Method for optically computing a Boolean function having M inputs and associated electro-optical computing system - Patents.com

Abstract

The invention relates to a method (200) for optically computing a Boolean function having M inputs and an associated electro-optical computing system (100). The system comprises a coherent or partially coherent optical radiation source (1) making available M input beams (L, L1), an optical modulation device (3) for generating a modulated optical beam (L2) from the M input optical beams, one or more optical diffusion devices (5) functionally associated with the optical modulation device and for receiving the modulated optical beams, at least one electronic processing device (9, 10) configured to control the optical modulation device (3), and one or more electro-optical sensors functionally associated with the at least one electronic processing device (9, 10). The method comprises a step of: the optical modulation device diffusing two of the M input optical beams (L, L1) to produce a modulated optical beam (L2). M The method includes the step of generating a modulated light beam (L2) consisting of a combination of two light beams (201a). M In each of the combinations, each input light beam (L, L1) can be in an on state (ON) or an off state (OFF). The method comprises making the modulated light beams available through one or more optical diffusion devices to diffuse the two light beams associated with each combination of modulated light beams. M The method comprises a step of generating (201b) random or pseudo-random fields (20). Each random field represents a set of random light intensity variations of points in an observation space (S), and each pseudo-random field represents a set of deterministic light intensity variations of points in the observation space. The method comprises: M based on comparing light intensities of points of one or more regions of an observation space associated with each of the random or pseudorandom fields against at least one threshold light intensity value (TH), M Each of the two random or pseudorandom fields is associated with one of the generated random or pseudorandom fields. MThe method further comprises the step of deriving (201c) M Boolean fields (30), each of which comprises a first point in one or more regions of the observation space where the light intensity of the associated random or pseudo-random field is greater than at least one threshold light intensity value, the first point representing a logical 1, and a second point in one or more regions of the observation space where the light intensity of the associated random or pseudo-random field is less than at least one threshold light intensity value, the second point representing a logical 0. The method further comprises the step of selecting (201d) a target Boolean function (F) having M inputs, and at least one electronic processing device (9, 10) selecting two Boolean fields (30) that satisfy the selected target Boolean function. M The method includes the step of identifying (201e) active points (31) between the first and second points of each of the derived Boolean fields (30), and calculating (202) a Boolean function having M inputs based on the identified active points.

Description

[Technical field]

[0001] The present invention relates to a method for computing or optically generating one or more Boolean functions having one or more inputs, for example M inputs. The present invention also relates to an optical-electronic computing system for optically computing Boolean functions, implementing this method. [Background technology]

[0002] As is known, electronic devices used to perform calculations and / or processing on digital data are characterized by a limited execution speed, because the basic electronic components forming the computing devices, namely transistors, have a signal processing speed that is limited by the propagation delay of the signal itself, which is determined both by the finite size of such electronic components and by the presence of intrinsic capacitances in the components.

[0003] Signal propagation delays increase when the number of electronic devices cascaded together increases, and therefore in complex devices and apparatus consisting of large numbers of transistors, such as logic gates and processors.

[0004] To avoid such drawbacks, it has recently been proposed to use optical radiation to transfer and process information.

[0005] Some recent technical solutions developed for this purpose aim to create devices equivalent to optical transistors that can be combined to create complex computing devices, such as optical type logic gates or optical processors.

[0006] For example, some of these solutions utilize the constructive and destructive interference properties of optical cavities to modulate the optical radiation intensity to which binary information can be associated, where in the case of constructive interference a higher optical radiation intensity is associated with a logic state "1" and in the case of destructive interference a lower optical radiation intensity is associated with a logic state "0".

[0007] Another solution uses the nonlinear optical effects of materials, for example crystals or liquid crystals, to control the light radiation intensity or direction of the main light beam via a control beam. Summary of the Invention [Problem to be solved by the invention]

[0008] However, such known optical solutions have the drawback of not being able to create optical devices similar to transistors that can be configured to implement complex devices comparable to those available with electronic devices and circuits on an integration scale.

[0009] Moreover, a common drawback of these purely optical approaches is that it is currently not possible to combine multiple optical devices to create complex computational devices while maintaining small device sizes and logic gate fan-out values ​​comparable to those obtainable with electronic devices. In particular, achieving reasonable fan-out values, a parameter that indicates correct information transfer between components cascaded together, is a limitation of such approaches.

[0010] To partially avoid such drawbacks, in particular for creating electro-optical computers, hybrid solutions have been proposed, in which optical type information is first converted into electrical type information, the latter is processed by a conventional electronic processing device, and the processing results are converted back into optical type information.

[0011] Although such hybrid solutions have allowed the miniaturization of complex computing devices and the mitigation of the drawbacks associated with the transfer of information between components cascaded together, known electro-optical solutions still have limitations regarding the maximum achievable computing speed.

[0012] There is therefore a strong felt need for a solution for optically processing digital data and information, in particular for optically computing Boolean functions, which makes it possible to overcome the limitations and drawbacks of conventional electro-optical solutions. [Means for solving the problem]

[0013] It is therefore an object of the present invention to provide a method for generating or optically calculating one or more Boolean functions having one or more inputs, for example M inputs, which makes it possible to at least partially overcome the limitations of computing devices made with optical or electro-optical techniques of known types.

[0014] Such an object is achieved by a method for optically computing a Boolean function, for example having M inputs, according to claim 1, where M≧1.

[0015] The invention also relates to an optical-electronic computing system for optically computing Boolean functions according to claim 11.

[0016] In a general and exemplary embodiment, a computing system includes: - a coherent or partially coherent optical radiation source (1) configured to make available M input beams (L, L1), - an optical modulation device (3) adapted to generate a modulated optical beam (L2) from said M input optical beams (L, L1); - one or more optical diffusion devices (5) functionally associated with said optical modulation device (3) and adapted to receive said modulated optical beam (L2); - at least one electronic processing unit (9, 10) configured to control said light modulation device (3); - one or more electro-optical sensors functionally associated with said at least one electronic processing device (9, 10).

