Integrated optoelectrical converter

Abstract

The present invention relates to a differential optoelectricalal converter that transforms an optical anbit into an electrical anbit. The convertor uses two beam splitters (31, 32) that receive optical signals from the anbit, each one splitting the signal into two beams; a beam combiner (4) that combines a beam that exits each beam splitter; and three photodiodes (51, 52, 53) connected to a beam that exits each beam splitter and to the output of the beam combiner, each photodiode generating a photocurrent, the photocurrents being processed by a signal processing module (6) to obtain the electrical anbit (200). The invention provides an efficient solution for analog computation designed to harness the benefits of PIP technology and establish a bridge between integrated photonics and integrated electronic by means of optoelectrical conversion.

Description

[0001] INTEGRATED OPTO-ELECTRICAL CONVERTER DESCRIPTION OBJECT OF THE INVENTION

[0002] The present invention falls within the field of differential opto-electric converters.

[0003] Specifically, the invention focuses on an integrated opto-electrical converter that transforms an optical analog bit (anbit) into an electrical anbit, using interferometry and direct detection strategies. This converter can be implemented using three different hardware architectures, based on beam splitters and combiners, optical hybrids, photodiodes, and a signal processing module.

[0004] BACKGROUND OF THE INVENTION

[0005] For more than five decades, digital electronics has met the growing demand for computing power thanks to the periodic doubling of transistor density in integrated circuits. Currently, this scaling law is reaching its fundamental limit, leading to the emergence of a wide range of applications that are incompatible with digital electronics, specifically those involving analog processing of multiple data points in real time, such as medical diagnostic imaging, drug design, and robotic control, among others.

[0006] In this case, an analog computing approach implemented in a reconfigurable, non-electronic technology, such as programmable integrated photonics (PIP), can be more efficient than digital electronics for these emerging applications. However, current analog computing models (neuromorphic and quantum computing) were not designed to leverage the benefits of programmable integrated photonics (PIP). The integrated opto-electric converter of the present invention harnesses the full potential of PIP technology.

[0007] DESCRIPTION OF THE INVENTION

[0008] The present invention relates to an integrated opto-electrical converter. This invention arises within the context of a new theory of analog computing, called Analog Programmable Photonic Computing (APC), specifically designed to unlock the full potential of PIP technology. The central concept revolves around the idea of ​​performing operations on a new unit of information, the anbit, conceived as a two-dimensional analog function and adapted to the basic building block of PIP circuits.

[0009] Since integrated photonics and integrated electronics must coexist within a PIP platform, it is crucial to bridge the gap between these two technologies by performing an opto-electrical conversion of anbits. This opto-electrical conversion is possible using the hardware structures presented in this invention, which allow anbits to be moved from the optical domain to the electrical domain, employing interferometry and direct detection strategies.

[0010] The APC's unit of information, the anbit, can be mathematically described as \ / J) = \ / JO\

[0011]

[0012] |1). Here, a user's information is encoded by I >o|, |ii| and p. An anbit can be physically implemented by means of two optical pulses propagated by two different waveguides, where the first optical pulse has a time delay with respect to the second optical pulse, as illustrated in Figure 1. The optical pulses are described by two real wave packets |io(t)| and | >i(t)|, and the time delay is ΔT = φ / ω₀, where ω₀ is the central angular frequency of the electromagnetic field and p is the differential phase between the two pulsed waves.

[0013] The APC performs the anbit computational operations in the optical domain with the PIP circuits, and subsequently, the user information must be recovered from these two optical pulses using optoelectronic technology.

[0014] In this context, the invention addresses the problem of how to transform user information encoded by these two optical pulses into electrical photocurrents. To this end, three different optoelectric hardware structures based on interferometry and direct detection are proposed.

[0015] Each structure comprises at least two beam splitters that receive optical signals from at least one optical channel and split the optical signal into at least two beams each. Two of the three structures also comprise at least one beam combiner connected to the output of the beam splitters and configured to combine at least one beam from each beam splitter. The third structure comprises at least one optical hybrid connected to at least one beam from each beam splitter and inducing optical interference between pulses I > 01 and I > i.

[0016] Each structure comprises at least three photodiodes configured to generate a photocurrent, which are connected to at least one beam exiting each of the beam splitters, which are not combined in the beam combiner or connected to the optical hybrid; and which are connected to the output of the beam combiner or the optical hybrid. Furthermore, each structure comprises a signal processing module connected to the photodiodes and configured to retrieve user information in the electrical domain from the photocurrents generated by the photodiodes.

