DETAILED ACTION
Claim Objections
Applicant is advised that should claim 11 be found allowable, claim 15 will be objected to under 37 CFR 1.75 as being a substantial duplicate thereof. When two claims in an application are duplicates or else are so close in content that they both cover the same thing, despite a slight difference in wording, it is proper after allowing one claim to object to the other as being a substantial duplicate of the allowed claim. See MPEP § 608.01(m).
Re claim 15, the claim recites ‘”An optical system for quantum communication comprising an optical transmitter and an optical receiver according to claim 11”. However, claim 11 recites “An optical receiver for quantum communication, comprising:
a detection unit containing one or more photon counters arranged and configured to detect QKD encoded pulses emitted by the optical transmitter according to claim 1”, such that the limitation requires the transmitter according to claim 1 and therefore requires all the limitation within claim 1 as well as those recited within claim 11. Hence, the recitation of a quantum communication system comprising and optical transmitter and an optical receiving according to claim 11 does not comprise any new limitation such that the claim scopes are essentially the same and therefore and substantial duplicates of each other.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 1, 2, 6, 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Dynes et al (wherein Dynes) US PG PUB 2015/0372768 and Trifonov US PG PUB 2009/022322.
Re claim 1, Dynes discloses an optical transmitter for quantum communication (quantum communication system), comprising:
a QKD channel comprising at least one QKD light source and configured to emit a stream of QKD encoded pulses (light source 2 is part of a GHZ clock QKD system ¶ [0058] that generates short pulses ¶ [0030];
a reference channel comprising a reference light source and configured to emit a stream of reference pulses (a through coupler splits the incoming light pulse into two paths ¶ [0030], such that the coupler generates from the QKD pulses a reference pulse); and
a control circuit connected to the QKD channel and to the reference light channel, wherein the control circuit is configured to control the QKD channel and the reference channel to emit the reference pulses with a predetermined time delay to the QKD encoded pulses (coupler 4 splits the incoming light pulses into two paths. The first path comprises a longer arm of the interferometer using an optical delay loop 5. The shorter path comprises a phase modulator that is used to encode random (key) information on onto the light pulses. Due to the variation of the length of the arms. The light pulses 7 that follow the short path and the light pulses 8 that follow the long path have a temporal separation Dt ¶ [0031], such that the system of the system is imparting the time delay on the encoder), and
wherein a difference of a wavelength of the QKD encoded pulses and a wavelength of the reference pulses is 5 nm or less (within the system of Dynes, the encoded pulses and the reference pulse and generated from the same laser source, such that the wavelength is the same such that their wavelengths are understood to be 5 nm or less as they are the same).
Dynes does not explicitly the disclosure of the QKD source as well as the reference channel comprising a reference light source, such that there are two light source. However, Trifonov discloses wherein the optical transmitter of Charlie discloses wherein there are two sources including a pump laser 22 and a “reference” laser 24. ¶ [0018] Additionally, it is disclosed that laser 24 is included in system 20, wherein in an example embodiment the wavelength l 24 of laser 24 is the same as or very close to (i.e., substantially the same as) wavelength l 22 of pump laser 22 and entangled photons P$. In a particular example embodiment, wavelength l 24 of laser 24 is shifted by one or more channels, say, by a few channels and thus a total of a few nanometers, with respect to wavelength l 22 of pump laser 22 and entangled photons P5 ¶ [0039], such that there are approximately the same wavelength and only a few nm would also read upon less than 5 nm.
Dynes and Trifonov are analogous art because they are from the same field of endeavor, quantum key communication systems. At the time filing, it would have been obvious to one of ordinary skill in the art, having the teachings of Dynes and Trifonov before him or her, to modify the generation of the reference signal of Dynes to include the ability to generate the reference pulse through its own light source as disclosed by Trifonov because it combines prior art elements, according to known methods to yield predictable results, in this case, enabling the system to generate the desired pulses for each system along the desired wavelength and distinguish the signals if necessary.
