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Tutorial: Hong-Ou-Mandel interference with Structured Photons

T0 review · 3 major / 3 minor · reviewed 2026-08-10 · deepseek-v4-flash

Pith's one-line read This tutorial derives exact formulas for Hong-Ou-Mandel interference of structured photons, showing the coincidence rate depends only on mode overlaps and giving a closed-form expression for Laguerre-Gauss mode overlaps with different…

desk verdict Useful tutorial with a correct LG overlap formula, but Eq (27) has a factor-of-2 error and Eq (21) overclaims arbitrary-mode validity because it ignores the OAM sign flip; the stress-test's bucket-detector counterexample is wrong. read the letter →

arxiv 2501.14961 v1 pith:EHOCMMOH submitted 2025-01-24 quant-ph physics.optics

classification quant-phphysics.optics
keywords Hong-Ou-MandelinterferencestructuredphotonsspatialmodesLaguerre-Gaussorbitalangularmomentumtwo-photonHOMvisibilityclosed-formoverlap
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This tutorial establishes a general theoretical framework for Hong-Ou-Mandel interference between two photons that carry arbitrary spatial mode profiles. It derives a master formula for the coincidence rate after the beamsplitter for any choice of detection projections, and shows that in the common bucket-detector case the rate reduces to one minus the squared overlap of the two input modes. The paper also produces a closed-form expression for the overlap of any two Laguerre-Gauss modes with different beam waists and propagation distances, replacing a numerical two-dimensional integral with a direct evaluation. These results matter because they make exact simulation of structured-photon interference practical, which is a necessary component for computational discovery of new quantum optical experiments.

What carries the argument

The central object is the antisymmetrized product of modal amplitudes $\psi_{1,\gamma'}\psi_{2,\gamma} - \psi_{1,\gamma}\psi_{2,\gamma'}$ that appears in the coincidence amplitude; it encodes both the two-photon path interference and the spatial-mode content of the measurement. The derivation relies on a mode-independent 50:50 beamsplitter transformation (Eq. 15) and projective detection operators with binary weights $p_\gamma$ (Eq. 17). The analytic workhorse is the closed-form integral for the overlap of two Laguerre-Gauss modes with distinct waists and propagation distances (Eq. 34), expressed as a Gauss hypergeometric function ${}_2F_1$; this converts a two-dimensional numerical quadrature into a direct evaluation, which is what makes fast simulation of structured-photon networks possible.

What would settle it

Evaluate Eq. (34) for two Laguerre-Gauss modes with indices $\ell=2$, $p=p'=3$, waist ratio $w_0'/w_0 = 1.2$, and relative propagation distance $z' - z = 0.3 z_0$, and compare the closed-form value against high-precision numerical quadrature of the defining integral (Eq. 32); any mismatch would falsify the closed-form overlap claim. On the experimental side, measuring the bucket-detector HOM rate for the same two modes and comparing it with $\tfrac{1}{2}(1-|(\text{LG}|\text{LG}')|^2)$ would test the mode-independence of the beamsplitter, since a deviation would signal mode-dependent reflectivity or breakdown of the paraxial model.

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Extended reading notes

Core claim

On its own terms, the paper claims that for two frequency-degenerate photons entering the two ports of a 50:50 beamsplitter, with one photon in spatial mode $\psi_1$ and the other in mode $\psi_2$, the coincidence rate after projecting the outputs onto arbitrary mode sets is exactly $\mathcal{R}_{c,d} = \tfrac{1}{4}\sum_{\gamma,\gamma'} p^{(c)}_\gamma p^{(d)}_{\gamma'} |\psi_{1,\gamma'}\psi_{2,\gamma} - \psi_{1,\gamma}\psi_{2,\gamma'}|^2$ (Eq. 21). When both detectors are bucket detectors that accept all modes, this specializes to $\mathcal{R}_{c,d} = \tfrac{1}{2}(1 - |(\psi_1|\psi_2)|^2)$, so the depth of the HOM dip directly measures the spatial overlap of the input modes. When both detectors are single-mode, the rate instead vanishes when the two projected modes coincide, regardless of the input modes. The paper further claims that the overlap integral between any two Laguerre-Gauss modes with different waist and propagation parameters is given in closed form by Eq. (34) through a Gauss hypergeometric function, and that this formula reproduces the numerically integrated values while running much faster.

