitrary.

The invention itself leads to the production of apochromatic Elements, especially because of their ability to two Areas with different refractive index in one Generate volume. The refractive index of most optical Materials change with the wavelength, and therefore are the ray paths of rays of different wavelengths different through a lens. The theory of chromatic Aberration for inhomogeneous lenses was described by P. Sands in J. Opt. Soc. Am., Vol. 61, 1971, p. 777.

It is also possible to create optical inhomogeneities as a function of time instead of that of space. FIG. 7 shows a prism made of the material described by Tomlinson, in which the refractive index is changed due to a photochromic effect. Such a prism can be used in a solid state scanner, or if the prism is turned into a lens, the same mechanism will change the focal length. The deflection of the angle B is given by the formula:

Δ Bi = d Δ N

given.  

For a value Δ N = 0.01, a deflection of 1% from the wedge angle d of the prism can be obtained. With a wedge angle of 30 ° and a change in the refractive index of 0.01, the deflection is approximately ½ °. Fig. 8 shows a single lens in which the spherical aberration has been corrected by raising the refractive index of the original cast or ground lines so that it has a gradient toward the center of the lens (regions with the same refractive index are cylinders). The focal point of the middle rays now coincides with the focal point of the marginal rays. In Fig. 9 the reverse process is shown where the invention was used to decrease the refractive index towards the edge, by which process the spherical aberration was corrected by the fact that the edge rays now coincide with the focal point of the center rays.

In general, radial gradients are far more effective in correcting aberrations than axial gradients, and are of greater value in lens design. An important advantage of using flat index distributions is the fact that manufacturing tolerances can be considerably reduced while still being effective. The radial distribution is most effective when changing the refractive power of a shaped lens (changing the diopter). When calculating this radial gradient, the refractive index is developed by a series expansion of the even powers of the radial distance r from the optical axis in a cylindrical coordinate system:

N (r) = N ₀ + N ₁ r ² +. . ..

Then is t the thickness of the lens, then the refractive power of the lens is changed by the amount -2 N ₁ t . For example, with a spectacle lens of 40 mm in diameter and 5 mm in thickness, a radial index gradient of N ₁ = -0.000025 results in a change in refractive power of +1.00 diopter. A refractive index change of just 0.01 over the entire surface of the lens is necessary. Table 1 shows an example of this relationship between refractive power and opening. An important application of the invention lies in the possibility of greatly reducing the required stock of spectacle lenses of different refractive powers by converting the blanks into glasses of the desired refractive power and even introducing bifocal properties through locally changing refractive index.

The classic inhomogeneous optical element is the first in the Book by R. W. Wood "Physical Optics" described so-called "Wood's lens". This Wood lens consists of a plane-parallel, plate-shaped optical element, in which the refractive index changes outwards from the optical axis. A larger refractive index on the optical axis compared to the border areas results in a convergent lens, while the reverse property gives a divergent lens.

With such a lens, the condition is that an image is formed can

N (R) = N ₀ + N ₁ R ²,

where R is the vertical distance from the optical axis (rotational symmetry axis). If the thickness of the plate is t and

is much smaller than 1, then the focal length is one such lens

More general equations for the focal length f and the back focal length Bf for a Wood lens are:

A representation of a Wood lens can be found in Fig. 10, and the panels 2 and 9 give values for different combinations of focal lengths, N ₁ and thicknesses.

Although in the preferred form of this invention the required changes in energy levels are brought about by the combined action of at least two intersecting light beams to create the internal arrangement for optical inhomogeneity, the classic Wood's lens of this example (and the optical elements which can also be applied to the production of corrective plates of irregular shape or of Schmidt-plates are in Fig. 3, 8, 9 and 14) effectively prepared by a modified method.

In a variation of this alternative technique, what is to become Wood's lens is placed in an apparatus as shown in Fig. 11. On the left is a source of actinic radiation, in the middle a diaphragm that can be closed completely to block the actinic radiation completely and that can be opened continuously in the form of a growing circle from the center outwards to the interfaces of the optical element to be formed , and the workpiece is displayed on the right.

This workpiece is usually a cell made up of two flat glass or quartz glass plates, depending on the actinic Radiation that is used. Building a suitable one Cell is described in Example 1 of US Pat. No. 3,732,097, the distance can be changed as required.

The operation of this modified device depends on the special composition of the medium Energy transmission means, such as B. a stable fluorescence contains, as it had previously in a similar function was discussed. It should be noted that the change now described for its simplicity and utility is very important if otherwise intersecting Beams are required to have special inner boundaries and similar inhomogeneous optical elements according to this invention to manufacture. This method offers a superior way to previously known inhomogeneous optical Elements to arrive that were previously only through the lengthy  Ion exchange method or the Sinai method can be obtained could.

To take advantage of this modified method over the known The following example will clarify the state of the art 31, which does not refer to the examples of the invention belongs. Example 32 is a modified form of Example 31 and is an example of the invention.

31. No example of the present invention.

• . 1. In an arrangement according to Figure 11, the cell is filled in the dark room with the following, being set at 40 ° C Solution: Gelatine15% Acrylamid5% Dimedon1,6 x 10 ^- ³ mol Thionin4,0 × 10 ^- ⁵ mol Water to make 100%,
  adjusted pH value 5.7.
• 2. Cool until there is a light blue, clear gelatin slab has formed in the cell.
• 3. Close the cover, switch on the red light source, and the side of the cell facing the light source via a Expose for 10 to 20 minutes while exposing the aperture is opened continuously so that at the end of the Exposure time is fully open. Lock cell, to prevent drainage of the gel.

