Ultra-low temperature waveform source

Abstract

A method for providing an electrical waveform (V(t), EPAT1) at cryogenic temperatures includes: - providing an optical signal (CLB1) including an optical waveform (OPAT1); - directing the optical signal (CLB1) to a cryogenic chamber (VES1); and - converting the optical waveform (OPAT1) of the optical signal (CLB1) into an electrical waveform (EPAT1) within the cryogenic chamber (VES1).

Description

[Technical Field]

[0001] The present invention relates to generating electrical waveforms. [Background technology]

[0002] The operation of a quantum computer may require providing high bandwidth electrical waveforms.

[0003] The electrical waveform may require cryogenic temperatures, e.g., temperatures below 5 K or even below 1 K. Critical components of quantum computers may operate at cryogenic temperatures, e.g., temperatures below 5 K or even below 1 K.

[0004] Electrical waveforms can be generated at room temperature and conducted to the cryogenic chamber via electrical feedthroughs and coaxial cables. However, electrical feedthroughs and cables can conduct heat into the cryogenic chamber to the extent that the heating power of the feedthrough exceeds the cooling capacity of modern refrigerators. Conducting high-frequency electrical signals into the cryogenic chamber can generate heat, preventing the chamber from maintaining the desired cryogenic temperature. The Wiedemann-Franz law states that in metals, heat and electrical conductivity are proportional to each other because heat is mediated mostly by electrons. The limited cooling capacity and the large amount of heat conducted through the feedthroughs set fundamental limitations for transmitting electrical high-frequency signals and electrical data signals from room temperature to cryogenic temperatures. Summary of the Invention [Problem to be solved by the invention]

[0005] It is an object to provide a method for generating an electrical waveform.It is an object to provide a signal generator for providing an electrical waveform. [Means for solving the problem]

[0006] According to one aspect, there is provided a method of providing an electrical waveform (V(t), EPAT1), comprising the steps of: - providing a first optical signal (CLB1) comprising one or more optical pulse sequences (OPAT1, OPAT2); - directing a first optical signal (CLB1) into a cryogenic chamber (VES1); - distributing optical pulses (CLB1) of a first optical signal to two or more photoelectric conversion devices (OEC1, OEC2) via optical waveguides (CWG1, CWG2); - converting the optical pulses (CLB1) of the first optical signal into electrical pulses in a cryogenic chamber (VES1), The temperature (T1) in the cryogenic chamber (VES1) is below 20K. A method is provided.

[0007] Further aspects are defined in the claims.

[0008] The scope of protection sought for various embodiments of the present invention is defined by the independent claims. To the extent that any embodiments described herein do not fall within the scope of the independent claims, they are to be construed as examples useful for understanding various embodiments of the present invention.

[0009] The signal generating device may include an optical pulse generator that provides optical pulses, an optical feedthrough that directs the optical pulses to the cryogenic chamber, and at least one optical-to-electrical converter that converts the optical pulses to electrical pulses within the cryogenic chamber.

[0010] The signal generator may provide selectable and / or arbitrary voltage waveforms. The signal generator may operate as an optically driven ultrafast cryogenic arbitrary waveform source. The signal generator may generate signal frequencies, for example, from 0 Hz to over 100 GHz.

[0011] The device may be arranged to provide a selectable electrical waveform. The device may be arranged to provide a user selectable electrical waveform. The device may be arranged to provide any electrical waveform.

[0012] Converting optical pulses to electrical pulses at cryogenic temperatures can enable high bandwidth with good energy efficiency. Good energy efficiency of the signal generator can facilitate maintaining the cryogenic temperature of the cryogenic chamber. The thermal power conducted to the cryogenic chamber via the optical feedthrough can be very low so as not to exceed the limited cooling capacity of the cryogenic chamber's cooling system.

[0013] Conducting the radio frequency signal through an optical feedthrough into the cryogenic chamber and converting the optical pulses into electrical pulses within the cryogenic chamber may allow for reduced heat leakage into the cryogenic chamber. Because there is no need to conduct a radio frequency electrical waveform into the cryogenic chamber, heat conduction into the cryogenic chamber through the electrical feedthrough may be reduced or minimized.

[0014] Optical feedthroughs may allow for higher bandwidths compared to those allowed by electrical feedthroughs.

[0015] The optical arbitrary pulse pattern generator can be arranged to generate pulse patterns at very high frequencies, such as above 100 GHz.

[0016] The optical pulse generator can generate an optical binary pulse pattern in which logic pulses are generated at a fixed frequency, with each logic pulse having a signal level of 0 or 1. An existing pulse can correspond to a signal level of 1. A missing or attenuated pulse can correspond to a signal level of 0. Some of the optical pulses can represent a logic level (1), i.e., the presence of a pulse, while other optical pulses can represent a logic level (0), i.e., the absence of a pulse. When these pulses are coupled to a high-speed optical-to-electrical converter, each existing optical pulse can be converted into an electrical pulse. As a result, the device can provide any electrical pulse pattern.

[0017] The electrical pulse pattern may be low-pass filtered to provide a filtered output. The instantaneous voltage level of the filtered output may be proportional to the frequency of the optical pulses (logic level 1) present. Thus, the instantaneous voltage level of the filtered output may be controlled by selecting the frequency of the optical pulses present. The signal generator may include one or more ultrafast optical-to-electrical converters and one or more low-pass filters to generate the electrical waveform by delta-sigma conversion at cryogenic temperatures.

[0018] The photoelectric converter may be, for example, a photodiode, a plasmonic photodetector, or a nanowire detector, and may convert the optical pulses into electrical pulses. The low-pass filter may form an output waveform from the electrical pulses. The device may include an electrical low-pass filter that converts the frequency of the electrical pulses into a voltage level of the electrical output waveform. The cutoff frequency of the low-pass filter may be less than the frequency of the electrical pulses. The low-pass filter may remove ultrafast signal components and ensure that the voltage level of the output signal is proportional to the frequency of the optical pulses, which represents signal level 1.

[0019] The device may convert a digital optical signal into an analog electrical waveform. The device may operate as a digital-to-analog converter. The device may perform delta-sigma conversion by filtering the output signal of one or more optical-to-electrical conversion units with a low-pass filter.

[0020] In one embodiment, the outputs of multiple photoelectric converters may be combined, for example, to increase the signal output amplitude, improve the signal dynamic range, and / or increase the effective pulse frequency beyond the bandwidth of a single photoelectric converter. The outputs may be combined, for example, by connecting the outputs in series. The outputs may be combined, for example, by connecting the outputs in parallel.

[0021] The optical signal may be guided to an optical-to-electrical converter via an optical waveguide. The optical signal may be distributed to multiple optical-to-electrical converters. In one embodiment, one or more optical waveguides and one or more optical-to-electrical converters may be implemented on the same substrate.

[0022] The operation of one or more photoelectric converters may be enabled and disabled by a control signal. The operation of one or more photoelectric conversion units may be controlled, for example, by one or more control signals. Each control signal may be coupled to one or more photoelectric conversion units. The one or more control signals may enable selection of the number of active photoelectric converters that enable conversion of optical pulses into electrical pulses. The one or more control signals may enable selection of the number of disabled photoelectric converters, respectively. In particular, a first control signal may be arranged to enable and disable the operation of a first group of photoelectric converters, and a second control signal may be arranged to enable and disable the operation of a second group of photoelectric converters. The first group of converters may be connected in series with the second group of converters, for example, to improve the dynamic range of the signal.