[0017] In summary, the invention relates to an integrated opto-electric converter:

[0018] configured to transform at least one optical anbit into at least one electrical anbit;

[0019] where the at least one optical anbit comprises:

[0020] or A first optical pulse |^o| and a second optical pulse e^il, where the first optical pulse has a delay with respect to the second optical pulse; and

[0021] where the opto-electric converter comprises:

[0022] at least two beam splitters that receive the optical signals from the optical array and split the optical signal into at least two beams each, at least one of the following components:

[0023] or at least one beam combiner that is connected to the output of the at least two beam splitters configured to combine at least one beam coming from each of the at least two beam splitters; or at least one optical hybrid that is connected to at least one beam coming from each of the at least two beam splitters, at least three photodiodes configured to generate a photocurrent and connected to at least one beam coming from the at least two beam splitters that are not combined in the at least one beam combiner or are not connected to the at least one optical hybrid, and connected to the output of the at least one beam combiner or to the output of the at least one optical hybrid; and

[0024] a signal processing module connected to at least three photodiodes and configured to obtain a signal in the electrical domain from the photocurrents generated in the at least three photodiodes.

[0025] Optionally, the at least one optical anbit is mathematically described as \x = \ / JO\

[0026]

[0027] |1); where |io(t)| and | >i(t)| son real wave packets that define the two optical pulses with which the anbit is implemented, |0) and |1) are the fundamental propagation modes of two different decoupled parallel waveguides and <p es la fase diferencial entre ambos pulsos.

[0028] Optionally, the at least three photodiodes are PIN photodiodes that have the same responsiveness (52).

[0029] Optionally, the at least two beam splitters have a 50:50 split ratio.

[0030] Optionally, at least one optical hybrid is a 90° optical hybrid.

[0031] Optionally, a first beam splitter divides the optical pulse power |^o| into two beams and a second beam splitter divides the optical pulse power

[0032]

[0033] in two bundles.

[0034] Optionally, a first photodiode is connected to a beam coming out of a first beam divider and generates the photocurrent =52|^o| 2 / 2.

[0035] Optionally, at least one beam combiner is connected to two beams exiting each of at least two beam splitters. Optionally, at least one optical hybrid is connected to two beams exiting each of at least two beam splitters.

[0036] Optionally, a second photodiode is connected to a beam exiting at least one beam combiner and generates the photocurrent / B =( 2 / 4){|^o| 2 +| ii 1 2- 2| >o| | |cos<}

[0037] Optionally, a third photodiode is connected to a beam coming out of a second beam splitter and generates the photocurrent / C = 2| > I| 2 / 2.

[0038] Optionally, two balanced photodiodes are connected to two beams coming out of at least one beam combiner and generate the photocurrent / B =52|^o| | ii |cos<.

[0039] Optionally, two balanced photodiodes are connected to two beams that emerge from at least one optical hybrid and generate the photocurrent I B = (52 / 2) |T / >0I |^i I coscp.

[0040] Optionally, two balanced photodiodes are connected to two beams that emerge from at least one optical hybrid and generate the photocurrent I B ' = (52 / 2) |T / >0I |^i I sin <p. Opcionalmente, el módulo de procesamiento de señales está conectado a las fotocorrientes I_A, I_B y I_C y obtiene el anbit eléctrico a partir de dichas fotocorhentes.

[0041] Optionally, the signal processing module is connected to the photocurrents I_A, I_B, I_B' and I_C and obtains the electrical signal from these photocurrents.

[0042] The invention also relates to a method for transforming an optical anbit into an electrical anbit using the converter described above, comprising the following steps:

[0043] transmit the optical signals of the anbit to at least two beam splitters; divide the optical pulse power |^o| into two beams using one of at least two beam splitters;

[0044] divide the power of the optical pulse |ti \e ¡< p into two beams using one of at least two beam splitters;

[0045] combine at least two beams coming from each of the at least two beam splitters using at least one beam combiner or connect the at least two beams coming from each of the at least two beam splitters to at least one optical hybrid; connect one of the at least three photodiodes to a beam coming from one of the at least two beam splitters to generate the photocurrent ¿4= 2| >o| 2 / 2; connect at least one of the at least three photodiodes to at least one beam coming out of it, at least one beam combiner to generate the photocurrent / B=( 2 / 4){|^O| 2 +|^II 2- 2| >o|| 'il cos < Z'} or / B =52|^o| |ii |cos<; or connect at least four photodiodes to at least four beams coming out of it, or at least one optical hybrid to generate the photocurrents I B = (52 / 2)1^011^11 cos <p y I B ' = (52 / 2)1^011^11 sin <p.;

[0046] connect one of at least three photodiodes to a beam coming from one of at least two beam splitters to generate the photocurrent / C = 2|^I| 2 / 2; apply a signal processing routine to the IA B IC or IA B, h'ylc photocurrents using the signal processing module to obtain the electrical anbit.