[0017] Further, the method (200) of the present invention further comprises: The optical modulator (3) modulates two of the M input optical beams (L, L1) M generating (201a) the modulated light beam (L2) consisting of a combination of Above 2 M In each of the combinations, each input light beam (L, L1) can be in an on state (ON) or an off state (OFF), The method (200) of the present invention comprises: - making the modulated light beam (L2) available by the one or more light diffusion devices (5), thereby diffusing two light beams, each associated with a combination of the modulated light beams (L2), M generating (201b) random or pseudo-random fields (20); Each random field represents a set of random light intensity fluctuations of points in an observation space (S), Each pseudorandom field represents a set of deterministic light intensity fluctuations of points in said observation space (S), The method (200) of the present invention comprises: - said at least one electronic processing device (9, 10) M said one or more electro-optical sensors based on comparing the light intensity of points of one or more areas of said observation space (S) associated with each of said random or pseudo-random fields against at least one threshold light intensity value (TH), M Each of the two random or pseudorandom fields is associated with one of the generated random or pseudorandom fields. M deriving (201c) Boolean fields (30); Above 2 M Each of the Boolean fields (30) is a first point in one or more regions of said observation space (S) for which the light intensity of said random or pseudo-random field associated therewith is greater than said at least one threshold light intensity value (TH), said first point representing a logical 1; a second point in said one or more regions of said observation space (S) for which the light intensity of said associated random or pseudo-random field is less than said at least one threshold light intensity value (TH), said second point representing a logical 0; The method (200) of the present invention comprises: - a step (201d) of selecting a target Boolean function (F) having M inputs to be calculated; - said at least one electronic processing device (9, 10) performing said two operations to satisfy a selected target Boolean function (F) having said M inputs; M identifying (201e) an active point (31) between the first and second points of each of the M derived Boolean fields (30), the active point (31) optically encoding a Boolean function having the M inputs; - the electro-optical computing system (100) computing (202) a Boolean function having the M inputs based on the selected first active point (31).

[0018] The method of the invention and the associated computing system advantageously ensure a higher computing speed than is achievable with known solutions.

[0019] Furthermore, the above-described methods and associated computing systems may be used to generate basic Boolean functions, such as, for example, Boolean NOT, OR, AND, XOR, and EXOR functions, or complex Boolean functions. Such basic functions may be combined to formulate further Boolean functions.

[0020] Preferred and advantageous embodiments of the method for optically calculating Boolean functions and the associated optical-electronic computing system are subject of the dependent claims. [Brief description of the drawings]

[0021] [Figure 1]FIG. 2 illustrates a schematic diagram of an exemplary embodiment of an optical-electronic computing system configured to implement the method for optically computing one or more Boolean functions of the present invention. [Diagram 2] FIG. 2 shows a schematic example of a sequence of operations performed in the encoding step of the inventive method for optically computing a two-input Boolean EXOR function; [Figure 3A] FIG. 3 illustrates the optical radiation intensity of the active zone of a random or pseudo-random field associated with the optical implementation of the Boolean EXOR function of FIG. 2. [Figure 3B] 3A-3C show the optical radiation intensities of corresponding Boolean fields associated with the optical implementation of the Boolean EXOR function of FIG. 2; [Figure 4] 3A-3C show schematic diagrams of examples of operations performed in the error reduction step of the inventive method for optically computing the two-input Boolean EXOR function of FIG. 2; [Diagram 5] 3A-3C show schematic diagrams of examples of operations performed in the convolution step of the inventive method for optically computing a Boolean function; [Figure 6] FIG. 3 shows a schematic representation of the computational steps of the method of the invention for optically computing the two-input EXOR Boolean function of FIG. 2; [Figure 7] 2 illustrates by means of a flow chart the operational stages of a method for optically computing a Boolean function according to the invention; [Figure 8] FIG. 8 illustrates by means of a flow chart the operational stages of the convolution step of the method of the invention for optically computing the Boolean function of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Further characteristics and advantages of the present invention will become apparent from the following description of preferred embodiments, given by way of non-limiting indication and with reference to the accompanying drawings, in which:

[0023] In the above figures, similar or equivalent components are designated by the same reference numerals.

[0024] 1, there is generally indicated by reference numeral 100 an example of an electro-optical computing system configured to implement a method 200 for optically computing a Boolean function having M inputs, or for computing multiple Boolean functions simultaneously, in accordance with the present invention, where M≧1.

[0025] Such a method 200 for optically computing one or more Boolean functions according to the present invention will now be described with reference to FIGS. 2, 3A-3B, 4, 5, 6, 7 and 8. FIG.

[0026] In the following description, the term random field is used to denote a collection of random light intensity fluctuations of points in an observation space S.

[0027] The term pseudorandom field is used to denote the deterministic light intensity variations of points in the observation space S.

[0028] In other words, random fields are unknown and must be characterized, whereas pseudorandom fields have known characteristics.

[0029] The observation space S refers to both a three-dimensional space or 3D space and any subset of a three-dimensional space, such as a plane or any 2D surface, a sphere, a line, or any disjoint region of a three-dimensional space. In a specific, but non-limiting, exemplary embodiment, the observation space S is the surface of a charge-coupled sensor or a CCD (charge-coupled device) sensor.

[0030] Note that the random or pseudo-random field may be larger than the observation space S. Thus, the observation space S allows access to a portion of the random or pseudo-random field.

[0031] Generally, the proposed method 200 consists in using electromagnetic radiation of coherent or partially coherent type, i.e. a coherent or partially coherent light beam generated by a single source 1, typically a laser source. Alternatively, the method 200 uses M independent coherent or partially coherent sources obtained by splitting the coherent light beam generated by the source itself into multiple light beams. Such M light beams are the M inputs of the electro-optical computing system 100 mentioned above.

[0032] In the present invention, a light beam means a combination of light rays.

[0033] The aforementioned electromagnetic radiation of the coherent or partially coherent type is, for example, radiation in the visible spectrum, or alternatively infrared or ultraviolet radiation.

[0034] Generally, with reference to FIG. 1, an electro-optical computing system or system 100 comprises a coherent or partially coherent optical radiation source 1 arranged to make available M input light beams L, L1.

[0035] In particular, each light beam may be turned on or off independently of the others, and thus an ON light beam may be associated with a logic state "1" and an OFF light beam may be associated with a logic state "0."

[0036] Furthermore, the system 100 comprises a light modulation device 3 adapted to generate a modulated light beam L2 from the M input light beams L, L1. The system 100 further comprises one or more light diffusing devices 5 operatively associated with the light modulation device 3 and adapted to receive the modulated light beam L2, and at least one electronic processing device 9, 10 configured to control such light modulation device 3. Furthermore, the system 100 comprises one or more electro-optical sensors operatively associated with the at least one electronic processing device 9, 10.

[0037] In particular, the modulated M light beams L2, which may be configured to propagate in free space or optically guided using fiber optic cables, proceed towards one or more diffusers 5 as mentioned above and generate a random or pseudo-random field, which is used for calculations according to the method 200 of the present invention.