[0023] In one embodiment, one or more optical multiplexing techniques may be used to deliver different optical pulse patterns to different optical-to-electrical converters. For example, wavelength division de-multiplexing (WDM) may be used to deliver optical pulses of different wavelengths to different optical-to-electrical converters. For example, time division multiplexing (TDM) in conjunction with wavelength division de-multiplexing (WDM) may be used to deliver optical pulses of different wavelengths to different optical-to-electrical converters.

[0024] Therefore, in a situation where the pulse frequency in a single branch is lower than the upper limit, the total pulse frequency of the optical signal may exceed the upper limit of the bandwidth of a single optical-to-electrical converter.

[0025] Some of the photoelectric converters may be biased with opposite polarities, allowing for both positive and negative output signals. The device may include multiple photoelectric converters. One or more photoelectric converters may be arranged to provide an output having a first polarity, and one or more photoelectric converters may be arranged to provide an output having a second, opposite polarity. Outputs of different polarities may be combined to provide both positive and negative output signal voltages. The outputs may be combined, for example, using photoelectric converters connected in series and / or photoelectric converters connected in parallel.

[0026] The device can include one or more photoelectric converters for converting optical pulses into electrical pulses at cryogenic temperatures, which can be, for example, a uni-traveling-carrier photodiode (UTC-PD), a plasmonic photodetector, or a superconducting nanowire single-photon detector (SNSPD).

[0027] In particular, nanowire detectors can have high efficiency for converting optical energy into electrical energy. The high efficiency of nanowire detectors can be advantageous, for example, when cooling a cryogenic chamber to temperatures below 1 K. The response curve of a nanowire detector can have a fast rise time (e.g., <50 ps) and a long fall time (>ns). The long tail of a nanowire detector's response can set an upper limit on the bandwidth of a single nanowire detector. The upper bandwidth limit can be increased, for example, by shortening the time width of the nanowire detector's response. The pulse can be shortened, for example, by clipping the tail of the response using an inverting delay line. The electrical pulse provided by a nanowire detector can be shortened, for example, by adding an inverting delay pulse to the electrical pulse.

[0028] In one embodiment, the apparatus may include a superconducting delay line for forming a delayed inverted pulse from an original voltage pulse. A first end of the delay line may act as an input for the original voltage pulse and as an output for the delayed inverted pulse. A second end of the delay line may act as a short circuit that may reflect and invert a voltage pulse propagating along the delay line. The reflected and inverted pulse may be delayed by a delay time. The delay time may be determined by the length of the transmission line of the delay line. The delayed inverted pulse may be added to the original voltage pulse after the delay time. This may allow the time width of the voltage pulse to be shortened. The time width of the shortened voltage pulse may be, for example, in the range of 10 ps to 50 ps.

[0029] By appropriately arranging the arrival times of optical pulses at a set of nanowire detectors equipped with this pulse tail clipper, it is possible to generate arbitrary pulse patterns at rates of tens of GHz. By interlacing the arrival times of optical pulses at a set of photoelectric converters, arbitrary electrical pulse patterns can be generated. The electrical output signals of the photoelectric converters can be combined to form arbitrary electrical pulse patterns.

[0030] Each photoelectric conversion unit may optionally be used in conjunction with an inverting delay line, which may be arranged to act as a pulse tail clipper.

[0031] The inverting delay line can shorten the pulse width so that the modulation frequency of any electrical pulse pattern can be, for example, 20 GHz or higher.

[0032] In one embodiment, a single succession of photons may represent a single pulse of an optical signal, and the optical signal may include multiple succession of photons at different wavelengths. The optical signal may include a first pulse at a first wavelength and a second pulse at a second, different wavelength. The apparatus may be arranged to serialize single-photon sources by wavelength into the same optical signal. The optical signal may carry information encoded in the succession of photons of the optical signal. The optical signal may include a first succession of photons at a first wavelength and a second succession of photons at a second, different wavelength.

[0033] In one embodiment, multiple nanowire detectors may be used in conjunction with one or more spectrally selective optical splitters to deserialize information guided through a single optical fiber, such that the sum of the frequencies of single photons in a single optical fiber may exceed the bandwidth of a single nanowire detector.

[0034] The signal generator may be used, for example, to provide one or more electrical waveforms for a cryogenic quantum data processor. The signal generator may be used, for example, to scale up a quantum computer.

[0035] The signal generator may be used, for example, to provide one or more electrical waveforms for quantum communication.

[0036] In one embodiment, the inverting delay line may also enable driving one or more high-speed Josephson junctions in an optical-to-electrical conversion unit that includes a superconducting nanowire single-photon detector (SNSPD). The clipping technique may also enable driving high-speed Josephson junctions in nanowire detectors (SNSPDs) in a quantized arbitrary waveform source.

[0037] In the following examples, some variants will be described in more detail with reference to the accompanying drawings. [Brief explanation of the drawings]

[0038] [Figure 1a]FIG. 1a shows, by way of example, a signal generator device. [Figure 1b] FIG. 1b shows an example signal generating device. [Figure 2a] FIG. 2a shows, by way of example, a converter unit. [Figure 2b] FIG. 2b shows, by way of example, a converter unit. [Figure 2c] FIG. 2c shows, by way of example, multiple converter units connected in series. [Figure 3a] Figure 3a shows, as an example, a converter unit including a plasmonic photodetector. [Figure 3b] Figure 3b shows, as an example, a plasmonic photodetector implemented on a waveguide in three dimensions. [Figure 4a] FIG. 4a shows, as an example, a conversion unit including a nanowire detector. [Figure 4b] FIG. 4b shows, by way of example, multiple converter units connected in parallel. [Figure 5] FIG. 5 shows, as an example, multiple converter units mounted on a substrate. [Figure 6a] FIG. 6a shows, by way of example, a converter unit and a low-pass filter. [Figure 6b] FIG. 6b shows, as an example, the conversion of light pulse frequency into voltage. [Figure 6c] FIG. 6c shows a multi-level optical signal as an example. [Figure 7a] FIG. 7a shows, as an example, a pattern generating device including multiple conversion units driven with the same optical pulse sequence. [Figure 7b] FIG. 7b shows, as an example, a signal generating device including multiple conversion units driven with different optical pulse sequences. [Figure 7c] FIG. 7c shows, by way of example, a signal generator including multiple outputs. [Figure 8a] FIG. 8a shows, as an example, a circuit for shortening an electrical pulse using an inverting delay line. [Figure 8b]FIG. 8b shows an example of an inverting delay line. [Figure 8c] FIG. 8c shows, as an example, how an inverted delayed signal is added to form a shortened pulse. [Figure 8d] FIG. 8d shows, as an example, the addition of an inverted delayed decay signal to form a shortened pulse. [Figure 9a] FIG. 9a shows, by way of example, a signal generating device that includes multiple transducers driven with different optical pulse patterns at different wavelengths. [Figure 9b] FIG. 9b shows, as an example, a signal generating device including multiple transducers driven with different optical pulse patterns at different wavelengths. [Figure 10a] FIG. 10a shows an example light pattern generating device. [Figure 10b] FIG. 10b shows an example light pattern generating device. [Figure 11a] FIG. 11a shows, by way of example, the formation of a light pulse that propagates along an arm of a light pattern generating device. [Figure 11b] FIG. 11b shows, as an example, modulating the power of a light pulse propagating along an arm of a light pattern generating device. [Figure 11c] FIG. 11c shows, as an example, how modulated pulses from the arms of a light pattern generating device are combined to form a light pulse pattern. [Figure 12] FIG. 12 shows, as an example, a light pattern generating device that provides light pulses of two different wavelengths. DETAILED DESCRIPTION OF THE INVENTION