Fig. 16 shows the result of the experiment in a side sectional view of the cell. An approximately conical area of colorless polymer-copolymer material has formed, which is surrounded on all sides except for an area of unpolymerized material which is still light blue in color. The process was also handled mathematically by Tomlinson, Appl. Opt. Vol. 11, April 1971. In simple terms, the process is such that the absorption on the front of the cell, which causes polymerization, reduces the level of radiation on the rear so that the polymerization limit advances as indicated. This effect is least evident in photo reactions with increasing transparency; it is most evident when the transparency remains or increases.

32. Step 1 of Example 31 is repeated, but will the solution a small amount of one of those previously discussed Energy transfer agent added. If e.g. B. the energy transfer medium is a fluorescent, then you become it choose from the water-soluble fluorescent agents to get the to meet the following requirements.

• 1. The fluorescence is caused by light from such a wavelength range activated, which is not the same as that is absorbed by the activating color and activates it. For example, in the case of thionine, one becomes a fluorescent use that by blue light of about 450 nm or by Ultraviolet is activated.
• 2. The fluorescence emission should be in a range for which is sensitive to the color to be activated and in which it is activated. For example, in the case of thionine the fluorescence be in red.
• 3. The fluorescent should not activate the polymerization itself.

Another difference from example 31 is the red one Light source from a high intensity source of blue or ultraviolet light. In the case of the example 31, the light intensity and the irradiation time were easier Way connected with the depth of penetration. In the present The case is the provision of an intense light source important for the success of the invention. The intensity of the Light source should be so large that a large excess compared to the number of photons per cm³ in the medium the number of molecules of the absorbent energy transfer agent.

The exposure is carried out as described in Example 31, but an entirely different result is achieved, as shown in FIG. 17. In this case the desired radially directed gradient is obtained and a true Wood lens is created in the cell.

The explanation for this difference is simply that the large excess of photons over the entire strength of the cell approximately from the front to the back the same supply of photons at the fluorescent results. It follows that along the entire light path from the Front to back approximately equal numbers of fluorescent molecules activating approximately equal numbers generate red photons, which in turn are approximately the same Amounts of a red-absorbing blue catalyst for the Activate polymerization. An improved resolution (smaller free path length for the red fluorescence photons before Capture) can be done by increasing the amount of energy transfer medium be achieved.  

The process described above for making the very Desired inhomogeneous optical elements can simply be one Variety of different energy transfer agents or catalysts be adjusted if the three requirements discussed above get noticed. It is obvious that at Presence of other components in the volume, e.g. B. acid anions delivered components to the generated item fix the wavelengths and the absorbent so must be selected that such acid anions or others Components are not activated unintentionally.

While the automated device with feedback to Fig. 18, which will be described later in detail, is ideally suited to prepare highly specific inhomogeneous optical elements in this manner, it is also possible to obtain approximately the desired properties in some cases in a satisfactory manner by calculated amounts of radiation can be used with carefully composed preparations. It should be noted that although light radiation sources are generally used, it is also possible to use materials which transmit energy when using ionizing radiation as excitation energy. Such materials have been compiled by Sangster and Irvine in J. of Chem. Phys., Vol. 24, 1956, p. 670. An obvious advantage of such materials is that they do not have to be fixed by a separate process in order to prevent unwanted activation by light radiation which passes through them during their use as an optical element, but are simply to be protected from the special ionization radiation. As in the case of the light-activated materials, the variation of the activating radiation over the surface of the optical element can be achieved by using a time-controlled exposure as described above, or an attenuator for the radiation can be produced in which the attenuation profile is calculated is determined as a function of the radiation law which is to be used to obtain the continuous change in the refractive index after the distance from the axis (in the case of the inhomogeneous optical elements with rotational symmetry about the axis).

Even when using the device with feedback it will often be advantageous by calculating approximate behavior of the medium under the special radiation flow conditions to determine. With a rotationally symmetrical element, with to which the spherical aberration is to be corrected this means that the index correction to be carried out at every point the lens is calculated as a function of the center distance, and that also the radiation flux is calculated, which at each the points must arrive in order to get the desired correction. An example of such a calculation is in example 37 given.

² is replaced mol ^- 33. The mixing procedure to step 1 in Example 31 wherein the thionin by eosin Y at a concentration of 10 is repeated. To generate the structured optical inhomogeneity, two intersecting laser beams with corresponding energy properties (see Table 10) can be selected using the mechanisms of class I group 3, or combinations of lasers with fixed and with tunable wavelength according to the rules that were discussed in the mechanisms of class II group 2.

Unlike the method of Example 32, these allow  controlled systems both an internal limit function structure a radial index distribution.

34. Two solutions A and B are prepared as follows:

• A. 14 g polyacrylamide, 2.38 g sodium p-toluenesulfinate dihydrate, 10 ^-2 mol eosin Y in 100 ml water. Heat with stirring at 60 to 80 ° C until the mixture is clear blue, viscous and free of bubbles.
• B. 50 percent by weight sodium acrylate.

In the dark room two parts of solution A become two Parts of solution B mixed and half a part of the room 37% formaldehyde solution acidified with acrylic acid added. The cell is filled as in Example 31 and how exposed in Example 33. After exposure you get one tough, transparent gel with structured optical inhomogeneity, which is completely fixed and no longer sensitive to light is.

35. In the dark room, a cell prepared as in Example 1, using sodium m-Nitrophenylazetat with a minimum concentration of 10 ^- ² mol in 100 ml water, 20% acrylamide, 0.5% methylene-bis-acrylamide and enough gelatin for solidification. Exposure as in Figure 33 gives a similar product. The acetate can also be replaced by eosin Y and dimidol or p-toluenesulfinate.