[0047] Optionally, the method comprises connecting a photodiode to a beam emanating from it and at least one beam combiner to generate the photocurrent / B=( 2 / 4){|^O| 2 +|^I| 2- 2| > O| |ii |cos<}.

[0048] Optionally, the method comprises connecting two balanced photodiodes to two beams emanating from them, or at least one beam combiner to generate the photocurrent / B= 2| > O|| 'I|COS<

[0049] Optionally, the method comprises connecting two balanced photodiodes to two beams emanating from at least one optical hybrid to generate the photocurrent I B = (52 / 2) | >0| l >i I cos < PY connect two more balanced photodiodes to two more beams coming out of it at least one optical hybrid to generate the photocurrent I B ' = (52 / 2)| >oll >il sin <p.

[0050] DESCRIPTION OF THE DRAWINGS

[0051] To complement the description being made and in order to help a better understanding of the characteristics of the invention, according to a preferred example of its practical embodiment, a set of drawings is included as an integral part of said description, in which, for illustrative and non-limiting purposes, the following has been represented: Figure 1: Shows the physical implementation of an anbit, using two optical pulses propagated by the fundamental modes of two different parallel decoupled waveguides, where the first optical pulse has a delay with respect to the second optical pulse.

[0052] Figure 2: Shows a graph of the time delay between the two optical pulses.

[0053] Figure 3: Shows the structure of an anbit differential opto-electrical converter, in which optical interference is measured at the output of a beam combiner using unbalanced direct detection.

[0054] Figure 4: Shows the structure of an anbit differential opto-electrical converter, in which optical interference is measured at the output of a beam combiner using balanced forward detection.

[0055] Figure 5: Shows the structure of a one-anbit differential quadrature opto-electric converter, in which optical interference is induced by the use of a 90° optical hybrid.

[0056] PREFERRED EMBODIMENT OF THE INVENTION

[0057] The present invention relates to an integrated opto-electric converter that transforms an optical anbit (100) into an electrical anbit (200).

[0058] Figure 1 shows the physical implementation of an anbit, using two optical pulses propagated by the fundamental modes |0>, |1) of two different decoupled parallel waveguides, where the first optical pulse has a delay with respect to the second optical pulse. The optical pulses are described by two real wave packets (1) and (2) defined by |io(t)| and

[0059]

[0060] respectively. The anbit can be mathematically described as \ / J) = |^o| |0) +

[0061]

[0062] | 11>, where p is the differential phase between both pulses.

[0063] Figure 2 shows a graph of the time delay AT between the two optical pulses, where the x-axis represents time and the y-axis represents the amplitude of the optical pulse. AT is equal to <p / ú)o, donde ω₀ es la frecuencia angular del campo electromagnético. La Figura 3 muestra una primera realización de un convertidor opto-eléctrico que recibe las señales ópticas de un anbit óptico (100) y que es implementado con un circuito que comprende dos divisores de haz (31, 32), un combinador de haces (4), tres fotodiodos (51, 52, 53) y un módulo de procesamiento de señales (6). El divisor de haz (31) recibe el pulso óptico |t0| y divide la potencia de dicho pulso óptico en dos haces (Oí, O2). El divisor de haz (32) recibe el pulso óptico |t i le^y divide la potencia de dicho pulso óptico en dos haces (O3, O4). El combinador de haces (4) está conectado a la salida de los dos divisores de haz (31, 32) y combina los dos haces (O2, O3) que salen de cada uno de los dos divisores de haz (31, 32).The beam combiner (4) induces optical interference between the pulses |^o| and.

[0064]

[0065] by combining the two beams (O2, O3).

[0066] The first photodiode (51) is connected to the beam (Oi) exiting the beam splitter (31) and generates a photocurrent I_A=ℛ|ψ₀|² / 2. The second photodiode (52) is connected to a beam (Os) exiting the beam combiner (4) and generates a photocurrent I_B=(ℛ / 4){|ψ₀|²+|ψ₁|²−2|ψ₀||ψ₁|cosφ}, thus recovering the differential phase p of the optical anbit (100). The third photodiode (53) is connected to the beam (O4) exiting the beam splitter (32) and generates a photocurrent I_C=ℛ|ψ₁|² / 2. The signal processing module (6) obtains the anbit in the electrical domain, recovering the user information encoded by |^o|, |ii| yp, from the photocurrents I A, IB and Ic generated by the three photodiodes (51, 52, 53), using a signal processing routine based on the photocurrent equations.