[0039] 1a, the signal generating apparatus 1000 may include an optical pulse generating device OPG1 that generates an arbitrary optical pulse pattern OPAT1, an optical feedthrough OFEED1 that guides the optical pulse pattern OPAT1 to a cryogenic chamber VES1, and one or more photoelectric conversion units OEU1 that convert the optical pulse pattern OPAT1 into an electric pulse pattern EPAT1 in the cryogenic chamber VES1. The photoelectric conversion unit OEU1 may include an optical-to-electric converter (OEC1). The optical-to-electric converter (OEC1) may also be referred to as, for example, a photodetector.

[0040] The optical pattern generating device OPG1 may provide an optical signal CLB1 that includes an optical pulse pattern OPAT1, which may also be referred to as, for example, an optical pulse sequence.

[0041] The optical pulse pattern OPAT1 may include an optical pulse sequence with a maximum pulse repetition frequency M·f0. The maximum pulse repetition frequency (M·f0) of the optical pulse pattern OPAT1 may be high, for example, greater than 80 GHz, greater than 200 GHz, or greater than 500 GHz.

[0042] The optical signal CLB1 may include one or more sequences of optical pulses OPAT1, OPAT2. The one or more sequences of optical pulses OPAT1, OPAT2 of the optical signal CLB1 may be formed, for example, according to a primary pattern (for example, PAT0 in FIG. 11c). The optical pulse sequence OPAT1 may also be referred to as an optical pulse pattern OPAT1. The optical signal CLB1 may include one or more pulse patterns OPAT1, OPAT2. The pulse repetition rate of the optical pulses of the optical signal CLB1 may be, for example, 40 GHz or higher.

[0043] The optical pattern generating device OPG1 may include an output (OUT1) that may be coupled to the optical feedthrough OFEED1. The optical signal CLB1 may be guided from the outside of the vessel VES1 to the inside of the vessel VES1 via the optical feedthrough OFEED1. The optical signal CLB1 may be guided from the optical feedthrough OFEED1 to the photoelectric conversion unit OEU1 via the optical waveguide CWG1.

[0044] The photoelectric conversion unit OEU1 may include output nodes N1, N2 for providing an electrical output signal (V(t)), which may include an electrical pulse pattern EPAT1.

[0045] Cryogenic chamber VES1 may include a cooling system SYS1 for removing heat from the interior of the cryogenic chamber VES1. The cooling system SYS1 may transfer heat from the interior of the cryogenic chamber to the exterior of the cryogenic chamber. T1 may represent a cryogenic temperature inside the cryogenic chamber VES1. T0 may represent an ambient temperature outside the cryogenic chamber VES1.

[0046] The cryogenic temperature T1 may be, for example, lower than 20 K, lower than 5 K, or lower than 1 K. The cryogenic temperature T1 may be, for example, lower than 5 K. For example, the upper temperature limit of liquid helium is 4.2 K, and a cryogenic temperature T1 lower than 5 K can be achieved by using a cooling system SYS1 that utilizes liquid helium. For more demanding applications, the cooling system SYS1 may be arranged to maintain the cryogenic temperature T1, for example, lower than 1 K. The difference between the ambient temperature T0 and the internal cryogenic temperature T1 may be, for example, greater than 100 K. The ambient temperature T0 may be substantially equal to, for example, normal room temperature, 25°C (298 K). Different components may also be cooled to different temperatures. For example, the most critical components may be cooled to below 1 K, while less critical components may be cooled to a temperature in the range of 1 to 5 K.

[0047] Each photoelectric conversion unit OEU1 may include at least one photoelectric converter (OEC1).

[0048] The converter OEC1 can be, for example, a uni-traveling carrier photodiode (UTC-PD). A UTC photodiode can use only electrons as active carriers. The response of a UTC photodiode can have a short rise time. A UTC photodiode can achieve a bandwidth of several hundred GHz.

[0049] The converter OEC1 can be, for example, a plasmonic photodetector, which can be more energy efficient than a photodiode and can be easily integrated into silicon photonic devices.

[0050] The converter OEC1 can be, for example, a superconducting nanowire single photon detector (SNSPD). Nanowire detectors can have high efficiency, which can be advantageous, for example, when cooling the cryogenic chamber to temperatures below 1 K.

[0051] The photoelectric converter OEC1 may be, for example, a superconducting nanowire detector and may be arranged to detect single and / or multiple photons. The superconducting nanowire detector may be a superconducting nanowire single-photon detector or a structurally modified superconducting nanowire single-photon detector. The structurally modified superconducting nanowire single-photon detector may have a detection efficiency suitable for detecting multiple photons.

[0052] The apparatus 1000 may include one or more optical feedthroughs OFEED1 for directing one or more optical signals to the cryogenic chamber VES1.

[0053] 1b, the device 1000 may include two or more photoelectric conversion units OEU1, OEU2 connected in series. The combination of the photoelectric conversion units OEU1, OEU2 may have output nodes NS1, NS2. The output nodes NS1, NS2 may provide, for example, the sum (V1(t)+V2(t)) or difference (V1(t)-V2(t)) of the output voltages V1(t), V2(t) of the photoelectric conversion units OEU1, OEU2. To increase the signal level and / or widen the dynamic range, two or more converter units OEC1, OEC2 may be connected in series.

[0054] Two or more converter units OEU1, OEU2 may be connected in series such that the polarity of the second converter unit OEU2 may be opposite to the polarity of the first converter unit OEU2. As a result, output nodes NS1, NS2 may provide the difference (V1(t)-V2(t)) between the output voltages V1(t), V2(t) of the converter units OEU1, OEU2. The converter units OEU1, OEU2 may be connected in series with opposite polarities, for example, to provide positive and negative electrical pulses and / or to shorten the time width of the electrical pulses.

[0055] The light pattern generating device OPG1 may provide a first light pattern OPAT1 and a second light pattern OPAT2. The second light pattern OPAT2 may be synchronized with the first light pattern OPAT1. The first light pattern OPAT1 may be guided to a first conversion unit OEU1, and the second light pattern OPAT2 may be guided to a second conversion unit OEU2. The first conversion unit OEU1 may convert the first light pattern OPAT1 into electrical pulses to form a first output voltage V1(t). The second conversion unit OEU2 may convert the second light pattern OPAT2 into electrical pulses to form an independently controllable second output voltage V2(t). The output voltages V1(t) and V2(t) may be combined to form a combined output. For example, converter units OEU1 and OEU2 may be connected in series to provide an electrical pattern EPAT formed as the sum (V1(t)+V2(t)) of the output voltages V1(t) and V2(t) of converter units OEU1 and OEU2. For example, converter units OEU1 and OEU2 may be connected in series to provide an electrical pattern EPAT formed as the difference (V1(t)-V2(t)) of the output voltages V1(t) and V2(t) of converter units OEC1 and OEC2.