Load-bearing premise

The whole derivation assumes the 50:50 beamsplitter transforms every spatial mode identically (only the orbital-angular-momentum index flips sign on reflection), so that reflectivity and transmissivity do not depend on the transverse spatial profile; if a real beamsplitter treats different spatial modes differently, the predicted coincidence rates would need correction.

Editorial extensions

If this is right

  • With bucket detectors, the HOM coincidence rate equals $\tfrac{1}{2}(1-|(\psi_1|\psi_2)|^2)$, so a measured HOM dip provides a direct, non-destructive measurement of the spatial fidelity between two photons.
  • With two single-mode detectors, the coincidence rate goes to zero when the two projected modes are identical regardless of the input states, and the rate encodes the relative phase structure between $\psi_1$ and $\psi_2$.
  • The general coincidence formula extends to correlated (entangled) two-photon inputs and to unbalanced beamsplitters via Eq. (27) and Eq. (28), covering realistic SPDC sources and imperfect devices.
  • The closed-form LG overlap (Eq. 34) allows exact evaluation of mode overlaps for any waist ratio and propagation mismatch, including regimes where LG modes lose orthogonality and exhibit crosstalk.
  • Because the formulas are both exact and fast to evaluate, they can be embedded in automated search loops that explore large spaces of linear optical experiments with structured photons.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If the beamsplitter's action is slightly mode-dependent, the general coincidence formula could be extended by replacing the scalar reflectivity and transmissivity with mode-dependent coefficients; a testable prediction is that HOM visibility for high-order LG modes would deviate from Eq. (23) in a systematic way.
  • The closed-form overlap for LG modes with different parameters may transfer directly to other linear-optics computations beyond HOM, such as mode sorter design, Gaussian optics propagation, or spatial-mode tomography, wherever LG overlaps with mismatched parameters occur.
  • The same antisymmetrized-overlap structure likely governs multi-photon interference beyond two photons, so the framework suggests a route to exact coincidence formulas for N-photon spatial-mode interference.
  • A practical extension would be to measure the inner product of two arbitrary spatial modes using the bucket-detector HOM rate, offering an overlap measurement that does not require phase-resolved holography.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 3 minor

Summary. The manuscript is a tutorial on Hong-Ou-Mandel interference for photons carrying structured transverse spatial modes. It derives a general coincidence-rate formula for two-photon product states under arbitrary spatial-mode projection (Eq. 21), specializes it to bucket, single-mode, and hybrid detection schemes (Eqs. 23–26), generalizes to correlated input states (Eqs. 27–28), and presents a closed-form overlap integral for Laguerre-Gauss modes with different waist and propagation parameters (Eq. 34). The final sections discuss applications to simulating quantum networks and to AI-driven discovery of quantum experiments.

Significance. If the derived formulas were correct, they would provide fast, closed-form predictions for spatial-mode HOM experiments and would support automated search over structured-photon experiments. The tutorial is clearly organized and the second-quantization approach is appropriate for the subject. However, the central coincidence-rate formula omits the OAM sign flip under reflection that the paper itself states in Eq. (9), and the closed-form LG overlap formula in Eq. (34) has a normalization error. Since the tutorial is specifically about structured photons carrying OAM, these are load-bearing defects rather than presentation issues. The paper therefore needs substantial correction before it can serve as a reliable reference.