While it is not difficult to change the optical behavior of the Wood's lens to control that of a simple convex Single lens or symmetrical aspherical devices equivalent  by operating the cover as described above controls by time, or how easy it is, simple rotational symmetries in optical elements through regular Movement of the focal point or the beam intersection to produce in relation to the medium body become more complex optical elements preferably using a Prepared device, the computer-controlled exposure allowed. Combinations of are preferably used for this purpose Media with little or no time delay react to the radiation states, and after that Reaction remain stable, used and that's what happens together with an automatic feedback control (e.g. simultaneous monitoring and inhomogeneity generation), but it is also possible to use materials that follow Aging or physical transformation is required undergo (e.g. the Jenny materials) at those after generation of inhomogeneities and aging the optical element in the final state by customary surface design and polishing can be brought.

Many test systems for optically inhomogeneous materials appear in the literature and can simply be for the one you want Control feedback process can be modified. A first one An example is the control feedback system, as in the US-PS 35 87 195 under the title "Optical Surface Generating Method and Apparatus "has appeared, this application is briefly described in US-PS 36 58 528. Although these Apparatus was designed to match the surface design of an optical element to be monitored and directed for the present slightly different purpose applicable. Other surveillance techniques with the manufacturing device the US-PS 38 29 838 can be connected  and are useful for the purpose described here by Wyant, O'Neill and MacGovern in Appl. Opt. Vol. 13, 1974, P. 1549 and also described by Nadov (op. Cit. P. 1551). Further useful systems were developed by Tomlinson and Aumiller in Appl. Opt. Vol. 14, 1975, p. 1100 and by Hunter and Schreiber Appl. Opt. Vol. 14, 1975, p. 25. Another one System is developed by Brodnar and Ratajczyk in Appl. Opt. Vol. 4, 1965, p. 181. Another technique that is a holography with double exposure is used by Küpper and van Dÿk in Rev.Sci.Instr. 43, 1972, p. 1492.

The combination of the test systems described in the previous approach with suitable devices for beam control, as in the U.S. Patent 3,658,528 is described, or other control systems is a trivial task for professionals in the field of Elementary optics and electronic control. The following short Description sets out the basic elements of such a system for control, feedback and structuring.

In Fig. 18 a volume of a medium 1 is displayed, the radiation-induced states of energy level change can run as they are shown as a combined effect of the two laser beams 3 and 4 at the spot 2. The lasers are equipped with beam intensity control and deflection devices 5 and 6 , which can be constructed in many different ways (see US Pat. No. 3,829,838, where construction and operating details can be found). 7 is a pattern generator and 8 is a receiving device which can input signals received in digital form to a computer 9 which also contains information relating to the desired optical property of the volume 1 .

The computer 9 controls the control and deflection devices 5 and 6 in the correct manner, either directly or through additional computer and control functions, in order to produce the properties of the optical element in the desired manner (for details on the computer parts, see the patent mentioned above) .

36. The image created by a "Wood's lens" is not free from image errors. In order to produce an axial image free from third order spherical aberrations, the coefficient of the next expression N ₂ for N (R) is required so that:

N (R) = N ₀- N ₁ R ²- N ₂ R ⁴.

If the fifth order of the spherical deviation is to be corrected, a coefficient N ₃ is necessary and the expression is:

N (R) = N ₀- N ₁ R ²- N ₂ R ⁴- N ₃ R ⁶.

FIG. 19 shows a "generalized Wood lens" with a light beam that travels from an axial object point to an axial image point. D. Moore describes in J. Opt. Soc. At the. Vol. 61, 1971, p. 886 the index distribution for such a lens. These data appear here as Table 3 and receive the results of a calculation of N ₁ and N ₂ in such a way that the system has the prescribed back focal length and the spherical aberration of the third order is corrected. The special value of the optical elements with a radial gradient of inhomogeneity is denoted by the size of N ₁: It is very easy to produce a generalized "Wood's lens" with a back focal length of 10 cm and a radius of 2 cm.

In this case there are coma, astigmatism, curvature and Distortion not corrected. The fact that in this "generalized" Wood's lens the spherical aberration the third order has been reduced practically to zero, is particularly important and can be done with a normal lens, the curvature of a minimal spherical aberration adjusted, cannot be achieved.

37. D. Moore has calculated in J. Opt. Soc. At the. Vol. 61, 1971, pp. 886 to 894 the effect of a planar index distribution shown on controlling the aberration. It turned out that the contribution of an inhomogeneous surface is most effective contributes to the control of spherical aberration and therefore has the same effect as an aspherical surface. It also emerges that the contribution of the passage is small and therefore a change in strength is only slight Consequences in correcting third order aberrations.

It is well known that if there is astigmatism and Petzval curvature in a lens, there is a stopping point for which the disturbance is zero. Using a flat index distribution, two spherical surfaces and a stop, it is possible to correct the third-order spherical aberration, the coma and the image deviation. Fig. 13 shows such a lens, panel 4 gives the design data.

A corrected lens of this type can be made using the device of FIG. 17 using an energy transfer medium as described in Example 32. However, if the device with feedback according to FIG. 18 is not used, the possible accuracy due to deviations in the composition is the same. not exactly the biggest. With careful control, however, such an approximation may be useful for non-critical optical components. The following calculations are used to determine the basic requirements for medium and radiation quality.

A. Calculation assuming an external radiation state and an inner one, through an energy transfer medium transmitted radiation state.

For a simple case it is assumed that the surplus of photons over the number of energy-transferring molecules in the medium is at least 100: 1 per cm³ of the medium volume, that the maximum thickness of the medium is a few millimeters and that the energy transfer has the effect that Polymerization and then increasing the refractive index the refractive index is an increasing function of the above received radiation.

This function can generally be represented by the following formula are expressed:

n = n _i + b Φ (23)

where n _{i is} the initial refractive index of the medium before the start of radiation, Φ is the total amount of radiation absorbed at a distance h from the axis, and b is a constant.