[0056] In one embodiment, the first optical signal CLB1 may include a first optical pattern OPAT1, and the second optical signal CLB2 may include a second optical pattern OPAT2. The first optical signal CLB1 may be guided from the optical pattern generating device OPG1 via a first optical feedthrough OFEED1 and via a first waveguide CWG1 to the first converter unit OEU1. The second optical signal CLB2 may be guided from the optical pattern generating device OPG1 via a second optical feedthrough OFEED2 and via a second waveguide CWG2 to the second converter unit OEU2.

[0057] In one embodiment, multiple light patterns OPAT1, OPAT2 may be transmitted in the same optical signal CLB1, for example by wavelength multiplexing, which may provide, for example, a high degree of mutual synchronization between the light patterns OPAT1, OPAT2.

[0058] Wavelength multiplexing may also make it possible to direct multiple light patterns OPAT1, OPAT2 into the cryogenic chamber VES1 through the same optical feedthrough, for example to avoid thermal power being conducted through the second feedthrough OFEED2.

[0059] In one embodiment, the timing of the pulses of pattern OPAT2 relative to the timing of the pulses of pattern OPAT1 may be selected to reduce the time width of the electrical pulses of electrical pulse pattern EPAT1.

[0060] Referring to FIG. 2a, the photoelectric conversion unit OEU1 applies a bias voltage V BIAS1 The photoelectric converter OEC1 may include a bias voltage source BIAS1 for providing a bias voltage to the photoelectric converter OEC1. The photoelectric converter OEC1 may be, for example, a plasmonic photodetector. The photoelectric conversion unit OEU1 may optionally include a resistor R1, for example for impedance matching. The waveguide or waveguide portion CWG1 may guide the optical pulse pattern OPAT1 to the photoelectric converter OEC1 of the unit OEU1.

[0061] Referring to FIG. 2b, output nodes of multiple photoelectric converters OEC1, OEC2, and OEC3 may be connected in parallel to provide a single output V1. The converters OEC1, OEC2, and OEC3 may be biased by a single bias voltage source BIAS1. The converters OEC1, OEC2, and OEC3 may be, for example, plasmonic photodetectors. Optical pulse patterns OPAT1, OPAT2, and OPAT3 may be guided to the converters OEC1, OEC2, and OEC3 via separate waveguides CWG1, CWG2, and CWG3.

[0062] Referring to FIG. 2c, a plurality of photoelectric conversion units OEU1, OEU2, and OEU3 are connected in series, and outputs V1, V2, and V3 of the conversion units OEU1, OEU2, and OEU3 are combined to generate a combined output V S1 can be formed.

[0063] 3a, each photoelectric conversion unit OEU1 may include one or more photoelectric converters OEC1, which may be, for example, plasmonic photodetectors.

[0064] The photoelectric conversion unit OEU1 may include a bias voltage unit BIAS1 for supplying a bias voltage to the photoelectric converter OEC1. The bias unit BIAS1 may supply a bias voltage for the plasmonic photodetector. The bias unit BIAS1 may be connected in series with connection nodes ND1 and ND2 of the photoelectric converter OEC1.

[0065] The operation of the photoelectric conversion unit OEU1 is controlled by, for example, a control signal S C1 can be controlled by

[0066] The optical pulses may temporarily increase the conductivity between nodes ND1 and ND2 such that conversion unit OEU1 generates a drive current pulse i1(t). The photoelectric conversion unit OEU1 may convert the optical pulse sequence OPAT1 into a drive current pulse sequence EPAT1.

[0067] Each of the photoelectric converters OEC1 and OEC2 may be optionally mounted on an optical waveguide CWG1 or CWG2, and the optical waveguides (CWG1 and CWG2) may be, for example, silicon waveguides.

[0068] FIG. 3b shows, as an example, a plasmonic photodetector OEC1 implemented on an optical waveguide CWG1. The plasmonic photodetector OEC1 may include metal structures AU1 and AU2 defining a plasmonic gap SPC1. The plasmonic gap SPC1 may be at least partially filled with a semiconductor material GE1, such as germanium. Light of the optical signal CLB1 may be coupled from the waveguide CWG1 to the plasmonic gap SPC1 by evanescent coupling to effectively interact with the semiconductor material GE1. The metal structures AU1 and AU2 may include or consist of, for example, gold. The metal structures AU1 and AU2 may be arranged to operate as output nodes ND1 and ND2 of the plasmonic photodetector OEC1. The waveguide CWG1 may be implemented on a substrate SUB1. The waveguide CWG1 may be, for example, a silicon waveguide implemented on the substrate SUB1.

[0069] Plasmonic photodetectors (OECs) can include one or more metal structures for confining light by coupling electromagnetic waves to charge carrier vibrations at the surface of the metal. The wavelength of the vibrations can be smaller than the corresponding wavelength in a vacuum. As a result, the interaction between light and matter in the subwavelength region can enable the creation of compact, high-speed photodetectors.

[0070] 4a, the converter unit OEU1 may include an opto-electrical converter OEC1 and a bias current source SUP1. The opto-electrical converter OEC1 may be a superconducting nanowire single-photon detector (SNSPD). The bias current source SUP1 may be arranged to supply a bias current to the nanowire detector OEC1.

[0071] Referring to FIG. 4b, the outputs of multiple converter units V1, V2, ... V8 may be combined to produce a composite output signal VS1 For example, the outputs may be capacitively connected in parallel to form a composite output signal V S1 The output of one or more of the converter units may optionally be inverted, for example to provide shortened pulses and / or to provide negative electrical pulses (in addition to positive pulses).

[0072] The device 1000 may optionally include a resistor R1 for impedance matching. The output of the converter unit may be, for example, capacitively connected to the resistor R1 for impedance matching.

[0073] Output signal V S1 is the filtered output signal V F1 The low-pass filter FIL1 may be optionally filtered by a low-pass filter FIL1 to provide F1 and one or more capacitive elements C F1 It can be implemented by

[0074] Referring to FIG. 5, multiple waveguides CWG1 and CWG2 and multiple conversion units OEU1 and OEU2 may be implemented on the same substrate SUB1. One or more optical pulse patterns OPAT1 of an optical signal CLB1 may be distributed to the converter units OEU1 and OEU2 via one or more optical splitters CSPL1 and multiple waveguides CWG1. The optical distribution of the one or more optical pulse patterns OPAT1 may enable spatial positions POS1 of the converter units OEU1 and OEU2 to be selected so that the length of the electrical transmission line LIN1 may be reduced or minimized. As a result, distributing the optical pulse pattern OPAT1 via multiple waveguides may enable the bandwidth of the converted electrical pulses to be increased. The position of each conversion unit may be specified, for example, by coordinates (x, y). SX, SY, and SZ may indicate orthogonal directions.

[0075] The device 1000 may include an integrated module CHIP1 that includes a plurality of photoelectric converters and a plurality of waveguides for distributing one or more optical pulse patterns to the photoelectric converters.

[0076] Two or more converter units are connected to an inductive element (L C ) can be arbitrarily connected in series.

[0077] Referring to FIGS. 6a and 6b, the output nodes N1, N2 of one or more photoelectric conversion units OEU1 may be connected to an electrical low-pass filter.