Re claim 2, Dynes and Trifonov disclose all the elements of claim 1, which claim 2 is dependent. Furthermore, Dynes and Trifonov discloses wherein the control circuit comprises a pulse generator, and wherein the control circuit is configured to drive the reference light source by pulses generated by the pulse generator (Trifonov discloses control circuit activates laser 24 via an activation signal S2 to case light pulses P2 to be generated and multiplexed with light pulses P0 ¶ [0032], such that the control unit generates the pulse or signal S2 to generate the pulse from the reference signal).
Re claim 6, Dynes and Trifonov disclose all the elements of claim 1, which claim 6 is dependent. Furthermore, Dynes discloses further comprising combiner optics arranged and configured to combine the QKD encoded pulses and the reference pulses to a combined output beam (the pulses are combined at the polarizing beam splitter 9 ¶ [0032], such that both of the pulses are combined).
Re claim 9, Dynes and Trifonov disclose all the elements of claim 1, which claim 9 is dependent. Furthermore, Dynes disclose wherein the predetermined time delay is approximately half of a time period of two successive QKD encoded pulses (the temporal separation may be set to ½ the inverse clock rate of the QKD system ¶ [0032], such that the clock would that which defines the period of the QKD pulses).
Claim(s) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Dynes and Trifonov as applied to claim 1 above, and further in view of Li et al (herein Li) US PG PUB 2020/0169397.
Re claim 3, Dynes and Trifonov discloses all the elements of claim 1, which claim 3 is dependent. Furthermore, while the prior art of Dynes and Trifonov discloses a laser system to generate the pulse and discloses the use of a control circuit C to control or generate said pulse. However, Trifonov does not explicitly disclose a plurality comprising an amplitude modulator connected to the control circuit, wherein the reference light source is configured as a cw light source, wherein the amplitude modulator is arranged in the reference channel and configured to modulate emitted light of the reference light source to generate the reference pulses. However, Li discloses wherein the step of modulating a continuous light source to generate a pulse light, wherein the continuous light source is modulated to be a pulse light through amplitude modulators ¶ [0018].
Dynes, Trifonov, and Li are analogous art because they are from the same field of endeavor, quantum key distribution communication systems. At the time filing, it would have been obvious to one of ordinary skill in the art, having the teachings of Trifonov and Li before him or her, to modify the laser or light source of Trifonov to include the use of a continuous laser alongside amplitude modulators to generate pulses of Li because it combines prior art elements, according to known methods, to yield predictable results, in this case, generate the desired pulsed signals from a light source.
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Dynes and Trifonov as applied to claim 1 above, and further in view of Wang et al (herein Wang) US PG PUB 2008/0292102.
Re claim 4, Dynes and Trifonov disclose all the elements of claim 1, which claim 4 is dependent. Furthermore, Dynes discloses the delay to be induced via an optical delay loop and does not explicitly disclose wherein the control circuit comprises a reference delay line configured to delay an electric signal to the reference channel to generate the predetermined time delay.
However, Wang discloses that one hardware implementation that may be used is an electrical circuit having one or more capacitors to provide the delay. Physical delay lines such as optical fibers and electrical cables may also be used to provide the delay ¶ [0068].
Dynes, Trifonov, and Wang are analogous art because they are from the same field of endeavor, QKD systems. At the time filing, it would have been obvious to one of ordinary skill in the art, having the teachings of Dynes, Trifonov, and Wang before him or her, to modify the circuit to provide the delay of Dynes to include the electrical cables of Wang because it combines prior art elements, according to known methods, to yield predictable results, in this case, enabling the imparting of a delay through the electrical circuit rather than optically.
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Dynes and Trifonov as applied to claim 1 above, and further in view of Franson et al (herein Franson) US PG PUB 2004/0109631.
Re claim 5, Dynes and Trifonov disclose all the elements of claim 1, which claim 5 is dependent. Furthermore, Dynes discloses that the light source could generate short light pulses which are linearly polarized, but does not explicitly disclose the system further comprising a spatial mode converter, which is configured to modulate a spatial mode of at least one of the QKD encoded pulses or the reference pulses.