[0038] In other words, a random or pseudo-random field is generated in an observation space S, for example a three-dimensional observation space, by one or more diffusion devices 5 as described above.

[0039] Further structural features of the system 100 are described in detail below.

[0040] A schematic and exemplary embodiment of a method 200 for optically computing a Boolean function with M inputs according to the invention is illustrated by a flow chart with reference to Fig. 7, where M > 1. The method starts with a start step designated STR and ends with an end step designated ED.

[0041] Such a method 200 includes operational steps culminating in the computation or generation of one or more Boolean functions having M inputs. Such operational steps include encoding steps, error reduction steps, convolution steps, and computation steps.

[0042] 2, 3A, 3B, and 7, the method 200 includes modulating two of the M input light beams L, L1 by a light modulation device 3. M The step 201a includes generating a modulated light beam L2 consisting of a combination of two M In each of these combinations, each input light beam L, L1 can be either in an on state (ON) or an off state (OFF).

[0043] Furthermore, the method 200 may be adapted to make the modulated light beam L2 available to one or more light diffusing devices 5 as described above, thereby diffusing two light beams each associated with a combination of the modulated light beams L2. MThe method includes the step of generating 201b random or pseudo-random fields 20.

[0044] Further, the method 200 includes, by at least one) electronic processing device 9, 10, M The generated two random or pseudorandom fields are detected by using one or more electro-optical sensors as described above based on comparing the light intensity of points in one or more regions of the observation space S associated with each of the random or pseudorandom fields against at least one threshold light intensity value TH. M each associated with one of the random or pseudorandom fields M The method includes a step 201c of detecting Boolean fields 30.

[0045] 2 M It should be noted that each of the Boolean 30 fields includes a first point in one or more regions of the observation space S where the light intensity of the associated random or pseudo-random field is greater than at least one threshold light intensity value TH, and thus represents a logical 1, and a second point in said one or more regions of the observation space S where the light intensity of the associated random or pseudo-random field is less than at least one threshold light intensity value TH, and therefore represents a logical 0.

[0046] The method 200 further includes a step 201d of selecting a target Boolean function F having M inputs to be computed.

[0047] Further, the method 200 includes, by at least one electronic processing device 9.10, computing a set of derived 2D functions that satisfy a selected target Boolean function F having M inputs. M This enables identifying 201 e an active point 31 between the first and second points of each of the Boolean functions 30 .

[0048] In other words, such an active point 31 is an optical encoding of a Boolean function having M inputs, and the steps of the method 200 described above together form the encoding step 201 of the method of the present invention.

[0049] It is noted that the comparison process against at least one threshold value TH of the encoding step 201 consists in applying at least one threshold value to each combination of M inputs, so that all points in one or more regions of the observation space S are considered as 1 (or 0 in the case of a negative Boolean field) if the radiation intensity of the random or pseudo-random field is higher than such at least one threshold value TH, or as 0 (or 1 in the case of a negative Boolean field) if the radiation intensity of the random or pseudo-random field is lower than such at least one threshold value TH.

[0050] In an exemplary embodiment, the method 200 M 2 random or pseudorandom fields 20 each associated with one of M 201c includes a step of deriving two Boolean fields 30, M The method includes comparing light intensities of points of one or more regions of an observation space S associated with each of the twenty random or pseudo-random fields against a first, TH1, and at least a second, TH2, threshold light intensity values.

[0051] In this case, 2 M Each of the Boolean fields 30 comprises a further first point in one or more regions of the observation space S where the light intensity of the associated random or pseudo-random field is between the first, TH1 and at least a second, TH2 threshold light intensity value, and thus represents a logical 1, and a further second point in one or more regions of the observation space S where the light intensity of the associated random or pseudo-random field is outside the light intensity range bounded by the first, TH1 and at least a second, TH2 threshold light intensity value, and thus represents a logical 0. Includes.

[0052] The Boolean field 30 derived in the encoding step 201 may be formally represented by the following equation:

[0053] Ci(x): S ⊆ R 3 →[0,1] (1)

[0054] where Ci is the Boolean field, x denotes the spatial coordinates of the Boolean field, S is the observation space, and i is the input combination i=(a1,…,a M ), where a1,…,a M indicates a Boolean input.

[0055] The encoding step 201 of the method 200 includes a step 201 e of identifying points or portions of the observation space S such that a target Boolean function F from the derived Boolean field 30 is satisfied.

[0056] Note that the target Boolean function F is a relation that relates each combination of inputs i to exactly one value of the output. Since the function is Boolean-valued, the value of the output can take on the logical values ​​1 or 0.

[0057] In general, the target Boolean function F may be defined by the following relationship:

[0058] F(i):B M →{0,1} (2)

[0059] where B={0,1} is the set of Boolean values.

[0060] Thus, the points or portions of the region or regions of the observation space S that satisfy the target Boolean function F are the points of space S that satisfy the relationship:

[0061] x:F(i)=C i (x) ∀i (3)

[0062] From the above, and based on equation (3), note in particular that for each combination of inputs i, the active point 31 is a point x in the observation space S such that the value of the target Boolean function F (a function of i) is equal to the value of the Boolean field Ci (produced by combination i) at point x.

[0063] Thus, the above-mentioned step 201e of identifying active points is performed simultaneously with the step of tracking points x in the observation space S, such that for each combination of inputs i, the value of the target Boolean function F (a function of i) is equal to the value of the Boolean field Ci (produced by combination i) at point x.

[0064] Such an operation of identifying active points is performed by the processing units 9 and 10, in particular by verifying, for any point in the observation field x, equation (3) shown above, i.e., verifying that the equality F(i)=Ci(x) holds for any combination of inputs.

[0065] If such an equation at point x is valid for any combination of inputs, then the considered point x is identified as an active point 31. Conversely, if the equation F(i)=Ci(x) at point x is not valid for just one combination of inputs, then such point may be designated as an inactive point rather than an active point.

[0066] Moreover, as mentioned above, the divergent light beam is such as to form a randomly or pseudo-randomly varying intensity distribution in the observation space S. While such intensities are random or pseudo-random, by step 201c, two intensities are generated, one for each combination of inputs. M It is possible to derive a Boolean field, which is the distribution of "1" or "0" values ​​in the observation space.

[0067] Thus, knowing the Boolean field and the objective function F, the active points 31 can be distinguished from the inactive points by verifying the above equation (3) by the processing units 9 and 10. In other words, identifying the active points means identifying the location x of such points in the observation space S with the aid of equation (3).