major comments (3)
  1. [§3, Eqs. (9) and (15)–(21)] There is an internal inconsistency between the beamsplitter transformation stated in Eq. (9) and the one used in the main derivation. Eq. (9) says that reflection at the beamsplitter flips the OAM index: an input a†_{ℓ,p} produces output components c†_{−ℓ,p} and d†_{ℓ,p}. Eq. (15), however, uses the same label α on both output ports and no reflection operator, and Eq. (21) is derived from this simplified transformation. Repeating the derivation with the Eq. (9) transformation yields a different result, e.g. for ψ1=ψ2=|ℓ=+1⟩ and bucket detectors, Eq. (23) predicts R=0 while the reflection-aware calculation gives R=1/2. The discrepancy is not a small correction: for OAM-carrying inputs, the two predictions can be completely different. Because the tutorial’s stated focus is structured photons, this invalidates the claim that Eq. (21) and its specializations give exact coincidence rates under arbitrary spatial-mode projection.
  2. [§3.4, Eq. (27)] Eq. (27) contains a factor-of-2 normalization error relative to Eq. (21). For a product state ψ_{αβ}=ψ_{1,α}ψ_{2,β}, Eq. (27) evaluates to R=1−|⟨ψ1|ψ2⟩|², whereas the corresponding specialization of Eq. (21) gives R=(1/2)(1−|⟨ψ1|ψ2⟩|²). The factor-of-2 discrepancy is independent of the reflection issue and must be fixed for the correlated-state generalization to be consistent with the product-state limit.
  3. [§4, Eqs. (33)–(34)] The closed-form overlap formula Eq. (34) fails a basic consistency check. Setting ℓ=0, p=p′=0, w(z)=w′(z′), and z=z′ should yield the overlap of a mode with itself, namely 1. Using A from Eq. (33) and evaluating Eq. (34) for this case gives 1/(2π) instead. The prefactor A appears to be missing the factor 2π from the azimuthal integration and the factor (w(z)w′(z′))^{−|ℓ|} arising from the (√2ρ/w)^{|ℓ|} factors in Eq. (4). Since Eq. (34) is the main analytical contribution of Section 4, this error undermines the claimed speed-up and the numerical comparisons in Figs. 3(c) and 3(d).
minor comments (3)
  1. [§4, Eq. (30)] The notation LG_{ℓ,p}(μρ,φ;z) with μ=2/w(z)² is inconsistent with the argument structure of Eq. (4); the coefficient μ should multiply ρ² in the exponential and Laguerre arguments, not the radial coordinate itself.
  2. [Abstract/Keywords] The keyword list contains the typo “Laugerre Gauss Modes”; it should read “Laguerre-Gauss Modes.”
  3. [Fig. 1 caption] The caption introduces configurations A, B, and C that are not referenced or explained in the text; please clarify what each configuration represents.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the central HOM coincidence formula and the LG overlap integral are derived from stated operator transformations and direct integration, with no prediction reducing to its inputs by construction.

full rationale

The paper's derivation chain is self-contained. Section 3 starts from the input state expansion Eq. (14), applies the 50:50 beamsplitter transformation Eq. (15), and defines the coincidence projector Eq. (18); the central result Eq. (21) follows by direct operator algebra in Eq. (20). Nothing in this chain is fitted to the final coincidence rate, and the specializations in Eqs. (23), (24), and (26) are algebraic simplifications of Eq. (21) under stated detector assumptions. Section 4 derives the LG overlap formula Eq. (34) by substituting the explicit LG mode definition Eq. (4) into the integral Eq. (30), reducing the azimuthal part to a delta function and the radial part to a known hypergeometric integral with an independent literature citation [35]; the numerical comparisons in Fig. 3 additionally check the expression against quadrature. No parameter is fitted and then renamed a prediction, and no load-bearing assertion is justified solely by a self-citation. The authors do cite their own related work (e.g., Refs. [40] and [45]), but those citations are contextual, concerning Gouy-phase mode sorters and automated experiment discovery, and they do not supply the derivation of Eq. (21) or Eq. (34). The significant physical concern in the paper is the internal inconsistency between Eq. (9), which states that reflection at the beamsplitter flips the OAM index, and Eq. (15), which is used in the derivation without such a flip; this is a correctness or modeling issue, not a circularity issue, because the conclusion is not assumed through the input but rather follows from an incomplete model.