However, Franson discloses that “embodiments of the invention may be used where qubits are represented by the polarization state of single photons. It is well known that a qubit represented by polarization states of a photon can be converted to a qubit represented by presence or absence in a particular spatial mode by passing the photon through a polarizing beam splitter. Similarly, a qubit represented by presence or absence in a particular spatial mode can be converted to a qubit represented by polarization states by passing the photon in the particular spatial mode through a rotator that rotates the photon to a first polarization representing a first basis state, e.g., a horizontal polarization; and by passing a photon in the complimentary spatial mode through a rotator that rotates the photon to a second, orthogonal polarization representing a second basis state, e.g., a vertical polarization: ¶ [0038].
Dynes, Trifonov, and Franson are analogous art because they are from the same field of endeavor, QKD systems. At the time filing, it would have been obvious to one of ordinary skill in the art, having the teachings of Dynes, Trifonov, and Franson before him or her, to modify the transmission of transmitter the Dynes and Trifonov to include the spatial mode converters, such as a polarization rotator of Franson because it combines prior art elements, according to known methods, to yield to predictable results.
Claim(s) 7 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Dynes and Trifonov as applied to claim 1 above, and further in view of Williams et al (herein Williams) US PG PUB 2023/0020193 and Wang US PG PUB 2009/0106553.
Re claim 7, Dynes and Trifonov disclose all the elements of claim 1, which claim 7 is dependent. Furthermore, Dynes discloses that the pulses are attenuated to the single photon level using an optical attenuator 12 resulting in single photon pulses 13 and 14 before being emitted from the transmitter to an optical channel 16 ¶ [0032], such that the signals are attenuated to an single photon.
Additionally Wang discloses most practical QKD systems to date employ a multi-photon source, such as a laser, and attenuate multi-photon pulses to achieve single-photon quantum signals to a level 0.1 or 0.2 photon per pulse ¶ [0026].
Dynes and Wang are analogous art because they are from the same field of endeavor, QKD communication systems. At the time filing, it would have been obvious to one of ordinary skill in the art, having the teachings of Dynes, Trifonov, and Wang before him or her, to modify the optical source of Dyne and Trifonov, to include the attenuator at the source to make it a single photon source of Wang because combines prior art elements, according to known methods, to yield predictable results, in this case, enabling the generation of a QKD source.
Dynes does not explicitly disclose wherein the OKD Channel comprises a plurality of QKD light source. However, Williams disclose that a key distribution layer includes a plurality of quantum key distribution source, which each QKD source distribution an identical set of keys to each of the QA servers using a group quantum key distribution or multi-casting QKD protocol in a quantum safe manner.
Dynes and William are analogous art because they are from the same field of endeavor, QKD systems. At the time filing, it would have been obvious to one of ordinary skill in the art, having the teachings of Dynes and Williams and before him or her, to modify the transmitter of Dynes to include the plurality of QKD sources of Williams because it combines prior art elements, according to known methods, to yield predictable results, in this case, enabling the multi-casting of QKD.
Re claim 8, Dynes, Trifonov, Wang, and Williams disclose all the elements of claim 7, which claim 8 is dependent. Furthermore, the combination of Dynes and Williams discloses the replication of QKD sources in order to multi-cast the QKD system to a plurality of servers, such that the combination would result in a multiplication of the QKD of Dynes. Hence, are a result of the combination, Dynes and Williams would disclose wherein the control circuit comprises a QKD delay line for each of the QKD light sources, and wherein the control circuit is configured to trigger the plurality of QKD light sources to substantially emit QKD encoded pulses simultaneously (Dynes discloses that the delay in introduce by the interferometer having a delay loop along one path and the combination alongside Williams would suggest a replication of this transmitter such that there are a plurality of these delay loops for each transmitter. Additionally, as according to Dynes, the reference pulse and the pulses to be QKD encoded are from the same source, they are essentially generate simultaneously, such that the combination of Dynes and Trifonov would teach the generation of the reference pulse and the encoded pulse to be simultaneous to replicate that of Dynes).
Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Dynes and Trifonov as applied to claim 1 above, and further in view of Schlafer et al (herein Schlafer) US PG PUB 2005/0190921.
Re claim 10, Dynes and Trifonov disclose all the elements of claim 1, which claim 10 is dependent. Furthermore, Dynes and Trifonov does not explicitly disclose wherein the control circuit comprises an internal clock, wherein the internal clock is configured to provide a time base for the predetermined time delay of the QKD encoded pulses and the reference pulses.
However, Schlafer discloses within the QKD transmitter 605 within Fig. 7, the use of a QKD source 705 and the bright source 755 to make the reference pulse. Additionally, a series of trigger values may be received from clock source 763 for triggering pulse generator 749. When triggered, pulse generator 749 may send an output electrical pulse that is split, via signal splitter 747, into two identical pulses. One of the pulses from signal splitter 747 may drive QKD source 705, and another of the pulses from signal splitter 747 may pass through delay unit 751 and switch 753 to drive bright source 755. ¶ [0042]
Dynes, Trifonov, and Schlafer are analogous art because they are from the same field of endeavor, QKD transmitters. At the time filing, it would have been obvious to one of ordinary skill in the art, having the teachings of Dynes, Trifonov, and Schlafer before him or her, to modify the transmitter circuitry to control the system of Dynes and Trifonov to include the elements of the delay unit and a pulse generator to simultaneous generate the pulse of the QKD source and reference pulses of Schlafer because it combines prior art elements according to known methods, to yield predictable results, in this case, reduces the need to have the optical delay and implemented a simple single source trigger or pulse for both lights and imputing the delay within the electrical circuitry of the system rather than the optical system.
Allowable Subject Matter
Claims 11-14 objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim 16 allowed.
The following is a statement of reasons for the indication of allowable subject matter:
Re claim 11, the claim recites “An optical receiver for quantum communication, comprising:
a detection unit containing one or more photon counters arranged and configured to detect QKD encoded pulses emitted by the optical transmitter according to claim 1;
a wavefront sensor arranged to receive reference pulses emitted by the optical transmitter, and configured to measure a wavefront of the reference pulses to provide a wavefront signal;
an adaptive optical element arranged upstream of the detection unit and configured to manipulate a wavefront of the QKD encoded pulses; and
a receiver controller connected to the wavefront sensor, the adaptive optical element and the detection unit, wherein the receiver controller is configured to:
apply a time gate to the one or more photon counters in the detection unit at a time of arrival of the QKD encoded pulses; obtain the wavefront signal indicating the measured wavefront of the reference pulses; and trigger the adaptive optical element to correct the wavefront of the QKD encoded pulses based on the wavefront signal.”
Dynes and Trifonov disclose all the limitation such that it discloses the system that enables the transmission of the QKD encoded pulses. Additionally Dynes does disclose a detector or receives of the system. Additionally there are other components with the system that are able to be interpreted as “a wavefront sensor arranged to receive reference pulses emitted by the optical transmitter, and configured to measure a wavefront of the reference pulses to provide a wavefront signal and an adaptive optical element arranged upstream of the detection unit and configured to manipulate a wavefront of the QKD encoded pulses”. For example, Dynes discloses measuring, by a wavefront sensor, a wavefront of the reference pulses (The optical pulses travel down optical channel 16 which could be an optical fiber link. The pulses then enter receiver 17. The receiver comprises an asymmetric MZI, which in this case functions as a decoder with a pair of single photon detectors 31 and 32 ¶ [0033], such that the photon detectors that receive the pulses include receiving the reference pulse);
applying, based on the measured wavefront, a wavefront correction to the QKD encoded pulses by an adaptive optical element (fine tuning of the interference may be performed by adjusting the phase of the light pulse in the long arm using fibre stretcher 28 via controller 34. This compensates small (phase) changes in the interferometers due to thermal drifts. ¶ [0037], such that it modifies the reference pulse to change and would affect the detection of the QKD encoded pulses when they are recombined).