The expression:

describes the principle spherical aberration of a thin lens, where r is the lens radius , f is the focal length and A is a constant. By comparing this expression with the change in focal length resulting from a change in the convergence of the lens from the center to the edge, we get the formula:

We now turn to the classic optical relationship, which is the relative index change with the relative focal length change connects and is written:

and compare these two formulas (25) and (26), then get we:

where A is a constant and the formula expresses the change in refractive index that can be achieved at point M of the lens, which is h away from the axis, to force a focal length variation that corrects for the principal spherical aberration resulting from that point .

A comparison of equations (23) and (27) above shows the further calculation formula:

Δ n = n - n ₀ = - ah ² = n _i + b ₀- n ₀,

where n ₀ is the refractive index on the axis, where h = 0, n = n ₀, Φ = Φ ₀, and Φ is the total amount of radiation obtained on the axis, and therefore:

0 = n _i + b Φ ₀- n ₀

and

B. calculation assuming external radiation states, that work together within the medium.

In this mode, the important relationships are similar those previously described, except that here the structure is in discrete Depths can be affected, which causes one Can attach interfaces controlled. It is with this type necessary, the overlap size and quantum yield factors note that are similar for other types of structures, but are described here so that they apply to the case with inhomogeneities in the refractive index of direct processes come from. Then there is a direct connection between the polymerization (and therefore the increase in the refractive index) and the decline from an excited state before achieved by an excitation process of at least two steps has been.

With this type of construction, the overlap of the radiation states only a short time with a section of the structured optical inhomogeneity coincide. In this case the degree of polymerization is a function of the efficiency of the Free radical polymerization, which in turn is a Function of the effectiveness of the reaction process will be that caused by the decay of the last excited state of the structuring process will be excited. All of this works best  related to each other, and the final Production of optical inhomogeneities in a given The area of the medium then becomes a function of the following Be expressive:

where N is the density of the excitable molecular type, V is the volume of the beam intersection, I ₁₂ and I ₂₃ are the average beam intensities, B ₁₂ and B ₂₃ are the Einstein absorption coefficients for transitions between a first and a second excited state, or of a second to a third excited state, each by hv ₁ or hv ₂, and η ₃₁ is the quantum yield of the polymerization per transition from the third excited state to the lowest state, M is the number of R times per second addressed locations and has been assumed that at each of the R times at which a location was addressed, a pumping operation was initiated by a single pair of time-separated pulses which occurred in the order hv ₁ followed by hv ₂ so that the time from the beginning of the hv ₁ pulse at the end of the hv ₂ pulse is much shorter than the lifespan of the second excitation state. It is obvious that, in order to achieve maximum effect, it is desirable to make the expression B ₁₂ · B ₂₃ · η ₃₁ as large as possible.

38. While the benefit of a radial gradient distribution that replaced the aspherical curvature was shown in Example 30, the radial gradient shown in FIG. 14 is used in the present case, namely in a single lens with a radial gradient of the type like it was used in the generalized Wood lens:

N (R) = N ₀ + N ₁ R ² + N ₂ R ⁴.

In this case, the construction data are given in Table 5. It can be seen that three aberrations (the spherical, the coma and the astigmatism) were corrected by an appropriate choice of the curvatures, the strengths and the values from N ₁ to N ₂, while the distortion was corrected by changing the stop. Petzval's field curvature remains uncorrected. This lens is free from all third order deviations except for the Petzval curvature.

The focal length of a single lens with a radial gradient becomes through the formula:

given, the upper expressions for N ₁ <0 and the lower ones for N ₁ <0, f the focal length, C ₀ the first surface curvature, C ₁ the second surface curvature, t the mean thickness, the function of the refractive index is the same N (R) = N ₀ + N ₁ R ² + N ₂ R ⁴ +. . ., and

For values (kt) ² «1 this equation can be approximated by

in which

is.  

39. A more complex optical element is shown in Fig. 15. Here two elements of the same thickness and with cylindrical surfaces with the same refractive index are connected to each other to create an aplanar telescope objective. While an equivalent lens could be produced by two Wood's lenses, which can be manufactured according to the GRIN or Sinai method, this telescope double lens within a single block of matter can only be produced directly by the present invention. A similar element, but with an air gap, was described by Matsumara in US Pat. No. 3,637,295 using the GRIN technique to obtain two radial gradient elements.

The two aberrations that have been corrected, the spherical Deviation and the coma. The design data for these corrected lenses are summarized in Table 6.

40. A lens with a focal length aperture ratio of f /6.3 is shown in FIG. 19. It is a single lens with a cylindrical index distribution. It has approximately the same spherical aberration, the same coma, the same tangential and arrow field curvatures as a homogeneous single photographic lens with the ratio f / 11. The half field angle is 25 °, the overall aberrations are larger than from the third order. This lens has a refractive index difference of -0.008 between the center and the periphery of the lens. Table 7 gives the design data of this lens. A second lens with f / 11, the overall aberrations of which were largely reduced compared to a homogeneous single photographic lens f / 11, is listed in Table 8.

Various attempts have been made to: Possibility to explore a volume calculator storage to train. One of these attempts used holography and was originally developed by van Heerden in Appl.Opt. Vol. 2, 1963, p. 393. The information is as an inter Reference pattern saved that extends through the entire volume of a room hologram. In such an attempt control of the attachment is not possible and information Mation coding does not take place in it (e.g. the gradations develop in optical density or in refractive index through randomly placed patterns of interference rings, the information being read out with coherent light by interacting with the entire stock of stored Wrestling is reawakened). Such a memory is "pages organized "and from the outset for the exchange of information badly suited with a digital computer.

Some researchers have used three-dimensional storage systems wrote in areas with special composition be created within the volume of a storage content, where each bit is a positive or negative information Bit according to its state and location represents. Two researchers used thermal effects to write bits into volume storage, e.g. B. is in the U.S. Patent No. 37 15 734 developed a process to carbon areas in a three-dimensional arrangement of plastic, and an improved system according to US-PS 38 20 087 be uses melted areas of crystalline material around to represent negative bit that is incapable of harmonic Generation is and results in increased selectivity.