[0067] Figure 4 shows a second embodiment of the opto-electric converter, implemented with a circuit similar to that illustrated in Figure 3, with the main difference being in the output of the beam combiner (4). The circuit of the second embodiment comprises two balanced photodiodes (52', 52") connected to two beams (O₅, O₆) exiting the beam combiner (4), generating a photocurrent I_B=ℛ|ψ₀||ψ₁|cosφ, thus eliminating the common terms |^o| 2 and |ii | 2 of I B .

[0068] Figure 5 shows a third embodiment of the opto-electric converter that is implemented with a circuit similar to the circuit illustrated in Figure 3, with the main difference being that this circuit comprises, instead of the beam combiner (4), an optical hybrid (7) connected to the two beams (O2, O3) coming out of each of the two beam splitters (31, 32) to induce optical interference between the pulses | >0|

[0069]

[0070] And that ue It allows the recovery of the differential phase over the entire interval [0,2TT) radians. In this embodiment, the two balanced photodiodes (52', 52") are connected to two beams (Os, Os) that emerge from the optical hybrid (7) and generate a photocurrent I B = (52 / 2) |T / >0I |^i I cos<?■ El circuito de la tercera realización comprende adicionalmente dos fotodiodos balanceados (53', 53”) que están conectados a dos haces (O7, Os) que salen del híbrido óptico (7) y que generan una fotocorriente I B ' = (52 / 2) | >01 l >i I sin <p. Finalmente, el módulo de procesamiento de señales (6) obtiene el anbit en el dominio eléctrico recuperando la información de usuario codificada por |t o|, |i i I Y a starting from the photocurrents I A , YO B , YO B 'and I c generated by the six photodiodes (51, 52', 52", 53', 53", 53), using a signal processing routine based on the photocurrent equations.

Claims

CLAIMS 1. Integrated opto-electric converter: configured to transform at least one optical anbit (100) into at least one electrical anbit (200); where the at least one optical anbit comprises: or A first optical pulse |^o| and a second optical pulse where the first optical pulse is delayed with respect to the second optical pulse; and where the opto-electric converter comprises: at least two beam splitters (31, 32) that receive the optical signals from the optical array (100) and split the optical signal into at least two beams each, at least one of the following components: or at least one beam combiner (4) that is connected to the output of the at least two beam splitters (31, 32) configured to combine at least one beam coming out of each of the at least two beam splitters (31, 32); or or at least one optical hybrid (7) that is connected to at least one beam coming out of each of the at least two beam splitters (31, 32), at least three photodiodes (51, 52, 52', 52", 53', 53", 53) configured to generate a photocurrent and connected to at least one beam coming out of the at least two beam splitters (31, 32), which are not combined in the at least one beam combiner (4) or are not connected to the at least one optical hybrid (7), and connected to the output of the at least one beam combiner (4) or to the output of the at least one optical hybrid (7); and a signal processing module connected to at least three photodiodes (51, 52, 52', 52", 53', 53", 53) and configured to obtain a signal in the electrical domain from the photocurrents generated in at least three photodiodes (51, 52, 52', 52", 53', 53", 53).

2. The converter of claim 1 wherein the optical anbit (100) is mathematically described as \x = |^o| |0) + | |1); where |io(t)| (2) are actual wave packets that define the two optical pulses with which the anbit is implemented, |0) and |1) are the fundamental propagation modes of two different decoupled parallel waveguides and <p es la fase diferencial entre ambos pulsos.

3. el convertidor de reivindicación 1 en el que los fotodiodos (51, 52, 52', 52", 53', 53", 53) son pin tienen una misma responsividad (52).

4. divisores haz (31, 32) relación división 50:

50.

5. híbrido óptico (7) un 90°.

6. divisor (31 ) divide potencia del pulso |t0| dos haces (oí, o2).

7. (32) |t i \e'v>in two bundles (O3, O4).

8. The converter of claim 1 wherein the photodiode (51) is connected to the beam (Oi) coming out of the beam splitter (31) and generates the photocurrent =5?| >o| 2 / 2.

9. The converter of claim 1 wherein the beam combiner (4) is connected to the beams (O2, O3) coming out of each of the beam splitters (31, 32).