[0068] The active points do not need to be separated from each other, and in fact they may cover a continuous area of ​​the observation space S. However, all such active points must satisfy equation (3), which can be verified by the processing units 9 and 10.

[0069] From an application point of view, the invention involves creating an electro-optical computing system comprising one or more electro-optical sensors distributed in a three-dimensional 3D observation space S. In particular, such sensors may be distributed without necessarily following a well-defined surface. Note that in the example of Fig. 1, the observation space S is two-dimensional (2D) since it coincides with the face of the CCD sensor.

[0070] Each sensor is configured to measure the intensity of a random or pseudorandom field at a given location x of the three-dimensional observation space S. From such intensities, a Boolean field can be derived by the processing device 9, 10 at the various positions x of the sensor.

[0071] Moreover, using equation (3), active points 31 can be identified by the processing devices 9, 10. Such electro-optical system sensors located in the observation space S are functionally associated with the processing devices 9, 10. Thus, again, such processing devices 9 and 10 are adapted to verify equation (3) at all points x and for all combinations of inputs i.

[0072] Moreover, it is worth noting that the active points 31 in the observation space are not known in advance. Therefore, in the present invention, it is not necessary to place the electro-optical sensor before or after a given point. In fact, the step 201e of identifying points or parts of the observation space S such that the target Boolean function F is satisfied from the derived Boolean field 30 (i.e. active points) is adapted to determine whether the electro-optical sensor is at an active point or at an inactive point.

[0073] After the previously described encoding step 201, the method 200 of the present invention includes the general step 202 of computing, by the electro-optical computing system 100, a Boolean function having M inputs based on the identified active points 31.

[0074] Exemplary embodiments of such a computing step 202 are described with reference to FIGS. 5, 6, 8 and the optical-electronic computing system example of FIG.

[0075] In an exemplary embodiment, such calculating step 202 of the method further comprises: - 2 M a step 2021 of transmitting a first light beam L4 associated with an identified active point 31 for each of the Boolean fields 30 into a detection region 12 of the system 100; a step 2022 of comparing the light intensity transmitted to the detection area 12 against at least one activation light intensity threshold THa; - a step 2023 of associating a logical value 1 to an output state U1 of the Boolean function having M inputs if the light intensity transmitted to the detection area 12 is greater than at least one activation threshold THa, or a logical value 0 to an output state U1 of the Boolean function having M inputs if the light intensity transmitted to the detection area 12 is less than at least one activation threshold THa.

[0076] In a particular exemplary embodiment, the aforementioned transmitting step 2021 includes: - diverging said modulated light beam L2 towards a further light modulation device 4 of the system 100; - a further light modulation device 4 deflecting the first light beam L4 associated with the identified active point 31 towards at least one focusing lens 11; - such at least one focusing lens 11 concentrating the deflected first light beam L4 to generate a first light beam L5 which is transmitted towards the detection area 12.

[0077] The above steps form the superposition step of the inventive method 200. During the superposition step, all or a portion (depending on the value of the threshold) of the light from the active zone 31 identified in the encoding step 201 is transmitted towards the detection region 12.

[0078] Advantageously, the intensity of light transmitted to the detection area 12 is the result of the calculation of a Boolean function having M inputs. Such transmitted light intensity makes it possible to identify and recognize a state in which such intensity exceeds an activation threshold THa as a logical 1 (or 0 in the case of a negated Boolean function) of the Boolean function, and a state in which such intensity is below the activation threshold THa as a logical 0 (or 1 in the case of a negated Boolean function) of the Boolean function.

[0079] In an exemplary embodiment of the method 200, the above-mentioned comparison step 2022 includes: - detecting the light intensity transmitted to the detection area 12 via a first electro-optical sensor 13 of the system 100, for example one or more photodiodes, and converting it into an electrical signal E; - amplifying the electrical signal E by means of electronic amplification means 14, for example an amplifier, to produce a first electrical signal E1; - comparing the first electrical signal E1 against at least one electrical activation threshold ETHa associated with electronic comparison means 15, for example one or more threshold comparators, Such at least one electrical activation threshold ETHa represents the at least one activation light intensity threshold THa mentioned above.

[0080] In certain exemplary embodiments, the comparing step includes comparing the first electrical signal E1 to a first, ETHa1 and at least a second, ETHa2 electrical activation thresholds representing the first, THa1 and at least a second, THa2 activation light intensity thresholds, respectively.

[0081] Based on what has been said above, the output state U1 of the calculated Boolean function is converted into an electrical signal, making the calculation compatible with any electronic circuit.

[0082] It is noted that the activation threshold THa associated with the electronic comparison means 15 is selected such that the target Boolean function F is satisfied, i.e. the activation threshold THa is selected to be less than the intensity of light transmitted to the detection area 12 when a Boolean function value of "1" (or "0" in the case of a negated function) is expected, taking into account intensity variations due to drift or noise. Conversely, the activation threshold THa is selected to be higher than the intensity of light transmitted to the detection area when a Boolean function value of "0" (or "1" in the case of a negated function) is expected, taking into account intensity variations due to drift or noise.

[0083] In an alternative exemplary embodiment, the method 200 involves more than one activation threshold associated with the electronic comparison means 15. However, such thresholds are selected such that the target Boolean function F is satisfied.

[0084] In particular, in the case of the two activation thresholds THa1, ​​THa2, such thresholds are selected such that when a value of 1 is expected for the Boolean function (or 0 in the case of the negated function), the intensity of light transmitted to the detection area 12 is between such two thresholds. Conversely, the light intensity transmitted to the detection area 12 is provided so as to be outside the range between the two activation thresholds THa1, ​​THa2, where a Boolean function value of 0 (or 1 in the case of the negated function) is expected.

[0085] Even in the case of multiple activation thresholds, such thresholds are selected such that the target Boolean function F (or the negated target Boolean function) is satisfied.

[0086] It is noted that the solution of the target Boolean function F by the proposed method 200 is guaranteed by the fact that during the encoding step 201, the very point or part of the Boolean field 30 that satisfies the target Boolean function F is searched for, i.e., the active zone 31 that essentially satisfies the function by applying a single, double or multiple thresholds to the corresponding random or pseudo-random field 20.

[0087] Furthermore, the superposition step of the method advantageously makes it possible to implement various objective Boolean functions, and to implement these functions it is sufficient to direct the channel of optical radiation of the active zone 31 that corresponds to the objective function towards the detection area 12.