[0078] The electrical pulse pattern EPAT1 of the converter unit OEU1 is filtered at the output V F1 (t) can be low-pass filtered to provide the instantaneous voltage level V F1 The frequency (f(t)) of the existing optical pulse (logic level 1) may be proportional to the frequency (f(t)) of the existing optical pulse (logic level 1). Therefore, by selecting the frequency (f(t)) of the existing optical pulse (logic level 1), the instantaneous voltage level of the filtered output may be controlled. The signal generating device 1000 may include one or more photoelectric conversion units OEU1 and one or more low-pass filters FIL1, and converts the electrical pulse into an electrical waveform V through delta-sigma conversion at a cryogenic temperature (T1). F1 (t). The cutoff frequency of the low-pass filter FIL1 may be less than the maximum frequency of the electrical pulses (M f0). The low-pass filter may remove ultrafast signal components and may ensure that the voltage level of the output signal is proportional to the frequency of those optical pulses that represent the logic signal level 1.

[0079] Referring to Figure 6c, the modulators (MOD1, MOD2, MOD3, MOD4) of optical pattern generating device OPG1 may be arranged to provide levels other than an existing pulse (logic level 1) and a missing pulse (logic level 0). For example, each modulator may have three or more states to provide one or more intermediate signal levels in addition to a zero level (0) and a full level (1). For example, each modulator may be arranged to provide a half-level optical pulse (50%) in addition to a missing (blocked) pulse and a full-level pulse (100%).

[0080] The optical pattern generating device OPG1 may also be arranged to provide an optical signal CLB1 including two or more optical pulse patterns OPAT1, OPAT2 at different wavelengths λ1, λ2, which may also be interlaced to provide a substantially continuous envelope of the optical waveform.

[0081] The optical pulse patterns OPAT1, OPAT2 of Figure 6c can also be directed to the same photoelectric converter OEC1 to provide any electrical waveform corresponding to the combination of optical pulse patterns OPAT1, OPAT2. In this way, the present apparatus 1000 can provide any electrical waveform that may have a substantially continuous envelope without the use of a low-pass filter.

[0082] Referring to FIG. 7a, the device 1000 may include two or more converter units OEU1, OEU2 connected in series, for example, to increase the magnitude of the electrical output signal. An optical input signal CLB1 may be distributed to multiple converter units OEU1, OEU2, OEU3, and OEU4 by one or more distributors CSPL1 and optical waveguides CWG1, CWG2, CWG3, and CWG4. The arrival times of the distributed signal CLB1 at the optical-to-electrical converters may be optionally adjusted and / or synchronized using delay lines CD1, CD2, CD3, and CD4. Each delay line CD1, CD2, CD3, and CD4 may provide a propagation delay. The propagation delay of each delay line CD1, CD2, CD3, and CD4 may be selected, for example, so that optical pulses arrive at the optical-to-electrical converters of units OEU1, OEU2, OEU3, and OEU4 simultaneously.

[0083] The combination of converter units OEU1, OEU2, OEU3, and OEU4 outputs a composite electrical output signal V from output nodes NS1 and NS2 of the combination. S (t) can be provided.

[0084] Referring to FIG. 7b, the apparatus 1000 may include two or more converter units OEU1, OEU2 connected in series, for example, to provide an increased dynamic range. The optical signal CLB1 may include multiple individually selectable optical pulse patterns at different wavelengths λ1, λ2, λ3, and λ4. Different spectral components of the optical signal CLB1 may be separated using one or more spectrally selective splitters CDIC1. The separated spectral components may be directed to different converter units OEU1, OEU2, OEU3, and OEU4, which may allow, for example, changing the amplitude and / or repetition rate of the electrical pulses provided by the first converter unit OEU1 compared to the amplitude and / or repetition rate of the electrical pulses provided by the second converter unit OEU2. The separated spectral components may be directed to the different converter units OEU1, OEU2, OEU3, and OEU4 to provide multiple individually selectable arbitrary electrical waveforms (V1(t), V2(t), V3(t), and V4(t)). The converter units OEU1, OEU2, OEU3, OEU4 may be connected in series to provide the sum of the waveforms (V1(t), V2(t), V3(t), V4(t)).

[0085] The propagation delay of each delay line CD1, CD2, CD3, CD4 may be selected, for example, so that the light pulses arrive at the opto-electrical converters of units OEU1, OEU2, OEU3, OEU4 at the same time.

[0086] Alternatively, the propagation delay time of each delay line CD1, CD2, CD3, CD4 can also be selected so that the arrival times of the optical pulses at the photoelectric converters are interlaced. Interlaced arrival times can be used, for example, when guiding wavelength-demultiplexed optical pulses to multiple nanowire detectors OEC1, OEC2, OEC3, OEC4 (FIG. 9a). As a result, the (total) modulation frequency of the optical signal CLB1 can exceed the cutoff frequency of the response of each individual detector (OEC1). When the combined (sum) output of the conversion units OEU1, OEU2, OEU3, OEU4 is filtered by a low-pass filter FIL1, the interlaced arrival times can make it possible to select the cutoff frequency of the low-pass filter to be higher than the cutoff frequency of the response of each individual detector (OEC1).

[0087] Referring to FIGS. 8a to 8d, the converter unit OEU1 may include an optical-to-electrical converter OEC1, a bias current source SUP1, and an inverting electrical delay line ED1.

[0088] The photoelectric converter OEC1 can be a superconducting nanowire single photon detector (SNSPD). The response of the nanowire detector OEC1 can have a long tail (FIGS. 8c and 8d).

[0089] The bias current source SUP1 may be arranged to supply a bias current to the nanowire detector OEC1. The inverting electrical delay line ED1 may receive a voltage pulse from the output node NC1, the delay line ED1 may form an inverted delayed signal from the voltage pulse, and the inverting electrical delay line ED1 may add the inverted delayed signal to the original voltage pulse at the output node NC1. As a result, the output node NC1 may provide a shortened electrical voltage pulse (FIGS. 8c and 8d).

[0090] In one embodiment, the apparatus 1000 may include multiple photoelectric conversion units OEU1, OEU2, OEU3, and OEU4 to provide electrical pulses V1, V2, V3, and V4 from multiple different, individually controllable outputs OUT1, OUT2, OUT3, and OUT4 (FIG. 7c). The optical pulse patterns OPAT1, OPAT2, OPAT3, and OPAT4 of the optical signal CLB1 may be wavelength-selectively distributed to the different photoelectric conversion units OEU1, OEU2, OEU3, and OEU4 via waveguides CWG1, CWG2, CWG3, and CWG4.

[0091] Figure 8c shows the situation where the amplitude of the inverted delayed pulse is equal to the amplitude of the original voltage pulse.

[0092] FIG. 8c shows the situation where the amplitude of the inverted decaying delayed pulse is equal to 50% of the amplitude of the original voltage pulse.

[0093] 8b, delay line ED1 may be implemented, for example, by a superconducting wire DWIRE1, which may be surrounded by a coaxial sheath SHEATH1 to reduce electromagnetic radiation loss. A first end of the wire may be connected to node NC1. A second end of the wire may be shorted by connecting the second end to a local ground node (N2') to reflect and invert voltage pulses propagating along the delay line.