A number of researchers have described systems which easy access to two-photon absorption processes  take advantage of, as in our classification system according to class I group 2 and 3 are present, but they have the value of this before for the selective activation of real photochemical Conversions not recognized. Instead, the Ener used to feed a material into an excited feed to place a condition that is artificially above a certain Time can be maintained. This excited state condition of electrons in a crystalline matrix not resistant (see e.g. US-PS 34 66 616, 36 54 626 and 39 40 748), so that the memory is both below normal Light and temperature conditions as well as when reading out is constant. The US-PS 35 08 208 (Duguay and Rentzepis), at of fluorescent materials (anthracene, pyrene and 3,4-benzopyrene) are frozen to programmed bits to keep in the excited state before emitting radiation and then by detecting the emitted fluorescence Reading return to the basic state shows a clear Difference from the present invention, in which they are the same Materials are used in a completely different way.

Following the procedure of Duguay and Rentzepis, a bigger one Volume of a material, such as B. Anthracene as a bipolar Spei chermatrix, where the two states are the ground state and are an excited state. After the reading process (in Absence of a special reprogramming by return coupling) the material is again a homogeneous volume of anthracene in the ground state. In the present invention is programmed in that the anthracene molecules between the two stable ground states of the monomers and the dimers using Class I or Class II systems switch,  as described earlier (see the examples 18 to 24 and 26 to 28). Note that the same transitions are used other two-photon systems described here these materials have certain, of each other other different properties, such as B. the ability to fluoresce or lack of ability. In this way can you e.g. B. determine the type of a programmed bit, by bringing it into radiation states that are in the program mated bit cause fluorescence reactions, however do not with the non-programmed bit. It should be noted that in this case there is no prolongation of the excited state is necessary, and that after reading the fluorescent bit returns to a stable ground state that differs from that other stable ground state of the molecule before programming ren differentiates.

It should be noted that these new systems use one a whole range of new storage materials are allowed instead of the special ones len crystalline materials or cryogenic methods the state of the art. Virtually any photochemical conversion at selected locations required for bit storage bring differences in absorption behavior to this program points highlighted by the in US Pat. No. 3,715,734, 36 54 626 or 39 40 748 described facilities are detected can (see also the report by Geller and Taylor "Three-Dimensional Information Storage in Alkali Halides by Two-Photo-Absorption "of Jan. 4, 1971, which is numbered NELC / TR 1749 available from the Naval Electronics Laboratory Center is). Similarly, bit elements created by excited emission and are distinguished by fluorescence, advantageously with the detection system as described in US-PS 35 08 208  is, or similar, read. Different from crystalline ones Materials can be any perfect storage matrices Size can be made with amorphous plastic materials, with highly qualified optical properties.

Probably the greatest advantage of the storage systems presented here lies in the possibility of using very fast electronic transition processes, such as absorption and internal conversion (between 10 ^-9 and 10 ^-15 sec), instead of the relatively slow mechanisms of fluorescence emission or the like (10 ^{- 5} to 10 ^-9 sec). Many photo chromic processes are also very fast. To learn more about these processes and their application, see the early report by Lewis C. Clapp, available from Sylvania Corporation, entitled "High Speed Optical Computers and Quantum Transition Memory Devices". These and similar schemes (US Pat. No. 3,341,825) have been expanded from the two-dimensional mode of operation to a three-dimensional space storage system by the method of this invention. The same can be said of other two-dimensional storage systems that are based on photochemical transitions, such as. B. by Maslowski in Appl. Opt. Vol. 13, 1974, p. 857, which produce opaque stains which are produced by the process according to US Pat. No. 3,715,734, e.g. B. can be detected. Likewise, in a previous section of this application, a method for producing "fiber optics generated in place" was shown. There is a large number of optical computer schemes in the literature which use fiber optic methods to be carried out by hand. It is obvious that using combinations of radiation states and memory matrix combinations, it is possible to build such integrated systems only by means of optical devices and to expand them to the methods of three-dimensional volume storage. (See Burt et. Al. In Apl. Opt. Vol. 12, 1973, p. 1213.)

Although the bits themselves are preferably stored, be there is also the possibility of the reason according to the invention were to generate a holographic volume memory to use.

An important aspect of the effectiveness of some designs, at where light emission takes place or light guidance is required to place radiation in memory are different Devices for determining and controlling vectors. To the Example it is through optical isolation of areas in where fluorescence occurs, these areas can be separated to handle and parallel operations in different parts of the memory. As a general expression for Devices for the optical isolation of sections of a three-dimensional volume, the word "hodoscopy" is used; there are many different types, e.g. B. the instruments by Hinterberger and Winston in Rev. Sci. Inst. March 1968 P. 419 or Gottschalk (Rev. Sci. Inst. Jan. 1969, p. 22) or the analogies of the scintography method as it is by Schmitz and Feuerhake (in Phys. Med. Biol. Vol. 15, 1970, p. 649 to 656) has been described, including useful mathematical Treatment procedures are listed.

Ability to be mentioned on the spot should also be mentioned generated fiber optics, selected distribution or sub Division of memory by direction (where it leads)  and by filtering out certain wavelengths (which they can forward). The optical isolation Adaptable facilities are developed by M. Oda in the Book "Small Rocket Instrumentation Technology" published in North-Holland Verlag, Amsterdam in 1966, p. 176 ff. and by the same author in Appl. Opt. Vol. 4, 1965, p. 143 be wrote.