[0088] Additionally, the convolution step of the method is useful for increasing noise and drift rejection by convolution of multiple regions that satisfy the same Boolean function.

[0089] In an exemplary embodiment of the method, in the case of a single threshold, the activation light intensity threshold THa can be calculated by the following formula:

[0090] THa=N*TH*k (4)

[0091] where N is the number of active zones 31 transmitted towards the detection region 12, TH is at least one threshold light intensity value, and k is an attenuation constant indicating how much the active zone light intensity 31 is attenuated in the light transferred from the active zone to the detection region 12.

[0092] In a further exemplary embodiment, in the case of two or more activation thresholds, the activation light intensity threshold THaj can be calculated using the following formula:

[0093] THaj=N*THj*k (5)

[0094] where THj denotes the light intensity threshold used in the comparison step 201c described above, j=1, 2, 3, 4 . . .

[0095] 7 and 4, in an optional exemplary embodiment of the method 200 of the present invention, the above-mentioned identification step 201e may be - M input light beams L, L1 M a step 2010 of selecting, for each of the combinations, from among the active points 31 optically encoding a Boolean function having M inputs, a first active point 31', each of which is set such that the absolute value of the difference between the light intensity of the random or pseudo-random field at the active point and at least one threshold light intensity value TH is always greater than a preset positive parameter P; - calculating 202, by the electro-optical computing system 100, a Boolean function having M inputs based on said first selected active point 31'.

[0096] Thus, the calculation step 202 of the method 200 of the present invention comprises: - 2 M a step 2021 of transmitting a first light beam L4 associated with a first active point 31' identified for each of the Boolean fields 30 to the detection area 12; a step 2022 of comparing the light intensity transmitted to the detection area 12 against at least one activation light intensity threshold THa; - a step 2023 of associating to an output state U1 of a Boolean function having M inputs a logical value 1 if the light intensity transmitted to the detection area 12 is greater than at least one activation threshold THa, or a logical value 0 if the light intensity transmitted to the detection area 12 is less than at least one activation threshold THa.

[0097] The steps of the method 200 described above form an error reduction step, which advantageously allows to select active points or portions in such a way as to reduce the probability of introducing calculation errors, especially in the case of unstable or noisy systems.

[0098] The error reduction step may be ignored if the computational system is particularly stable and low-noise, or if the active zones are large enough that the fluctuations in the random or pseudo-random field strength in the active zone due to noise or drift are negligible, i.e. for each combination of inputs and for each active zone, the noise or drift is negligible compared to the absolute value of the difference between the random or pseudo-random field strength at the active point or portion considered and the threshold value.

[0099] The computation step of the inventive method 200 involves computing or optically implementing a target Boolean function (F) with M inputs, using the M light beams (ON or OFF) as inputs of the Boolean function according to computational needs, and the intensities transmitted to the detection area 12 as output. The function implemented according to the proposed method corresponds to the objective function (or multiple objective functions, in case multiple encoding and error reduction steps are performed).

[0100] Example of application of the method With reference to Figures 2, 3A-3B, 4, 5 and 6, the sequence of operations associated with a method 200 of the present invention for optically computing a two-input EXOR target Boolean function, i.e., F(0,0)=0, F(0,1)=1, F(1,0)=1, F(1,1)=0, is described below.

[0101] In particular, with reference to FIG. 2, the encoding step 201 comprises the sequential activation 201a of two input light beams L2 separated from one another using any light modulator, for example of the electro-optical or acousto-optical type, or by an optical shutter.

[0102] In this way, through the diffuser 5, four possible combinations of inputs can be achieved to generate a random 201b or pseudo-random field 20 that is acquired in an observation space S. Such an observation space S is created, for example, at the plane 7 of a charge-coupled sensor of a digital camera, or a charge-coupled device (CCD).

[0103] A next step 201c includes deriving, from the aforementioned generated random or pseudo-random field 20, by the processing device 9, 10, four corresponding Boolean fields 30 associated with the aforementioned random or pseudo-random field based on a comparison against at least one threshold light intensity value TH.

[0104] Further included is a step 201 e of identifying, using the processors 9 , 10 of the system 100 , active zones 31 associated with each of the identified Boolean fields 30 once the target Boolean function F, ie, the EXOR function, has been selected.

[0105] Note that in this embodiment, encoding step 201 is performed during the system manufacturing process.

[0106] Furthermore, in the case of a pseudo-random field, it is not necessary to use a charge-coupled sensor (CCD) surface 7 since the intensity field distribution generated by the diffuser 5 is known in advance. However, the encoding step 201 is useful to identify active zones 31 that satisfy an EXOR function, for example by utilizing a processing unit 9, 10 that applies the aforementioned thresholds against a known pseudo-random field.

[0107] Figures 3A, 3B show the active zones 31 of the random and pseudo-random fields 20 according to Figure 2 and the intensities I of the corresponding derived Boolean fields 30. It is noted that the intensities I of each active zone of the four random or pseudo-random fields generate, by a comparison process with at least one threshold value TH, four corresponding Boolean fields 30 that satisfy the target Boolean function F as described by equation (2).

[0108] Figure 4 shows the error reduction step of the method. Active zones 31 that are very close to the threshold TH are excluded. In other words, only active zones 31 that are far enough away from the threshold TH to form first active zones 31' are selected. Thus, in the example, five first active zones 31' out of seven are selected.

[0109] 5 shows the superposition step of the method 200 performed by the electro-optical system 100. Such a step involves the use of an additional spatial light modulator 4, located in the spatial region of observation S (the detection region or plane of the CCD sensor).

[0110] Such further spatial light modulator 4 is configured to transmit only random or pseudo-random field light towards a focusing lens 11 in the active zone 31, 31'. The lens 11 is adapted to transmit radiation (only in the active zone) towards a detection area 12 close to the focus of the lens.

[0111] The comparison against the activation threshold THa is performed by a photodiode 13 which measures the power or intensity in the detection area 12 and converts it into an electrical signal E. The electrical signal E is amplified to produce an initial electrical signal E1 which is applied to a threshold comparator 15.

[0112] The activation thresholds are selected by taking into account the constant k=A*R*G according to the relationship (4), where kde is the light attenuation A from the active zone 31 to the detection area 12, R is the power-to-current conversion constant of the photodiode 13, and G is the gain of the amplifier 14. Thus, the thresholds of the comparators 15 implement one or more of the activation thresholds THa, selected according to the criteria described in the superposition step.

[0113] FIG. 6 illustrates the computational steps of the method 200 of the present invention, where the objective function F, ie the EXOR function, is computed exactly for any combination of two inputs.