Assumptions & free parameters 0 free parameters · 4 assumptions · 0 invented entities

The central formulas rest on standard quantum optics assumptions about beamsplitter unitarity, LG basis completeness, and projective measurements. No free parameters are fitted to data.

assumptions (4)
  • domain assumption The beamsplitter acts as a lossless unitary transformation that is independent of the spatial mode, except for OAM sign flip.
    Used in Eq (15) to model the 50:50 BS as a† to (c†+d†)/√2 and b† to (c†-d†)/√2. Real beamsplitters may have mode-dependent reflectivity and transmissivity, and OAM modes reverse helicity on reflection (Eq 9).
  • domain assumption LG modes with fixed waist form a complete orthonormal basis.
    Invoked in Section 2 to expand arbitrary modes and to use orthogonality (ℓ,p|ℓ',p') = δ_ℓℓ' δ_pp'; this holds only for a fixed beam waist and propagation distance.
  • domain assumption Detectors are ideal projective measurements with pγ in {0,1}.
    Used in Eq (17) to model bucket, single-mode, and hybrid detectors; real detectors have finite efficiency and may have mode-dependent response.
  • domain assumption The two-photon input state is pure and frequency-degenerate, with one photon per port.
    Assumed in Eq (14) and Section 3.4; mixed states or frequency distinguishability would require additional degrees of freedom.

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Pith. "Pith review of Tutorial: Hong-Ou-Mandel interference with Structured Photons." pith.science (2026). https://pith.science/paper/EHOCMMOH

@misc{pith2026250114961,
  author       = {Pith},
  title        = {Pith review of: Tutorial: Hong-Ou-Mandel interference with Structured Photons},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/EHOCMMOH}},
  note         = {Machine review of arXiv:2501.14961}
}
read the original abstract

The Hong-Ou-Mandel (HOM) effect, an effective two-photon interference phenomenon, is a cornerstone of quantum optics and a key tool for linear optical quantum information processing. While the HOM effect has been extensively studied both theoretically and experimentally for various photonic quantum states, particularly in the spectral domain, detailed overviews of its behaviour for structured photons -- those with complex spatial profiles -- under arbitrary spatial mode measurement schemes are still lacking. This tutorial aims to fill this gap by providing a comprehensive theoretical analysis of the HOM effect for structured photons, including an arbitrary mode projection on quantum interference outcomes. The tutorial also provides analytical, closed-form expressions of the HOM visibility under different measurement conditions, which is a crucial contribution for its application in computational and artificial-intelligence-driven discovery of new quantum experiments exploiting the power of photons with complex spatial modes.

Figures

Figures reproduced from arXiv: 2501.14961 by the authors.

Figure 1
Figure 1. Examples of HOM experimental configurations. Photon pairs enter ports 𝑎 and 𝑏 of a beamsplitter, BS, and coincidences counts between the two output paths 𝑐 and 𝑑 are collected, typ￾ically after coupling to fibres (FC). Each detector can be either a single mode, represented by a single mode fibre (SMF), or a bucket/multimode detector, represented by a multimode fibre (MMF). 3 HOM visibility under different detection … view at source ↗
Figure 2
Figure 2. Illustration of HOM interference geometry for input pho￾tons having different mode parameters. We hereafter introduce 𝑤 ′ (𝑧 ′ ) and 𝑅′ (𝑧 ′ ) to indicate, respectively, the beam waist and the radius of curva￾ture of the beam at propagation distance 𝑧 ′ and having waist 𝑤 ′ 𝑜 and, consequently, Rayleigh range 𝑧 ′ 𝑜 . Thus, 𝜇 ′ is a coefficient that depends on 𝑤 ′ (𝑧 ′ ). In experi￾ments, if the distances and the cha… view at source ↗
Figure 3
Figure 3. Evaluation of |(𝑙, 𝑝|𝑙 ′𝑝 ′ )| 2 with 𝑙 = 𝑙 ′ = 2 and for different combinations of 𝑝, 𝑝′ ∈ [0, 6]. We demonstrate how the over￾lap between two beams changes (a) when the ratio of waists and (b) when the relative propagation distance between both beams changes. In both cases, the overlap between identical LG modes falls significantly, and we may observe “crosstalk" with other LG modes. We also report in (c) and (d) … view at source ↗
Figures from the paper (1 more)
Figure 4
Figure 4. Figure 4: Example experimental scenarios involving (a) two-photon interference with an incoming state |𝜓𝑖𝑛⟩ = |1𝑎⟩ |1𝑏⟩ and (b) multi-photon interference with |𝜓𝑖𝑛⟩ = |1𝑎⟩ |1𝑏⟩ |1𝑐⟩ |1𝑑⟩. The indices refer to different input ports to the BSs. The accumulated Gouy phase differenc…