10. The converter of claim 1 wherein the optical hybrid (7) is connected to the beams (O2, O3) coming out of each of the beam splitters (31, 32).

11. The converter of claim 1 wherein the photodiode (52) is connected to the beam (Os) coming out of the beam combiner (4) and generates the photocurrent / B =(52 / 4){|^O| 2 +|^II 2- 2| >o|| >i|cos<}.

12. The converter of claim 1 wherein the photodiode (53) is connected to the beam (O4) coming out of the beam splitter (32) and generates the photocurrent / C =52|^I| 2 / 2.

13. The converter of claim 1 wherein two balanced photodiodes (52', 52") are connected to two beams (Os, Oe) coming out of the beam combiner (4) and generating the photocurrent / B =52|^o| |ii |cos<.

14. The converter of claim 1 wherein two balanced photodiodes (52', 52") are connected to two beams (Os, Oe) emanating from the optical hybrid (7) and generating the photocurrent I B = (52 / 2) |T / >0I |^i I cos <p 15. The converter of claim 1 wherein two balanced photodiodes (53', 53") are connected to two beams (O7, Os) emanating from the optical hybrid (7) and generating the photocurrent I B ' = (52 / 2) |T / >0I |^i I sin <p 16. The converter of claim 1 wherein the signal processing module (6) is connected to the photocurrents I^hylc and obtains the electrical energy (200) from said photocurrents.

17. The converter of claim 1 wherein the signal processing module (6) is connected to the photocurrents IA, I B , YO B 'yIc and obtains the electric current (200) from said photocurrents.

18. Method for transforming an optical anbit (100) into an electrical anbit (200) using the converter described in any of claims 1 to 17 comprising the following steps: transmit the optical signals of the anbit to at least two beam splitters (31, 32); divide the optical pulse power |^o| into two beams (Oi, O2) using the beam splitter (31); divide the power of the optical pulse into two beams (O3, O4) using the beam splitter (32); combine the beams (O2, O3) coming out of the at least two beam splitters (31, 32) using at least one beam combiner (4) or connect the beams (O2, O3) coming out of the at least two beam splitters (31, 32) to at least one optical hybrid (7); Connect the photodiode (51) to the beam (Oi) coming out of the beam divider (31) to generate the photocurrent =52|^o| 2 / 2; connect at least one photodiode (52, 52', 52") to at least one beam (Os, Oe) coming out of the beam combiner (4) to generate the photocurrent / B=( 2 / 4){|^O| 2 +|^II 2- 2|io| |ii |c°s<} o / B = 2|^O| |ii |cos<; or connect at least four photodiodes (52', 52", 53', 53") to at least four beams (Os, Oe, O7, Os) that come out of the optical hybrid (7) to generate the photocurrents I B = (52 / 2)1^011^11 cos <p y I B ' = (52 / 2)1^011^11 sin <p. connect the photodiode (53) to the beam (O4) coming out of the beam divider (32) to generate the photocurrent / C = 2| > I| 2 / 2; Apply a signal processing routine to the photocurrents IA B IC or IA, IB, IB' and Ic using the signal processing module (6) to obtain the electrical anbit (200).

19. The method of claim 18 wherein the action of connecting at least one photodiode (52, 52', 52") to at least one beam (Os, Os) exiting the beam combiner (4) is carried out by connecting the photodiode (52) to a beam (Os) exiting the beam combiner (4) to generate the photocurrent / B =( 2 / 4){|^O| 2 +|^II 2- 2| >o|| 'i|cos<}.

20. The method of claim 18 wherein the action of connecting at least one photodiode (52, 52', 52") to at least one beam (Os, Os) coming out of the beam combiner (4) is carried out by connecting two balanced photodiodes (52', 52") to two beams (O5, Oe) coming out of the beam combiner (4) to generate the photocurrent I B = 2|^O||^I|COS< Z'- 21. The method of claim 18 wherein the action of connecting at least four photodiodes (52', 52", 53', 53") to at least four beams (O5, Oe, O7, Os) emanating from the optical hybrid (7) is carried out by connecting two balanced photodiodes (52', 52") to two beams (Os, Oe) emanating from the optical hybrid (7) to generate the photocurrent I B = (52 / 2) I > O I l >i I cos <p y conectando dos fotodiodos balanceados (53', 53") a dos haces (O7, Os) que salen del híbrido óptico (7) para generar la fotocorriente I B ' = (52 / 2) | >01 l >i I sin

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