Another method of dividing memory that can be used alone or in connection with the above is the temporal rather than the spatial division. Modern electronic methods allow millions of events per second to be checked individually over time and to be distinguished from one another. For example, Keene and others in Rev. Sci. Instr. Vol. 40, No. 9, 1969, p. 1199 examples of such a device. In another article, Yuan and Post use fast electronic methods to localize an emission result in space, whereby the device can be adapted to a location determination according to the coordinates x , y and z (see Rev. Sci. Instr. Vol. 23, No. 10, 1952, p. 553 and Jones, J. Scientific Instr. Vol. 37, 1960, pp. 318 to 323).

Above, the filtering ability was generated on the spot Waveguides mentioned, and a variety of other properties Integrated optical systems can advantageously be invented Executions according to the invention may be included. Basic To Marcatelli in Bell Syst. Techn. J. Vol. 48, pp. 2071 ff. And von Goell, in Bell Syst. Techn. J. 48, p. 2133. Filters, directional couplers and even laser devices (see the previous example with Polymethol colors) can be prepared. While the  Use individually controlled (directed or converted, e.g. B.) Radiation states of a beam in space common preferred means for bringing about the invention of changes in energy level are said to be still holographic Patterns, e.g. B. point arrangements in one or more levels, that are projected from a hologram lens as an alternative be mentioned. Such projected real holographic Images as means, three-dimensional patterns of physio-chemical Bringing nature in was first introduced by Swainson in his Dani described patent application of July 12, 1967, and this The process is part of US-PA 1 65 042. In some versions, who use intersecting beams of focused radiation, such holographic patterns can be of particular value e.g. B. in that they can simultaneously provide rays, which have multiple foci with high energy.

As in the other applications of the present invention, e.g. B. three-dimensional color sample images, lightfast pattern illustration for manufacturing purposes, structures with variable Refractive index u. a., it will often be possible from known One-photon absorption data go out when storage systems be designed. A useful collection of data, Change one-photon energy requirements of a large group materials, was developed by Tufte and Chen in IEEE Spectrum, Vol. 10, 1973, p. 26. This literature place and the cited therein result for the purposes of Er Find useful information about both changeable materials alien, as well as matrix materials, within which the former can be included according to the invention while maintaining their changeability can.

Because of the sensitivity of the instrumentation to Light emission uses a preferred embodiment of the invention  Memory structures that are read by processes that such light emission at programmed bit locations call, or the changeable properties of such Light emission z. B. in the wavelength, as a bit memory to use. Examples 20, 22, 24 and 27 describe for preferred materials for this purpose. The properties pas Transmitter materials are well described, e.g. B. that of dimers (see Tomlinson et al. in Appl. Opt. Vol. 11, 1972, p. 533) and Birks and Christophorou in Nature, vol. 197, 1963, p. 1064 and the quotes in the addendum to "Scintillation Counting", page 631 and the essay by Salmon and Chandross in Anal. Chem. Vol. 45, 1973, p. 2446, which contains valuable information about the matrix and Details of the absorption and reactivity structures of Give n-amyl anthroate. The laser properties restored Dimers are described by Fork, German and Chandross in Appl. Phys. Lett. Vol. 20, 1972, p. 139 discussed. Other particularly well-known and useful materials were found in Example 27 and mentioned in previous examples, including in particular the Isomazole (p. Example 25, and Ullman and Singh in J. Amer. Chem. Soc., Vol. 88, 1966, p. 1844, Singh et al. a. in the same Journal vol. 94, 1972, p. 1199). Similar properties light emission and stability in a plastic matrix make the materials described in US Pat. No. 3,899,687 especially interesting.

A final group of preferred materials are the indigo Color derivatives, especially the thioindigo and the Diacetylindigo materials described by Blanc and Ross in J. of Phys. Chem., Vol. 72, 1968, p. 2817 and Rogers et al. a. in J. of Amer. Chem. Soc. 79, 1957, p. 2464. These Materials were used in Examples 22 and 24 described in this application. Table 11 shows some examples of areas of one-photon reactivity  some of these materials that are not involved in converting fluorescent are effective in fluorescent forms, they show the one-photon radiation which causes fluorescence, and the emission range of fluorescence. The materials that reversible cis-trans isomeric transitions (see Table 11 and the citation of Zweig in Example 27) are for re-programmable, light-emitting memories particularly good to use. A number of useful mechanisms to effectively change the cis / trans ratio von Kan (Organic Photochemistry, pp. 20 to 23) discussed there down are the "optical pumps" and the use of Sensibi lisators that selectively add one or the other isomer bring to prevail (see also the above quote from Kan, Pp. 22 to 23).

While the preferred structuring mechanisms of the Er use light radiation are also combinations possible with other types of radiation. A large group of anorga African phosphate glasses that are exposed to shortwave radiation UV or with particle radiation become fluorescent by J. H. Schulman in an overview "Survey of Luminescence Dosimetry "in that of F.H. Attix, at US Atomic Energy Commission, Division of Technical Information at Oak Ridge, Tenn. 1967 published book "luminescence Dosimetry" be wrote. It is clearly evident that a large part of the Materials with special dosimetry from Her position of fluorescent products have been used, too to the energy equivalents of the two-photon energy with short respond to wavy ultraviolet radiation, and for that Invention can be used. Similar dosimetry materials, what changes in color or translucency were developed by A. Charlesby in "Atomic Radiation and Polymers ", Pergamon Press, N.Y., 1960, pages 101-107 described.  

While many of the materials used in the invention are bipolar, with a ground state or an excited state, for very fast storage operations it is possible to use the bipolarity of the upper level excitation states. For example, vibration cascade mechanisms operate at times on the order of 10 ^-9 to 10 ^-12 seconds and internal transition mechanisms work at times on the order of 10 ^-13 to 10 ^-14 seconds compared to fluorescence processes Need times in the order of 10 ^-5 to 10 ^-9 sec. Details are contained in the quote by Lewis C. Clapp and in US Pat. No. 3,341,825.