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Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Tailoring spatial correlations with quantum interference

    quant-ph 2025-09 conditional novelty 5.0 of 10

    Two-photon correlations at a beam-splitter output can be spatially patterned and edited by tailoring the transverse polarization structure of the input photons.

Reference graph

Works this paper leans on

57 extracted references · 55 canonical work pages · cited by 1 Pith paper

  1. [1]

    Z.-Y. J. Ou, Multi-photon quantum interference , vol. 43. Springer, 2007

  2. [2]

    Measurement of subpicosecond time intervals between two photons by inter- ference,

    C.-K. Hong, Z.-Y. Ou, and L. Mandel, “Measurement of subpicosecond time intervals between two photons by inter- ference,” Physical review letters , vol. 59, no. 18, p. 2044, 1987

  3. [3]

    Fourth-order interference in parametric downconversion,

    J. G. Rarity and P. Tapster, “Fourth-order interference in parametric downconversion,”JOSA B, vol. 6, no. 6, pp. 1221–1226, 1989

  4. [4]

    Flu- orescence lifetime hong-ou-mandel sensing,

    A. Lyons, V. Zickus, R. Álvarez-Mendoza, D. Triggiani, V. Tamma, N. Westerberg, M. Tassieri, and D. Faccio, “Flu- orescence lifetime hong-ou-mandel sensing,”Nature Commu- nications, vol. 14, no. 1, p. 8005, 2023

  5. [5]

    Attosecond-resolution hong-ou- mandel interferometry,

    A. Lyons, G. C. Knee, E. Bolduc, T. Roger, J. Leach, E. M. Gauger, and D. Faccio, “Attosecond-resolution hong-ou- mandel interferometry,” Science advances, vol. 4, no. 5, p. eaap9416, 2018

  6. [6]

    Engineering two-photon high-dimensional states through quantum interference,

    Y. Zhang, F. S. Roux, T. Konrad, M. Agnew, J. Leach, and A. Forbes, “Engineering two-photon high-dimensional states through quantum interference,”Science advances, vol. 2, no. 2, p. e1501165, 2016

  7. [7]

    Manipulating the symmetry of transverse momentum entangled biphoton states,

    X. Gao, Y. Zhang, A. D’Errico, F. Hufnagel, K. Heshami, and E. Karimi, “Manipulating the symmetry of transverse momentum entangled biphoton states,”Optics Express, vol. 30, no. 12, pp. 21276–21281, 2022

  8. [8]

    Ex- perimental controlled-not logic gate for single photons in the coincidence basis,

    T. Pittman, M. Fitch, B. Jacobs, and J. Franson, “Ex- perimental controlled-not logic gate for single photons in the coincidence basis,”Physical Review A , vol. 68, no. 3, p. 032316, 2003

Show all 57 references
  1. [9]

    Realization of a photonic controlled-not gate sufficient for quantum computation,

    S. Gasparoni, J.-W. Pan, P. Walther, T. Rudolph, and A. Zeilinger, “Realization of a photonic controlled-not gate sufficient for quantum computation,”Physical Review Let- ters, vol. 93, no. 2, p. 020504, 2004

  2. [10]