[0094] The delay line ED1 may optionally include an attenuation element ATT1 to reduce the amplitude of the inverted delayed pulse. The delay time provided by the delay line ED1 is determined by the length L of the wire DWIRE1. DELAY can be selected by selecting

[0095] The delayed inverted pulse can be added to the original pulse, for example, using resistive coupling, using inductive coupling, using capacitive coupling, or a combination thereof. For example, a resistor R D1 , R D2 A delayed inverted pulse can be added to the original pulse using

[0096] Referring to FIG. 9a, multiple photoelectric conversion units OEU1, OEU2, OEU3, and OEU4 may be capacitively connected in parallel. The spectral components of an optical signal CLB1 may be separated by a spectrally selective divider CDIC1, and the spectral components of different wavelengths λ1, λ2, λ3, and λ4 may be directed to different conversion units OEU1, OEU2, OEU3, and OEU4. As a result, each conversion unit OEU1, OEU2, OEU3, and OEU4 may provide an individually selectable electrical pulse pattern. The conversion units OEU1, OEU2, OEU3, and OEU4 combine the output voltages V1(t), V2(t), V3(t), and V4(t) of the conversion units OEU1, OEU2, OEU3, and OEU4 to generate a combined signal V S1 can be arranged to form

[0097] In one embodiment, the composite signal V S1 The maximum pulse repetition rate of the photoelectric conversion unit OEU1 may be higher than the maximum frequency determined by the response of the individual photoelectric conversion unit OEU1. In particular, each photoelectric conversion unit may include a nanowire detector (OEC1, OEC2, OEC3, OEC4).

[0098] The output pulses V1(t), V2(t), V3(t), V4(t) of the converter units OEU1, OEU2, OEU3, OEU4 can be optionally shortened, for example using an inverting delay line ED1.

[0099] Converting the spectral components at different wavelengths λ1, λ2, λ3, λ4 into electrical pulse patterns by different conversion units OEU1, OEU2, OEU3, OEU4 may make it possible to de-serialize the optical pulses of the optical signal CLB1.

[0100] In one embodiment, a single-photon pulse or a multi-photon pulse may represent a single pulse of an optical signal, and the optical signal CLB1 may include multiple consecutive photons at different wavelengths λ1, λ2, λ3, and λ4. The optical signal may include a first pulse at a first wavelength and a second pulse at a second, different wavelength. The apparatus 1000 may be arranged to serialize single-photon sources by wavelength into the same optical signal CLB1. The optical signal CLB1 may carry information encoded in the consecutive photons of the optical signal. The optical signal CLB1 may include a first consecutive photon at a first wavelength λ1 and a second consecutive photon at a second, different wavelength λ2. The nanowire detector may be used together with one or more spectrally selective optical splitters CDIC1 to deserialize information guided through a single optical fiber. Thus, the sum of the frequencies of single photons within a single optical fiber can exceed the bandwidth of a single nanowire detector (OEC1).

[0101] In one embodiment, the operation of one or more converter units OEU1, OEU2 may be enabled and disabled by a control signal. For example, the operation of converter unit OEU1 may be enabled and disabled by a control signal S SUP1 to the bias source SUP1 of the nanowire detector OEC1.

[0102] The operation of one or more photoelectric converters may be controlled by one or more control signals (S SUP1 , S SUP2 , S SUP3 , S SUP4 ) can be controlled by

[0103] The control signals may be communicated, for example, via one or more control signal lines WIRE1. The control signals may be communicated, for example, via one or more feedthroughs EFEED1 to the cryogenic chamber VES1.

[0104] In one embodiment, the bias current or voltage of the first photoelectric converter (OEC1) may be different from the bias current or voltage of the second photoelectric converter (OEC2), for example, to provide an increased dynamic range. The relative magnitude of the bias may be, for example, such that the ratio of the biases of converters identified by index k is 2 k-1 The bias voltage may be selected to be substantially equal to the bias of the first converter multiplied by .

[0105] In one embodiment, the method may include varying a photoelectric bias voltage or bias current to vary the amplitude of the generated electrical pulse.

[0106] Referring to Figure 9b, the electrical signal of the photoelectric converter may optionally be amplified by an electrical amplifier EAMP1. The output pulse may optionally be shortened, for example, by using an inverting delay line. One or more photoelectric conversion units may optionally include an electrical amplifier EAMP1 and / or an inverting delay line ED1. In particular, the photoelectric converter may be a superconducting nanowire detector.

[0107] 10a and 10b, the light pattern generating device OPG1 may, for example, generate the light pulse pattern OPAT1 by a method, which includes: - distributing a primary pulse (LB00) into a plurality of secondary pulses (LB0); - directing the secondary pulse (LB0) to propagate along different optical branches (A1, A2, A3, A4); forming a modulated optical signal (LB1) by modulating secondary pulses (LB0) propagating along different optical branches (A1, A2, A3, A4); -Different delay times (Δt D1 , Δt D2 , Δt D3 , Δt D4 ) delaying the modulated optical signal (LB1) or delaying the secondary pulse (LB0); and - forming an optical signal (LB2) by combining delayed modulated signals (LB1) from different optical branches (A1, A2, A3, A4);

[0108] The primary pulse (LB00) may be, for example, a laser pulse obtained from a laser source. The optical pattern generating device OPG1 may include, for example, a laser source for supplying the laser pulse.

[0109] The optical pattern generating device OPG1 may include one or more splitters SPL1 for splitting a primary pulse (LB00) to form a plurality of secondary pulses (LB0). The optical pattern generating device OPG1 may include one or more splitters SPL1 for splitting the primary pulse (LB00) into a plurality of secondary pulses (LB0).

[0110] The optical pattern generating device OPG1 may include an array MAR1 of modulators MOD1, MOD2, MOD3, MOD4 for forming a modulated optical signal (LB1) from the secondary pulses (LB0). The modulators may be, for example, Mach-Zehnder modulators. The secondary pulses (LB0) may be guided to the modulators via waveguides WG1, WG2, WG3, WG4.

[0111] The optical pattern generating device OPG1 generates different delay times (Δt D1 , Δt D2 , Δt D3 , Δt D4 ) The delay lines may be implemented, for example, by waveguides of different lengths.

[0112] The optical pattern generating device OPG1 may include one or more combiners CMB1 that combine delayed modulated signals (LB1) from different optical branches (A1, A2, A3, A4).

[0113] Each branch (A1, A2, A3, A4) may include an independently controllable modulator (MOD1, MOD2, MOD3, MOD4) and a delay line D1, D2, D3, D4.

[0114] The output OUT1 of the combiner CMB1 may provide an optical signal LB2 constituting any desired optical pulse pattern PAT1. The maximum pulse repetition rate of the optical pulse pattern PAT1 at the combiner output OUT1 may be equal to M·f0, where f0 denotes the repetition rate of the primary pulses (LB00) and M denotes the number of branches (A1, A2, A3, A4) feeding the combiner CMB1. The number of branches M may be, for example, in the range of 4 to 1024.

[0115] In one embodiment, the optical output signal LB2 may be coupled as an input signal CLB1 to an optical feedthrough OFEED1 of the cryogenic chamber VES1.

[0116] The optical pattern generating device OPG1 may optionally include one or more optical amplifiers (AMP3) for amplifying the optical power of the optical pulses. In one embodiment, an optical signal obtained from the output (OUT3) of the optical amplifier (AMP3) may be coupled as an input signal CLB1 to the optical feedthrough OFEED1 of the cryogenic chamber VES1.