As with the other products of the invention structured inhomogeneity, memory can also can be operated with various of the many-photon systems. The examples are intended to explain the systems and the use a certain material is not necessarily up limits the particular class or group of an example.

Using the same rays when reading as well Storage systems are also special when it comes to writing Value due to the increased accuracy with which a bit local siert and reattached because the effect of small optical imperfections compensate for themselves when the same optics are used for different processes. If different rays or combinations of different System groups can be used on comparison bits with known arrangement can be used.

Fig. 23 shows a preferred embodiment of the invention in which the matrix is a non-crystalline, homogeneous material which can be programmed, read and re-programmed by class I or II multi-photon mechanisms. In this case, the bit information is stored in the form of a bistable material that can be switched back and forth between fluorescent and non-fluorescent states by a multi-photon absorption mechanism. Different combinations of lasers, the choice between the different systems of class I, group 3 and class II, groups 1, 2 and 3, the choice between memory properties, such as. B. color, polarization, transmission for special wavelengths, fluorescence and excited emission, the range of reversible and non-reversible storage materials - all of this literally results in thousands of combinations, which are hereby described for the first time in the basic application as described in the unique access to and controlled construction of a three-dimensional memory using multi-photon absorption mechanisms and controlled and focused radiation be described.

In the embodiment according to FIG. 23, a source of high-intensity radiation can be seen at 27 and a tunable laser light source at 25 . The memory is stored by one of the mechanisms of class I, group 3 or class II, by intersecting beams 32 and 34 at the interface 23 causing the formation of an isomer which is fluorescent, for example. The memory is read by cutting the high intensity beam with a re-tuned high energy beam that is adapted to match the two-photon absorption band for fluorescence emission. In this simple case, the photodetector 31 serves, depending on the state of the arrangement of the bit, to detect or not to detect radiation emission. For a given two-photon structure, a ruby laser is used, which is provided with a tuning range from 400 nm to 600 nm in 25 nm intervals and creates two-photon absorption energy values in order to determine the activation structure of the Material. Using an Nd-YAG laser and tuning between 550 nm and 900 nm, 15 other frequencies are obtained ( FIG. 21), namely (ruby) 506 nm, 525 nm, 544 nm, 562 nm, 580 nm, 595 nm, 611 nm, 626 nm, 642 nm and (Nd-YAG) 724 nm, 744 nm, 764 nm, 784 nm, 804 nm, 822 nm, 841 nm, 860 nm, 878 nm, 894 nm, 910 nm, 926 nm, 942 nm, 958 nm and 972 nm. Continuous color matching of the laser using diffraction gratings, dispersion prisms, tunable etalons, birefringent filters and the like allows selective concentration in bands that are only 1 nm narrow, and staggered tuning elements result in bands of 0.01 or less nm. This enables systems to be designed which, although only two beams are used, are highly selective and can perform multiple operations such as e.g. B. the generation of fiber optic circular components, the programming and reading of memories and the other operations described above ge in a single matrix. The use of sensitizers, if a certain material does not have a suitable two-photon absorption, increases, as previously described, the possibilities for designing systems very much and also the use of bundled radiation states gives further possibilities.

It will be appreciated that the photodetector 31 in Fig. 23 can be replaced with a variety of direction sensitive detectors as previously described to achieve that separate areas of the memory can operate independently and thereby increase capacitance . The time sharing process using fast electronics has also been described which allows it to separate events in time in direct analogy to the similar technique in other areas. It has also been mentioned that vector control of the emitted radiation can be determined by the vector of the exciting radiation during stimulated emission processes, and poly methine colors have been described which can be used in internal laser elements according to the invention. Reference has been made to US Pat. No. 3,829,838 which contains a wealth of information about energy sources, beam controls and mechanisms for specific mounting which, together with the other citations, shows that the prior art is theirs in these fields Makes the description in this application unnecessary.

Plate 1

Refractive power against aperture

P = refractive power [diopter] = 1 / f = -2 N ₁ d

[ N ₁] = m ^-2 [ d ] = m

Example:

d = 5 mm = 5 × 10 ^-3 m P = -2 N ₁ (5 × 10 ^-3 ) = 1 m ^-1 N ₁ = -10² [m ^-2 ] N ₁ = [mm ^-2 ] = -10 ^-4 [mm ^-2] Δη = N ₁ r ² = -10 ^-4 [mm ^-2] r ²

Aperture r (in mm) Index change
Δη

1-10 ^-4 10-0.01 25-0.06 100-1.0

The table above is for a change in refractive power refractive index change required by one diopter at different Aperture values recorded.  

Plate 2

Different combinations of focal lengths f , refractive index coefficients N ₁ and strengths t with a basic refractive index N ₀ = 1.500.

Table 3

Index distribution for a "generalized Wood lens"

Table 4

• A) Level index distribution N ₀ = 1.650 N ₁ = 0.065522
• B) radii r ₁ = 5,928 r ₂ = 419.71
• C) Thickness t = 0.923
• D) Properties of the lens EF = 10.00 BF = 9.40 EP = -0.09 β = 17 °

Table 5

• A) Cylindrical index distribution N ₀ = 1.522 N ₁ = 0.003932 N ₂ = 0.000052
• B) Radii r ₁ = 16.667 r ₂ = -9.484
• C) Thickness t = 8.75
• D) Properties of the lens EF = 50 BF = 50.6 EP = -9.95 β = 17 °

Plate 6

• A) Cylindrical index distribution, 1st range N ₀ = 1.6200 N ₁ = 0.032309 N ₂ = 0.003826
• B) Cylindrical index distribution, 2nd range N ₀ = 1.620 N ₁ = 0.032309 N ₂ = -0.004008
• C) Radii of the interfaces r ₁ = ∞ r ₂ = ∞ r ₃ = ∞
• D) Thickness between the interfaces t ₁ = 0.787 t ₂ = 0.787
• E) Properties of the lens EF = 10.00 BF = 9.51 EP = 0.00 β = 17 °