[0114] The Applicant particularly notes that once the encoding step 201 has been carried out, the above-mentioned calculation steps of calculating the EXOR function are extremely fast. In fact, the transmission of the light beams associated with the active zones 31, 31' of the random or pseudo-random field to the focusing lens 11 occurs at the speed of light, so that the propagation delay is practically determined only by the photodiode 13, the amplifier 14 and the comparator 15. However, these electronic devices are very fast, since they are made from basic electronic components used in telecommunications applications having clock frequencies higher than 10 GHz.

[0115] Optical-Electronic System Examples With reference to FIG. 1, an embodiment of an optical-electronic computing system 100 configured to perform a method 200 for optically computing one or more Boolean functions, e.g. having M inputs, according to the present invention will be described in detail below.

[0116] The electro-optical computing system, or simply the system 100, comprises a coherent or partially coherent source 1, for example a laser source, of a light beam L. Such a laser comprises M light beams, where M≧1.

[0117] The system 100 optionally comprises a collimator device 2 adapted to generate M collimated laser beams L 1 from a laser beam L emitted by a source 1 .

[0118] Such M beam lasers L, L1 are the M inputs of the electro-optical computing system 100.

[0119] Furthermore, the system 100 comprises a light modulation device, spatial light modulator, or modulator 3 adapted to generate a modulated light beam L2 from the M input light beams L, L1.

[0120] For example, the spatial light modulator 3 is embodied by a DLP 6500 modulator from Texas Instruments.

[0121] Such a spatial light modulator 3 is controlled by at least one electronic processing unit 9, 10 of the system 100 to separate M input laser beams L1 into M×N groups of laser beams L2 from individual pixels or groups of pixels associated with the modulator 3. In other words, the modulator 3 is configured to generate M×N groups of modulated laser beams L2.

[0122] 1 shows a first electronic processing device 10 and a second electronic processing device 9 that are independent of each other and connected by a data communication line 19. In another exemplary embodiment, the system 100 may comprise a single electronic processing device.

[0123] It is noted that the MxN groups of laser beams L2 are inputs to N devices that implement or compute N Boolean functions with M inputs according to the method 200 of the present invention.

[0124] The system 100 further comprises one or more optical diffusers 5 associated with the light modulation device 3 and receiving the modulated light beam L2.

[0125] In particular, the modulator 3 is configured to turn on or off each of the groups of modulated laser beams L2 described above, independently of the others, by deflecting the input laser radiation L1 towards one or more of the diffusers 5 described above (logic state 1 or on) or absorbers not shown in FIG. 1 (logic state 0 or off).

[0126] In an alternative exemplary embodiment, the input laser beam L, L1 may be split into multiple sub-beams by a beam splitter device, such sub-beams output from the beam splitter may be appropriately modulated by any optical modulator, for example of the electro-optical or acousto-optical type, or by an optical shutter.

[0127] Furthermore, the system 100 includes an optical reflecting element 6, e.g. a mirror, and the group of laser beams output from the diffuser 5, i.e. the diffused laser beam group L3 output from the diffuser 5, propagates in free space towards such mirror 6. In particular, such mirror 6 is reversibly movable by the first electronic processing device 10 from a first operating position, in which the laser beam group L3 output from the diffuser 5 is transmitted towards the observation space S, to a second operating position.

[0128] When mirror 6 is in the above-mentioned first operating position, such mirror is configured to reflect the diffused laser light group L3 towards an observation volume S created, for example at a plane 7 of a charge-coupled device (CCD) sensor of a digital camera. Such a charge-coupled sensor is an electro-optical sensor functionally associated with an electronic processing unit 9, 10.

[0129] In different exemplary embodiments, such a light reflecting element 6 is embodied by a beam splitter, which is in a fixed position with respect to the mirror and does not need to be moved.

[0130] Each of the laser groups L3, which are diffused towards the face 7 of the CCD sensor, is configured to generate in the observation volume S a respective random or pseudo-random 20 field.

[0131] Furthermore, to ensure that the various diffused laser beam groups L3 remain separate and therefore independent from one another, the system 100 involves the use of a first separator 8, e.g., made of an absorbing material, disposed between the diffuser 5 and the observation space S. Such absorbing materials generally comprise blackened materials, paper, plastics, metals (e.g., black anodized aluminum) configured to absorb laser radiation well.

[0132] A digital camera in an observation space S has two pixels in the observation space S as specified in the encoding and error reduction steps of the method 200 of the present invention. M The random or pseudo-random field is operatively associated with a second electronic processing unit 9 of a conventional type adapted to select regions of the random or pseudo-random field.

[0133] The modulator 3 is configured to sequentially turn on or off the input laser beam group L1 by deflecting such beams towards a diffuser 5 to generate a modulated laser beam L2 in the encoding step of the method of the present invention.

[0134] By means of the second electronic processing unit 9 and the camera, the system 100 is configured to select the active zones 31 that satisfy the target Boolean function F to be calculated, in particular by setting an appropriate threshold value TH in the encoding step described above.

[0135] In an exemplary embodiment, the aforementioned second electronic processing unit 9 of the system 100 is also configured to select a first active zone 31 ′ in the error reduction step of the method 200 .

[0136] Once the active zones 31, 31' have been selected, the system 100 is configured to perform the overlapping step of the method 200, in which the mirror 6 is moved to assume a second operating position.

[0137] In such a second operating position of the mirror 6, the laser beam group L3 diffused by the diffuser 5 is transmitted directly to a further spatial light modulator or to a further modulator 4, for example of a type similar to the spatial light modulator 3.

[0138] In order to ensure that the various diffused laser beam groups L3 remain separate and thus independent from one another, the system 100 comprises a second separator 8', similar to the first separator 8, arranged between the diffuser 5 and the further spatial light modulator 4. In particular, such second separator 8' is configured to transmit separate laser beam groups to the further modulator 4 to generate the first laser beam L4.

[0139] To ensure that the random or pseudo-random field generated at the observation plane 7 has the same distribution as the random or pseudo-random field at the additional spatial light modulator 4, the system 100 is designed to ensure that the distance between the mirror 6 and the camera is equal to the distance between the mirror 6 itself and such further spatial light modulator 4.

[0140] Furthermore, the system 100 comprises a focusing lens 11 adapted to receive only the first group of laser beams L 4 corresponding to the active zones 31 , 31 ′ transmitted by the additional spatial light modulator 4 .