[0117] Delay lines (D1, D2, D3, D4) may be placed between the distributor SPL1 and the modulators (MOD1, MOD2, MOD3, MOD4).

[0118] In one embodiment, the timing of the primary pulse (LB00) is determined by, for example, the synchronization signal S SYNC In one embodiment, the timing of the primary pulse (LB00) may even be traceable to the time of the atomic clock (CLK1). In one embodiment, the repetition rate of the primary pulse (LB00) may be traceable to an international standard of frequency.

[0119] The state of each modulator can be set to a pass state or a blocking state. In the blocking state, the modulator can prevent the propagation of an optical pulse. In the pass state, the modulator can allow the propagation of an optical pulse. As a result, in the pass state, the modulator can provide an existing optical pulse. In the blocking state, the modulator can provide a missing optical pulse.

[0120] The optical pattern generating device OPG1 may include a control unit PG0 for controlling the states of the modulators. The optical pattern generating device OPG1 may include a memory MEM1 for storing a primary pattern PAT0. The control unit PG0 controls the optical pattern generating device OPG1 according to the primary pattern PAT0 and according to the timing signal S SYNC The optical pattern generating device OPG1 may include one or more data processors PROC1 that provide control signals b1, b2, b3, b4 for changing the states of the modulators in accordance with the control signals b1, b2, b3, b4. The optical pattern generating device OPG1 may optionally include a drive unit DRV1 that amplifies the control signals b1, b2, b3, b4 as needed. For example, the drive unit DRV1 may provide high-voltage drive signals S1, S2, S3, S4 to the modulators based on the control signals b1, b2, b3, b4 as needed.

[0121] Each modulator may be modulated at a frequency less than or equal to the repetition rate of the primary light pulses LB00.

[0122] The maximum modulation frequency of each modulator (MOD1, MOD2, MOD3, MOD4) may be equal to the repetition rate f0 of the primary pulse (LB00). The repetition rate f0 of the primary pulse (LB00) may be, for example, less than 10 GHz, or even less than 1 GHz. Even when generating an arbitrary waveform, it is not necessary to change the state of each modulator faster than f0. As a result, the maximum pulse repetition rate of the optical pulse pattern PAT1 may be higher than the maximum modulation rate of each modulator.

[0123] Referring to FIG. 11a, the light source LS1 of the optical pattern generating device OPG1 has a repetition rate f0 (=1 / T 00) may provide a primary light pulse sequence LB00. The distributor (SPL1) may form multiple secondary pulses LB0 from the single primary light pulse LB00, and the distributor (SPL1) may direct the secondary pulses LB0 to propagate along different branches (A1, A2, A3, A4) of the optical pattern generating device OPG1. The repetition rate of the secondary pulses in each branch may be equal to the repetition rate (f0) of the primary light pulse LB00.

[0124] T 00 is a series of primary pulses LB00 k , LB00 k+1 The pulse repetition frequency f0 of the primary pulse LB00 is 1 / T 00 It can be equal to w 00 may indicate the time width of the primary pulse LB00. T0 may indicate the time width of the consecutive secondary pulses LB0 k , LB0 k+1 The pulse repetition frequency f0 of the secondary pulse LB0 may be equal to 1 / T0. The pulse repetition frequency of the secondary pulse LB0 may be equal to the pulse repetition frequency f0 of the primary pulse LB00. w0 may indicate the time width of the secondary pulse LB0. The symbol P may indicate the optical power of the pulse. d 00 may represent a propagation delay. The primary pulse LB00 may be distributed to the branches of the optical pattern generating device OPG1 to form the secondary pulse LB0.

[0125] 11b and 11c, the modulator (MOD) of each branch (A) may form a modulated optical signal from the secondary pulses LB0 arriving at the modulator (MOD) by passing the pulses or by blocking the pulses. The state of each modulator may be controlled according to a primary pattern PAT0. The primary pattern PAT0 may be read, for example, from a memory MEM1. The primary pattern PAT0 may be read, for example, from a computer-readable memory MEM1 of the control unit PG0 of the optical pattern generating device OPG1. The primary pattern PAT0 may be, for example, a value b k,1 , bk,2 , b k,3 , b k,4 , b k+1,1 , b k+1,2 , b k+1,3 , b k+1,4 The control signals S1, S2, S3, S4 can be defined by a sequence of the value b k,1 , b k,2 , b k,3 , b k,4 , b k+1,1 , b k+1,2 , b k+1,3 , b k+1,4 The state of each modulator can be set to a pass state or a blocking state according to control signals S1, S2, S3, and S4. C may indicate the time lead between reading the value of the primary pattern PAT0 and the arrival of the optical pulse at the modulator.

[0126] In one embodiment, the primary pattern PAT0 may be obtained, for example, from a data communication path. In one embodiment, the primary pattern PAT0 may be determined according to data obtained from the data communication path.

[0127] Referring to FIG. 11c, the secondary pulse LB0 or modulated signal propagating along each branch of the optical pattern generating device OPG1 has a different delay time Δt D1 , Δt D2 , Δt D3 , Δt D4 The delayed optical signals from the different branches may be combined to form an optical pulse pattern PAT1. The maximum repetition rate of the pulses of the pulse pattern PAT1 may be equal to M·f0, where M denotes the number of branches combined at the output and f0 denotes the repetition rate of the primary pulse LB00. d p may denote a propagation delay; w2 may denote an optical pulse width of the optical pulse pattern; and g3 may denote a period between successive pulses of the optical pulse pattern.

[0128] 12, the light pattern generating device OPG1 may be arranged to provide a first light pulse pattern PAT1 at a first wavelength λ1 and a second light pulse pattern PAT2 at a second wavelength λ2. The second light pulse pattern PAT2 may be synchronized and / or interlaced with the first light pulse pattern PAT1.

[0129] The generating device OPG1 may include a first light source LS1 for providing primary light pulses LB00 at a first wavelength λ1 and a second light source LS2 for providing primary light pulses LB00 at a second wavelength λ2. The operation of the second light source LS1 is controlled by a synchronization signal S SYNC can be used to synchronize the operation of the first light source LS1.

[0130] The first splitter SPL1 may form secondary light pulses LB0 from the primary pulses LB00 of the first light source LS1 and may direct the secondary light pulses LB0 to propagate along the first group of branches. The secondary pulses propagating along each branch of the first group may be modulated, delayed, and combined to form the first light pulse pattern PAT1.

[0131] The second splitter SPL2 may form secondary optical pulses LB0 from the primary pulses LB00 of the second light source LS2 and may guide the secondary optical pulses LB0 to propagate along the second group of branches. The secondary pulses propagating along each branch of the second group may be modulated, delayed, and combined to form a second optical pulse pattern PAT2. The optical pulse patterns PAT1 and PAT2 may be combined to form a wavelength-multiplexed optical signal CLB1 including the optical pulse patterns PAT1 and PAT2. The optical pattern generating device OPG1 may optionally include one or more optical amplifiers to amplify the wavelength-multiplexed optical signal CLB1.