Plate 7

• A) Cylindrical index distribution N ₀ = 1.5215 N ₁ = 0.0036 N ₂ = 0.0
• B) radii r ₁ = 2.778 r ₂ = 5,416
• C) Thickness t = 0.45
• D) Properties of the lens EF = 10 BF = 9.44 EP = -3.70 β = 26 ° aperture: f / 6.3

Plate 8

• A) Cylindrical index distribution N ₀ = 1.5215 N ₁ = 0.0044 N ₂ = -0.0004
• B) Radii r ₁ = 2.222 r ₂ = 3.615
• C) Thickness t = 0.31
• D) Properties of the lens EF = 10.00 BF = 9.45 EP = -3.40 β = 26 ° aperture: f / 11

Plate 9

List of different combinations of focal length (f) , refractive index coefficient N ₁ and thickness (t) with a basic index N ₀ = 1.450.

Δ N is the total index change, based on values of the lens radius R.

Plate 10 Class I Group 3 systems

Table of energy requirements and wavelength of the 2nd laser, if the first laser is a ruby laser (694 nm).

Plate 11

Plate 12

Claims (17)

1. A method for generating changes in the properties of a storage medium in three dimensions, in which at least two intersecting beams of the same physical type act simultaneously or successively on the medium in an initial state and thereby cause the property changes, characterized in that the medium only contains a single component which can be excited by electromagnetic radiation in the form of a multiphoton absorption, which is converted into a chemically stable final state via at least one temporarily excited intermediate state and that the electromagnetic beams each have different quantum energies or frequencies and to the multiphoton photoactive absorption spectrum thereof single component are adapted. 2. The method according to claim 1, characterized in that that the different states states include differential polymerization. 3. The method according to claim 1, characterized in that the different states are recognizably different Include optical properties. 4. The method according to claim 1, characterized in that the different states states of include various refractive indices. 5. The method according to claim 1 or 4 for generation an optical element, characterized by the Use a volume of the medium enclosing material that comes in a variety distinguishable refractive index states exist and a change in the refractive index state as Response to energy level changes within the Can undergo volume, and through that Use of an energy transfer medium for local generation of the energy level change. 6. The method according to claim 1 or 4 for generation an optical element, characterized by the Use a volume of the medium enclosing material that comes in a variety distinguishable refractive index states exist and a change in the refractive index state in Response to energy level changes within the Can undergo volume, and by control at least one of the two intersecting Rays around the change in the refractive index within to distribute the volume to selected locations.   7. The method according to claim 6, characterized in that that a controlled distribution of the change in Refractive index by controlling both the Beam direction as well as the beam intensity is produced. 8. The method according to claim 1, characterized in that

• a) the first beam has a frequency such that simultaneous absorption of two photons from this beam would be sufficient in energy to excite electrons from the lower to the higher state, but has an intensity which is insufficient to bring about the desired change in properties, and that
• b) the second beam has a frequency such that the simultaneous absorption of two photons from the second beam is not sufficient to excite electrons from the lower to the higher energy state and has a sufficiently high frequency and intensity to effect the desired property changes by the mechanism to generate the simultaneous two-photon absorption from the two beams in that section of the medium in which the first and second beams overlap each other simultaneously.

9. The method according to claim 1, characterized in that

• a) the first beam has a frequency such that the simultaneous absorption of two photons from this beam would be sufficient in energy to excite electrons from the lower to the higher state, but has an intensity which is not sufficient to bring about the desired property changes, that
• b) the second beam has a frequency such that simultaneous absorption of two photons from the second signal by the material is sufficient to excite electrons from the lower to the higher state, but has an intensity which is not sufficient to effect the desired property changes to effect and that
• c) the first and second beams work together to create a cooperative signal at selected locations on the medium, the intensity of which is sufficient to allow the transitions to occur to produce the desired property changes.

10. The method according to any one of the preceding claims, characterized by the use in the medium that in a variety of physico-chemical Behavioral states can exist, one Molecule type that the photochemical excitation in a is capable of increased energy level, the called excitable by multiphoton absorption Component at least part of the energy from the Molecule functioning as a sensitizer can get, but facing the beam alone, that stimulates the sensitizer, is insensitive. 11. The method according to claim 1, characterized in that parts of the Medium with energy from outside the Volume source are supplied, which one reaction is generated to another  Change in the physico-chemical state of behavior of the medium. 12. A three-dimensional volume calculator memory, produced by the method of claim 1, characterized in that the property changes the form of various physico-chemical Adopt behavioral states and at least one binary distribution more distinguishable States that include bit information represent. 13. A three-dimensional volume calculator memory according to claim 12, characterized in that it is reprogrammable and that the binary Interchangeable states through photochemical processes are selective by interacting Rays are induced. 14. A three-dimensional volume calculator memory, produced by the method of claim 1, characterized in that the property changes the form of various physico-chemical States which storage information of the analog type. 15. A device for producing a three-dimensional volume calculator memory using the method according to claim 1, characterized in that

• a) a volume of the storage medium is provided,
• b) guide devices are provided to direct the rays to points of the medium forming certain storage locations from different directions, so that the rays overlap in the respectively selected points in order to bring about a desired change in properties there,
• c) computer devices are provided which record input data, denote the position of the points and use them to calculate control signals for the control devices, and
• d) Detection devices which determine the changed properties at the respective points in order to read out the state prevailing there.

16. The apparatus according to claim 15, characterized in that the detection devices Read out about the light emission. 17. An inhomogeneous optical element produced by the Method according to one of claims 1 to 11.