Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-3 and 5 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Caspar et al (from IDS filed on 1/23/2025).
Regarding claim 1, Caspar discloses a circuit (see the schematic of the experimental setup in Fig. 2 on page 3) comprising:
a first heralded single photon source operable to produce a pair of first photons (see the PPLN crystal producing photons λs and λi), the first heralded single photon source having a first signal output path to receive a first photon of the pair of first photons and a first herald output path to receive a second photon of the pair of first photons (see the separation of photon λs and λi on the beam splitter and sent into two fibers; “signal and idler modes are separated after their generation at the polarizing beam splitters (PBS) and coupled into single-mode optical fibers”, page 3, section Experiment, left-hand column);
a second heralded single photon source operable to produce a pair of second photons (see the PPKTP crystal producing photons λs and λi), the second heralded single photon source having a second signal output path to receive a first photon of the pair of second photons and a second herald output path to receive a second photon of the pair of second photons (see the separation of photon λs and λi on the beam splitter and sent into two fibers);
a mode coupling optical circuit coupled between the first herald output path and the second herald output path, the mode coupling optical circuit having a first mode-coupling output path and a second mode-coupling output path (see Fig. 2; “the idler photons are then sent to a 50/50 beam splitter (BS)”);
a first detector configured to detect photons from the first mode-coupling output path (see the SNSPD post the EOM in Fig 2; “photons are detected by three superconducting nanowire single-photon detectors (SNSPD)”, page 3, caption to Fig. 2);
a second detector configured to detect photons from the second mode-coupling output path (see the PD in Fig. 2; “a piezoelectric fiber stretcher (PZT) with a half-wavelength voltage of V
π
1
4
0.18
V
a
n
d
a
n
d
a
n
optical delay range of about 0.57 ps is actively controlled such that the seed power at the second output port of the 50/50 BS, measured with a photodiode (PD), is maximized”, page 4, left-hand column, first paragraph); and
a classical decision logic circuit coupled to the first detector and the second detector and configured to determine whether a photon was detected on exactly one of the first mode-coupling output path and the second mode-coupling output path and to generate a success signal indicating whether a photon was detected on exactly one of the first mode-coupling output path and the second mode-coupling output path (“in order to certify the entanglement, we use an entanglement witness which does not rely on postselection”, page 1, abstract; “the detection of a single photon at the central station erases the which-path information about which one of the two photon pair sources it was emitted from, and heralds the distributed entangled state”, page 2, right-hand column, second paragraph).
Regarding claim 2, the circuit of claim 1 wherein the first heralded single photon source is configured such that the first photon of the pair of first photons has a first frequency (λs 1541.3nm) and the second photon of the pair of first photons has a second frequency different from the first frequency (λi 1546.1 nm, see Fig. 2 and page 3, left-hand column, section Experiment).
Regarding claim 3, the circuit of claim 2 wherein the second heralded single photon source is configured such that first photon of the pair of second photons has a third frequency (λs 1530 nm) and the second photon of the pair of second photons has the second frequency (λi 1546.1 nm, see Fig. 2 and page 3, left-hand column, section Experiment).
Regarding claim 5, the circuit of claim 3 wherein the first frequency and the third frequency are the same frequency (λs 1530 nm, see Fig. 2 and page 3, left-hand column, section Experiment).
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 5 is rejected under 35 U.S.C. 103 as being unpatentable over Caspar et al (from IDS filed on 1/23/2025).
Caspar discloses the claimed invention as set forth above except for wherein the first frequency and the third frequency are different frequencies.
It would have been obvious to one having ordinary skill in the art at the time of invention before the effective filing date to make the first and the third frequency that are different for the purpose of obtaining data density by packing different frequences.
Allowable Subject Matter
Claims 6-23 are allowed.
The following is an examiner’s statement of reasons for allowance:
Claims are allowable at least for the reason that the prior art does not teach or reasonably suggest the digital logic output signal path determines whether exactly one photon is present on the first and second output paths and a mode coupler network having at least four inputs and at least four outputs, the number of outputs being equal to the number of inputs, the mode coupler network being configured such that a photon received on any one of the inputs has an equal probability of being output on any one of the outputs as set forth in the claimed combination.
Dhara Prajit et al (from IDS filedon 7/30/2026) discloses a circuit (see Fig. 1) comprising:
a plurality of heralded single photon source pairs (see the plurality of cascaded sources in Fig. 1, each cascaded source containing two sources as shown in Fig. 3; page 2, right-hand column, last paragraph); wherein each heralded single photon source pair has a first output optical path, a second output optical path, and a digital logic output signal path, wherein each heralded single photon source pair is configured to generate photons on the first and second output paths (see the output state by the original source in Fig. 2; see the output paths to state S and the heralding trigger signal in Fig. 3; “the four-mode output state … two output pulses)”, page 4, left-hand column, last paragraph), to determine photon is present on the first and second output paths without determining on which of the first and second output paths the photon is present, and to output a success signal on the digital logic output signal path, the success signal indicating whether photon is present on the first and second output paths (see the “desirable” click pattern for the four PNR detectors described on page 5, left-hand column in particular the table. The PNR detectors must detect two clicks to result in the desire state as described in section II.B on page 5, left-hand column; “depending upon which of the four desirable click patterns occur on the four PNR detectors … “page 5, right hand column); and
a classical decision logic circuit coupled to the detectors and configured to determine, based on signals received from the detectors, whether a target entangled state of a number n of qubits is present on a number 2n of the first output optical paths, wherein n is an integer greater than or equal to 2 (“Furthermore, we say that the source was “successful “ … (0011 or 1100) occur” page 5 last paragraph of left-hand column gonging onto the right-hand column; the corresponds to the creation of a Bell state in a cascaded source with 4 output paths and n-2, see Fig. 3 and equation 5).
However, the prior art does not disclose the digital logic output signal path determines whether exactly one photon is present on the first and second output paths and a mode coupler network having at least four inputs and at least four outputs, the number of outputs being equal to the number of inputs, the mode coupler network being configured such that a photon received on any one of the inputs has an equal probability of being output on any one of the outputs as set forth in the claimed combination.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to EUNCHA P CHERRY whose telephone number is (571)272-2310. The examiner can normally be reached M to F 7am to 3:30pm.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Pinping Sun can be reached at (571) 270-1284. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
8/29/2026
/EUNCHA P CHERRY/ Primary Examiner, Art Unit 2872