[0132] The second splitter SPL2 may form secondary light pulses LB0 from the primary pulses LB00 of the second light source LS2. The secondary light pulses LB0 may be modulated by a second array of modulators MAR2. The second array of delay lines DAR2 may provide different delay times for different branches. The output OUT2 of the second combiner CMB2 may provide an optical signal by combining the light pulses from the different branches. The generating device OPG1 may include a delay line D for delaying the second pulse pattern PAT2 with respect to the first pulse pattern PAT1. C2 Optionally, a delay line D C2 may have an output OUT2D for providing a delayed pulse pattern.

[0133] In one embodiment, the optical pattern generating device OPG1 may also be implemented by obtaining an electrical signal, for example, from an electrical arbitrary waveform generator, and converting the electrical signal into a sequence of optical pulses, for example, by modulating the output of a laser. For example, the output of a laser diode may be modulated according to the electrical signal generated by the electrical arbitrary waveform generator. In this case, the characteristics of the optical pulses may be limited by the characteristics of the electrical signal from the electrical arbitrary waveform generator.

[0134] In one embodiment, the method may include varying the amplitude of an electrical pulse formed by converting an optical pulse into an electrical pulse. The method may include varying the amplitude of the electrical pulse, for example, by varying a bias voltage or bias current of the photoelectric conversion unit. The method may include varying the amplitude of the electrical pulse, for example, by varying the amplitude of the optical pulse. Varying the amplitude of the generated electrical pulse may provide an expanded dynamic range.

[0135] It will be apparent to those skilled in the art that modifications and variations of the devices and methods according to the present invention are perceptible. The figures are schematic. The specific embodiments described above with reference to the accompanying drawings are illustrative only and are not intended to limit the scope of the invention as defined by the appended claims.

Claims

1. Electrical waveform (V(t), EPAT1, V Ｆ１ (t)), the method comprising: - providing a first optical signal (CLB1) comprising one or more optical pulse sequences (OPAT1, OPAT2); - directing a first optical signal (CLB1) into a cryogenic chamber (VES1); - distributing the optical pulses (CLB1) of the first optical signal to two or more photoelectric conversion devices (OEC1, OEC2) via optical waveguides (CWG1, CWG2); - converting the optical pulses (CLB1) of the first optical signal into electrical pulses in a cryogenic chamber (VES1) using photoelectric conversion devices (OEC1, OEC2); forming an electrical waveform (V F1 (t)) from said electrical pulses by low-pass filtering, such that the voltage level of said electrical waveform (V F1 (t)) is proportional to the frequency of said optical pulses; The output of one or more photoelectric conversion devices (OEC1, OEC2) is connected to a resistor (R1) for impedance matching. １ ) is less than or equal to 20K, method.

2. Arbitrary electrical waveform (V(t), EPAT1, V Ｆ１ The voltage level of the optical pulse (V(t), EPAT1, V(t)) is proportional to the frequency of the optical pulse. Ｆ１ 10. The method of claim 1, comprising forming (t).

3. 3. The method according to claim 1, wherein the optical waveguides (CWG1, CWG2) are mounted on a substrate (SUB1).

4. The following methods: - distributing a primary pulse (LB00) to form a plurality of secondary pulses (LB0); - different optical branches (A １ , A ２ directing a secondary pulse (LB0) to propagate along the - different optical branches (A １ , A ２ forming a modulated optical signal (LB1) by modulating a secondary pulse (LB0) propagating along the - Different delay times (Δt Ｄ１ , Δt Ｄ２ ) delaying the modulated optical signal (LB1) or delaying the secondary pulse (LB0); - different optical branches (A １ , A ２ forming an optical signal (LB2) by combining delayed modulated optical signals (LB1) from the 4. The method of claim 1, further comprising forming an optical signal (CLB1) by a method comprising:

5. An electric waveform (V) obtained by low-pass filtering from electric pulses obtained from one or more photoelectric conversion devices (OEC1) Ｆ１ The method of any one of claims 1 to 4, comprising forming (t)).

6. The method according to any one of claims 1 to 5, comprising obtaining electrical pulses from two or more photoelectric conversion devices (OEC1, OEC2) connected in series.

7. The method according to any one of claims 1 to 6, wherein the pulse repetition rate of the optical pulses of the first optical signal (CLB1) is higher than 40 GHz.

8. Directing a first sequence of optical pulses (OPAT1) of a first optical signal (CLB1) to a first photoelectric conversion device (OEC1); directing a second sequence of optical pulses (OPAT2) of the first optical signal (CLB1) to a second photoelectric conversion device (OEC2); and converting the first sequence of optical pulses (OPAT1) into a first voltage pulse (V) using the first photoelectric conversion device (OEC1). １ (t)), and converting the second sequence (OPAT2) of light pulses (OPAT2) into second voltage pulses (V ２ (t)), the method comprising: １ (t)) as a second voltage pulse (V ２ (t)) to obtain a composite signal (V Ｓ１ The method of any one of claims 1 to 7, comprising forming (t).

9. Directing a first sequence of optical pulses (OPAT1) of a first optical signal (CLB1) to a first photoelectric conversion device (OEC1); directing a second sequence of optical pulses (OPAT2) of the first optical signal (CLB1) to a second photoelectric conversion device (OEC2); and converting the first sequence of optical pulses (OPAT1) into a first voltage pulse (V) using the first photoelectric conversion device (OEC1). １ (t)), and converting the second sequence (OPAT2) of light pulses (OPAT2) into second voltage pulses (V ２ (t)) and a first voltage pulse (V １ (t)) from the first output (OUT1); and providing a second voltage pulse (V ２ and (t)) providing the signal from the second output (OUT2).

10. The first sequence (OPAT1) is at a first wavelength (λ １ ), and a second sequence (OPAT2) has a second different wavelength (λ ２ 10. The method of claim 8 or 9, wherein

11. 11. The method according to any one of claims 1 to 10, wherein the light pulses are converted into electrical pulses using one or more superconducting nanowire detectors (OEC1) arranged to detect single and / or multiple photons.

12. An electric waveform (V Ｓ１ (t), EPAT1), and the operation of at least one photoelectric conversion device (OEC1, OEC2) is controlled by a control signal (S ＳＵＰ１ 12. The method of claim 1, wherein the method is selectively enabled and disabled by

13. A method according to any one of claims 1 to 12, comprising shortening the duration of the electrical pulse by applying a delayed inversion pulse.

14. An apparatus (1000), comprising: an optical pattern generating device (OPG1) providing a first optical signal (CLB1) comprising one or more optical pulse sequences (OPAT1, OPAT2); - a cryogenic chamber (VES1); - Internal temperature of the cryogenic chamber (VES1) (T １ a cooling system (SYS1) arranged to keep the temperature of the heating element (H) below 20 K; an optical feedthrough (OFEED1) that directs the first optical signal (CLB1) into the cryogenic chamber (VES1); one or more splitters (CSPL1) for splitting the optical pulses of the first optical signal (CLB1) via optical waveguides (CWG1, CWG2) to two or more photoelectric conversion devices (OEC1, OEC2); - The optical pulse of the first optical signal (CLB1) is converted into an electric pulse (V １ (t)) and one or more photoelectric conversion units (OEU1); Equipped with the device (1000) is arranged to form the electrical waveform (V F1 (t)) from the electrical pulses by low-pass filtering such that the voltage level of the electrical waveform (V F1 (t)) is proportional to the frequency of the optical pulses; The apparatus (1000) has outputs of one or more photoelectric conversion devices (OEC1, OEC2) connected to a resistor (R1) for impedance matching.

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