[0141] In an exemplary embodiment, laser radiation not corresponding to an active zone is deflected towards a respective absorber (not shown in FIG. 1 ) In this manner, only the active zones selected in the encoding and error reduction steps of the method 200 of the present invention are transmitted towards the detection region 12 of the system 100.

[0142] In particular, system 100, in the embodiment of Figure 1, comprises four focusing lenses 11. Such lenses are associated with respective random or pseudo-random fields of four computing devices, which in a particular embodiment independently and simultaneously compute four different Boolean functions.

[0143] Furthermore, the system 100 comprises a first electro-optical sensor 13 configured to convert the laser radiation focused by each lens 11 into a respective electrical signal E. In particular, the system 100 comprises four photodiodes 13. A respective amplifier device 14 is connected to the output of each photodiode 13.

[0144] The amplified electrical signal E1 or first electrical signal E1 output from the amplifier 14 is proportional to the power or intensity of the integrated laser radiation relative to the area of ​​the photodiode 13.

[0145] Furthermore, the system 100 comprises a comparator 15 arranged to receive the first electrical signal E1 as an input and having, for example, a single threshold or multiple thresholds. In particular, the thresholds of such comparator 15, ETHa in the case of a single threshold or ETHa1 and ETHa2 in the case of two thresholds, are selected according to the superposition step of the method of the invention.

[0146] As mentioned above, the modulator 3 is configured to control M inputs of a Boolean function that is calculated to assume a logically high value or logic "1" (ON) or a logically low value or logic "0" (OFF) according to the computational needs. The output U1 of the single-threshold or multi-threshold comparator 15 is the output state of the calculated target Boolean function F. In other words, the thresholds of the comparator 15 represent activation thresholds that are selected according to the criteria described in the superposition step of the method of the invention.

[0147] It is noted that systems other than those described above can be created to implement the proposed method for optically computing a Boolean function with M inputs.

[0148] In addition to the advantages discussed above, the method 200 for optically computing a Boolean function having M inputs and the associated electro-optical computing system 100 have further advantages and achieve predetermined objectives.

[0149] In particular, the proposed method 200 makes it possible to optically calculate any Boolean function with M inputs. Such a function to be calculated can be established without requiring any modifications to the hardware structure of the system itself, simply by modifying the respective software programs stored in the memories functionally associated with the electronic processing units 9, 10 of the system 100.

[0150] Thus, the system 100 implementing the method of the present invention is a universal, programmable Boolean function generator.

[0151] An additional advantage is that when multiple modulators and multiple high resolution CCDs are used, the method of the present invention allows for an increase in the number of Boolean functions that can be calculated or generated.

[0152] The present invention further relates to a computer program comprising application code executable by at least one electronic processing unit 9, 10 of the electro-optical system 100 for computing one or more Boolean functions having M inputs, implementing the method 200 of the present invention.

[0153] To meet foreseeable needs, those skilled in the art may make modifications and adaptations to the methods and electro-optical computing systems for generating Boolean functions described above, or may replace components with functionally equivalent alternatives, without departing from the scope of the claims. Each of the features described above as belonging to one possible embodiment may be implemented without regard to the other embodiments described.

Claims

1. A method (200) for optically computing a Boolean function having M inputs, where M≧1, implemented by an electro-optical computing system (100), comprising: The computing system is a coherent or partially coherent optical radiation source (1) configured to make available M input beams (L, L1), an optical modulation device (3) adapted to generate a modulated optical beam (L2) from said M input optical beams (L, L1); one or more light diffusing devices (5) functionally associated with said light modulation device (3) and adapted to receive said modulated light beam (L2); at least one electronic processing unit (9, 10) configured to control said light modulation device (3); one or more electro-optical sensors functionally associated with said at least one electronic processing device (9, 10), The method (200) comprises: said optical modulation device (3) modulates two of said M input optical beams (L, L1) Ｍ generating (201a) the modulated light beam (L2) consisting of a combination of 2 above Ｍ In each of the combinations, each input light beam (L, L1) can be in an on state (ON) or an off state (OFF), The method (200) comprises: said modulated light beam (L2) being made available by said one or more light diffusion devices (5), thereby facilitating the production of two light beams each associated with a combination of said modulated light beams (L2); Ｍ generating (201b) random or pseudo-random fields (20), Each random field represents a set of random light intensity fluctuations of points in an observation space (S), Each pseudo-random field represents a set of deterministic light intensity variations of points in said observation space (S), The method (200) comprises: said at least one electronic processing device (9, 10) comprising said two Ｍ said one or more electro-optical sensors based on comparing the light intensity of points of one or more areas of said observation space (S) associated with each of said random or pseudo-random fields against at least one threshold light intensity value (TH), Ｍ Each of the two random or pseudorandom fields is associated with one of the random or pseudorandom fields. Ｍ deriving (201c) Boolean fields (30), 2 above Ｍ Each of the Boolean fields (30) is a first point in one or more regions of said observation space (S) for which the light intensity of said random or pseudo-random field associated therewith is greater than said at least one threshold light intensity value (TH), said first point representing a logical 1; a second point in said one or more regions of said observation space (S) for which the light intensity of said associated random or pseudo-random field is less than said at least one threshold light intensity value (TH), said second point representing a logical 0; The method (200) comprises: a step (201d) of selecting a target Boolean function (F) having M inputs to be calculated; said at least one electronic processing device (9, 10) is adapted to generate a set of two blocks of data satisfying a selected target Boolean function (F) having said M inputs; Ｍ identifying (201e) active points (31) between the first and second points of each of the derived Boolean fields (30), the active points (31) optically encoding a Boolean function having the M inputs; a step (202) of said electro-optical computing system (100) computing a Boolean function having said M inputs based on said identified active points (31), method.

2. 2 above Ｍ The two above-mentioned random or pseudo-random fields are each associated with one of the generated random or pseudo-random fields. Ｍ The step (201c) of deriving the Boolean fields (30) is Ｍ comparing the light intensities of points of one or more regions of said observation space (S) associated with each of the random or pseudo-random fields against a first (TH1) and at least a second (TH2) threshold light intensity value, 2 above Ｍ Each of the Boolean fields (30) is further first points in one or more regions of said observation space (S) having an associated light intensity of said random or pseudo-random field between said first (TH1) and at least a second (TH2) threshold light intensity value, said further first points representing a logical 1; and further second points in said one or more regions of said observation space (S) for which the light intensity of said associated random or pseudo-random field is outside a light intensity range bounded by said first (TH1) and at least a second (TH2) threshold light intensity value, said further second points representing a logical 0. The method (200) of claim 1 for optically computing a Boolean function having M inputs.