However, thee combined prior art combination does not disclose of “a receiver controller connected to the wavefront sensor, the adaptive optical element and the detection unit, wherein the receiver controller is configured to:
apply a time gate to the one or more photon counters in the detection unit at a time of arrival of the QKD encoded pulses;
obtain the wavefront signal indicating the measured wavefront of the reference pulses; and
trigger the adaptive optical element to correct the wavefront of the QKD encoded pulses based on the wavefront signal.” Additionally, the examiner was unable to find, alone or in combination, the teaching of a QKD encoded system wherein the use of a temporal gate or time gate is found within the receiver, such as to be use at the time of arrival of the QKD encoded pulses alongside of the triggering of adaptive optical element to correct the wavefront of the QKD encoded pulses based on the wavefront signal. Hence, when the claim scope is considered as a whole, the claim is considered allowable.
Re claims 12-14, these claims are dependent upon claim 11 and are allowable for the reasons previously stated.
Re claim 16, many of the limitation are disclosed by the prior art of Dynes (US PG PUB 2015/0372769) discloses a method for quantum communication, comprising:
emitting, by an optical transmitter, a stream of QKD encoded pulses and reference pulses (First, the light pulses on entering MZI pass through coupler 4 that splits the incoming light pulses into two paths. ¶ [0031], such that one path is the reference pulse and the other is to be the QKD encoded pulses), wherein the reference pulses are emitted with a predetermined time delay to the QKD encoded pulses (In this example, the first path comprises a longer arm of the interferometer using an optical delay loop 5. The second, shorter path comprises a phase modulator 6. The phase modulator is used to encode random (key) information onto the light pulses. Due to the variation in the length of the arms, the light pulses 7 that follow the short path and the light pulses 8 that follow the long path have a temporal separation Δt ¶ [0031], such that the reference pulses experience a delay via the delay loop 5 from the QKD encoded pulses), wherein a difference of a wavelength of the QKD encoded pulses and a wavelength of the reference pulses is 5 nm or less (as both pulses are generated from splitting the same light source, they are of the same wavelength and the difference between the wavelengths of the QKD pulses and the reference pulses is less than 5 nm as they should be exactly 0);
measuring, by a wavefront sensor, a wavefront of the reference pulses (The optical pulses travel down optical channel 16 which could be an optical fiber link. The pulses then enter receiver 17. The receiver comprises an asymmetric MZI, which in this case functions as a decoder with a pair of single photon detectors 31 and 32 ¶ [0033], such that the photon detectors that receive the pulses include receiving the reference pulse);
applying, based on the measured wavefront, a wavefront correction to the QKD encoded pulses by an adaptive optical element (fine tuning of the interference may be performed by adjusting the phase of the light pulse in the long arm using fibre stretcher 28 via controller 34. This compensates small (phase) changes in the interferometers due to thermal drifts. ¶ [0037], such that it modifies the reference pulse to change and would affect the detection of the QKD encoded pulses when they are recombined).
However, the prior art of Dynes does not explicitly disclose obtaining, by a detection unit containing one or more photon counters, the QKD encoded pulses by applying a time gate based on a time of arrival of the QKD encoded pulses at the one or more photon counters in the detection unit for temporally filtering the QKD encoded pulses from the reference pulses. Dynes does disclose the use of a temporal gate system, but rather then temporal filter is used at the transmitter end, rather than the receiver end. Hence, the discourse of the temporal gate at the receiver, such as to separate the reference pulses from the QKD encoded pulses. Rather, the two types of pulse could be separated in Dynes through the polarization state or rather, by potentially of the wavelength as disclosed through other prior art of Trifonov which discloses the use of potential of wavelengths rather than temporal filtering. Hence, when the claim scope is considered as a whole, the claims are considered allowable.
Conclusion
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TANYA MOTSINGER
Examiner
Art Unit 2637
/TANYA T MOTSINGER/ Examiner, Art Unit 2635