    Two-photon interfer- ence: the hong–ou–mandel effect,

    F. Bouchard, A. Sit, Y. Zhang, R. Fickler, F. M. Miatto, Y. Yao, F. Sciarrino, and E. Karimi, “Two-photon interfer- ence: the hong–ou–mandel effect,”Reports on Progress in Physics, vol. 84, no. 1, p. 012402, 2020

  3. [11]

    High speed imaging of spectral-temporal correlations in hong-ou-mandel interference,

    Y. Zhang, D. England, A. Nomerotski, and B. Sussman, “High speed imaging of spectral-temporal correlations in hong-ou-mandel interference,” Optics Express, vol. 29, no. 18, pp. 28217–28227, 2021

  4. [12]

    Experimental entanglement concentration and universal bell-state synthesizer,

    Y.-H. Kim, S. P. Kulik, M. V. Chekhova, W. P. Grice, and Y. Shih, “Experimental entanglement concentration and universal bell-state synthesizer,” Physical Review A , vol. 67, no. 1, p. 010301, 2003

  5. [13]

    Opti- mal quantum cloning of orbital angular momentum photon qubits through hong–ou–mandel coalescence,

    E. Nagali, L. Sansoni, F. Sciarrino, F. De Martini, L. Mar- rucci, B. Piccirillo, E. Karimi, and E. Santamato, “Opti- mal quantum cloning of orbital angular momentum photon qubits through hong–ou–mandel coalescence,”Nature Pho- tonics, vol. 3, no. 12, pp. 720–723, 2009

  6. [14]

    Exploring the quantum nature of the radial degree of freedom of a photon via hong- ou-mandel interference,

    E. Karimi, D. Giovannini, E. Bolduc, N. Bent, F. M. Miatto, M. J. Padgett, and R. W. Boyd, “Exploring the quantum nature of the radial degree of freedom of a photon via hong- ou-mandel interference,” Physical Review A , vol. 89, no. 1, p. 013829, 2014

  7. [15]

    Generation of the complete bell basis via hong- ou-mandel interference,

    X. Gao, D. Paneru, F. Di Colandrea, Y. Zhang, and E. Karimi, “Generation of the complete bell basis via hong- ou-mandel interference,” arXiv preprint arXiv:2412.14274, 2024

  8. [16]

    Mandel, Optical Coherence and Quantum Optics

    L. Mandel, Optical Coherence and Quantum Optics . Cam- bridge University Press, 1995

  9. [17]

    M. O. Scully and M. S. Zubairy,Quantum optics. Cambridge university press, 1997

  10. [18]

    Garrison and R

    J. Garrison and R. Chiao,Quantum optics. OUP Oxford, 2008

  11. [19]

    A. E. Siegman,Lasers. University science books, 1986

  12. [20]

    Orbital angular momentum of light and the transfor- mation of laguerre-gaussian laser modes,

    L. Allen, M. W. Beijersbergen, R. Spreeuw, and J. Woerd- man, “Orbital angular momentum of light and the transfor- mation of laguerre-gaussian laser modes,”Physical review A , vol. 45, no. 11, p. 8185, 1992

  13. [21]

    Radial quantum number of laguerre-gauss modes,

    E. Karimi, R. Boyd, P. de la Hoz, H. de Guise, J. Rehacek, Z. Hradil, A. Aiello, G. Leuchs, and L. Sanchez-Soto, “Radial quantum number of laguerre-gauss modes,”Physical Review A, vol. 89, no. 6, 2014

  14. [22]

    Physical meaning of the radial index of laguerre-gauss beams,

    W. N. Plick and M. Krenn, “Physical meaning of the radial index of laguerre-gauss beams,”Physical Review A , vol. 92, no. 6, p. 063841, 2015

  15. [23]

    Linear optical quantum computing with photonic qubits,

    P. Kok, W. J. Munro, K. Nemoto, T. C. Ralph, J. P. Dowl- ing, and G. J. Milburn, “Linear optical quantum computing with photonic qubits,”Reviews of modern physics , vol. 79, no. 1, pp. 135–174, 2007

  16. [24]