3. The calculating step (202) is - 2 above Ｍ transmitting (2021) a first light beam (L4) associated with an identified active point (31) for each of the Boolean fields (30) into a detection region (12) of the system (100); a step (2022) of comparing the light intensity transmitted to said detection area (12) against at least one activation light intensity threshold (THa); and associating (2023) to an output state (U1) of said Boolean function having M inputs a logical value 1 if the light intensity transmitted to said detection area (12) is greater than said at least one activation threshold (THa) or a logical value 0 if the light intensity transmitted to said detection area (12) is less than said at least one activation threshold (THa), The method (200) of claim 1 or 2 for optically computing a Boolean function having M inputs.

4. The transmitting step (2021) includes: - diverging said modulated light beam (L2) towards a further light modulation device (4) of said system (100); - said further light modulation device (4) deflecting said first light beam (L4) associated with said identified active point (31) towards at least one focusing lens (11); such at least one focusing lens (11) concentrating said deflected first light beam (L4) to generate a first light beam (L5) which is transmitted towards said detection area (12), The method (200) of claim 3 for optically computing a Boolean function having M inputs.

5. The comparing step (2022) is - detecting, via a first electro-optical sensor (13) of said system (100), the light intensity transmitted to said detection area (12) and converting it into an electrical signal (E); - electronic amplification means (14) amplifying said electrical signal (E) to produce a first electrical signal (E1); - comparing said first electrical signal (E1) against at least one electrical activation threshold (ETHa) associated with electronic comparison means (15), said at least one electrical activation threshold (ETHa) being representative of said at least one activation light intensity threshold (THa), A method (200) according to claim 3 or 4 for optically computing a Boolean function having M inputs.

6. said comparing step comprising comparing said first electrical signal (E1) against first (ETHa1) and at least second (ETHa2) electrical activation thresholds representing first (THa1) and at least second (THa2) activation light intensity thresholds, respectively; The method (200) of claim 3 for optically computing a Boolean function having M inputs.

7. In the case of a single threshold, the activation light intensity threshold (THa) can be calculated using the following formula: THa=N*TH*k where N is the number of active zones (31) transmitted towards the detection area (12), TH is the at least one threshold light intensity value, and k is an attenuation constant indicating how much the active zone light intensity (31) is attenuated in the light transferred from the active zone to the detection area (12). A method (200) according to one of claims 3 to 5 for optically computing a Boolean function with M inputs.

8. In the case of two or more activation thresholds, the activation light intensity threshold (T) can be calculated using the following formula: THaj=N*THj*k where THj denotes the light intensity threshold used in the comparison step (201c) above, j=1, 2, 3, 4... A method (200) according to one of claims 3 to 6 for optically computing a Boolean function with M inputs.

9. The identifying step (201e) of the M input light beams (L, L1) Ｍ selecting (2010) for each of the combinations a first active point (31') from among active points (31) optically encoding a Boolean function having said M inputs, said first active point (31') being set such that the absolute value of the difference between the light intensity of the random or pseudo-random field at said active point and said at least one threshold light intensity value (TH) is always greater than a preset positive parameter (P); the electro-optical computing system (100) further comprises a step (202) of computing a Boolean function having the M inputs based on the selected first active point (31'), A method (200) according to one of claims 1 to 8 for optically computing a Boolean function with M inputs.

10. The calculating step (202) is - 2 above Ｍ transmitting (2021) a first light beam (L4) associated with the first active points (31') identified for each of the Boolean fields (30) towards a detection region (12) of the system (100); a step (2022) of comparing the light intensity transmitted to said detection area (12) against at least one activation light intensity threshold (THa); and associating (2023) to an output state (U1) of said Boolean function having M inputs a logical value 1 if the light intensity transmitted to said detection area (12) is greater than said at least one activation threshold (THa) or a logical value 0 if the light intensity transmitted to said detection area (12) is less than said at least one activation threshold (THa), The method (200) of claim 9 for optically computing a Boolean function having M inputs.

11. 1. An electro-optical system (100) for computing one or more Boolean functions having M inputs, where M≧1, said system comprising: a coherent or partially coherent optical radiation source (1) configured to make available M input beams (L, L1), an optical modulation device (3) adapted to generate a modulated optical beam (L2) from said M input optical beams (L, L1); one or more light diffusing devices (5) functionally associated with said light modulation device (3) and adapted to receive said modulated light beam (L2); at least one electronic processing unit (9, 10) configured to control said light modulation device (3); one or more electro-optical sensors functionally associated with said at least one electronic processing unit (9, 10); a light reflecting element (6) adapted to receive a diffused light beam (L3) from said one or more light diffusing devices (5) and configured to transmit said diffused light beam (L3) towards an observation space (S) and / or towards a further light modulation device (4) controlled by said at least one electronic processing device (9, 10); one or more focusing lenses (11) adapted to receive the first light beam (L4) from said further light modulation device (4) and to concentrate said first light beam (L5) transmitted towards a detection area (12); a first electro-optical sensor (13) configured to convert each of said transmitted first light beams (L5) into a respective electrical signal (E); electronic amplification means (14) connected to the output of said first electro-optical sensor (13) and adapted to generate a first electrical signal (E1) from said electrical signal (E); - electronic comparison means (15) connected to said electronic amplification means (14) and receiving as input said first electrical signal (E1); said at least one electronic processing device (9, 10) being configured to carry out the steps of a method (200) according to one of claims 1 to 10, System (100).

12. the light reflecting element (6) is a mirror reversibly movable by the at least one electronic processing device (9, 10) from a first operating position, in which the diffused light beam (L3) is transmitted towards a viewing space (S), to a second operating position, in which the diffused light beam (L3) is transmitted towards the further light modulation device (4) controlled by the at least one electronic processing device (9, 10), The electro-optical system (100) of claim 11.

13. said observation space (S) being the plane (7) of a charge-coupled sensor or charge-coupled device (CCD) of a digital camera; Electro-optical system (100) according to claim 11 or 12.

14. a first separator (8) made of an absorbent material and arranged between the one or more light diffusing devices (5) and the observation space (S); a second separator (8') similar to the first separator (8) and arranged between the one or more light diffusing devices (5) and the further light modulating device (4), An electro-optical system (100) according to one of claims 11 to 13.

15. A computer program comprising application code executable by at least one electronic processing unit (9, 10) of an electro-optical system (100) for computing one or more Boolean functions with M inputs, where M≧1, to implement the method according to claims 1 to 10.

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