    A quantum description of the beam splitter,

    S. Prasad, M. O. Scully, and W. Martienssen, “A quantum description of the beam splitter,”Optics communications, vol. 62, no. 3, pp. 139–145, 1987

  17. [25]

    Relation between input and output states for a beam splitter,

    Z. Ou, C. Hong, and L. Mandel, “Relation between input and output states for a beam splitter,”Optics communica- tions, vol. 63, no. 2, pp. 118–122, 1987

  18. [26]

    Quantum theory of the loss- less beam splitter,

    H. Fearn and R. Loudon, “Quantum theory of the loss- less beam splitter,” Optics communications, vol. 64, no. 6, pp. 485–490, 1987

  19. [27]

    Imaging spatiotemporal hong-ou-mandel interference of biphoton states of extremely high schmidt number,

    F. Devaux, A. Mosset, P.-A. Moreau, and E. Lantz, “Imaging spatiotemporal hong-ou-mandel interference of biphoton states of extremely high schmidt number,”Physical Review X, vol. 10, no. 3, p. 031031, 2020

  20. [28]

    High-speed imaging of spatiotemporal correlations in hong- ou-mandel interference,

    X. Gao, Y. Zhang, A. D’Errico, K. Heshami, and E. Karimi, “High-speed imaging of spatiotemporal correlations in hong- ou-mandel interference,” Optics Express, vol. 30, no. 11, pp. 19456–19464, 2022. Tareq Jaouni, Xuemei Gu, Mario Krenn, Alessio D’Errico, and Ebrahim Karimi, St...

  21. [29]

    Hologram of a single photon,

    R. Chrapkiewicz, M. Jachura, K. Banaszek, and W. Wasilewski, “Hologram of a single photon,”Nature Pho- tonics, vol. 10, no. 9, pp. 576–579, 2016

  22. [30]

    Intensity interferometry for holography with quantum and classical light,

    G. Thekkadath, D. England, F. Bouchard, Y. Zhang, M. Kim, and B. Sussman, “Intensity interferometry for holography with quantum and classical light,”Science Ad- vances, vol. 9, no. 27, p. eadh1439, 2023

  23. [31]

    Spatial correlations in parametric down-conversion,

    S. P. Walborn, C. Monken, S. Pádua, and P. S. Ribeiro, “Spatial correlations in parametric down-conversion,”Physics Reports, vol. 495, no. 4-5, pp. 87–139, 2010

  24. [32]

    Role of beam waist in laguerre–gauss expansion of vortex beams,

    G. Vallone, “Role of beam waist in laguerre–gauss expansion of vortex beams,”Optics letters, vol. 42, no. 6, pp. 1097– 1100, 2017

  25. [33]

    Yariv, P

    A. Yariv, P. Yeh, and A. Yariv,Photonics: optical electronics in modern communications , vol. 6. Oxford university press New York, 2007

  26. [34]

    B. E. Saleh and M. C. Teich,Fundamentals of photonics . john Wiley & sons, 2019

  27. [35]

    I. S. Gradshteyn and I. M. Ryzhik,Table of integrals, series, and products. Academic press, 2014

  28. [36]

    Scipy 1.0: fundamental algorithms for scientific computing in python,

    P. Virtanen, R. Gommers, T. E. Oliphant, M. Haber- land, T. Reddy, D. Cournapeau, E. Burovski, P. Peterson, W. Weckesser, J. Bright,et al., “Scipy 1.0: fundamental algorithms for scientific computing in python,”Nature meth- ods, vol. 17, no. 3, pp. 261–272, 2020

  29. [37]

    Accumulated gouy phase shift in gaussian beam propagation through first-order opti- cal systems,

    M. F. Erden and H. M. Ozaktas, “Accumulated gouy phase shift in gaussian beam propagation through first-order opti- cal systems,” JOSA A, vol. 14, no. 9, pp. 2190–2194, 1997

  30. [38]

    On the accumulated round-trip gouy phase shift for a general optical cavity,

    K. Arai, “On the accumulated round-trip gouy phase shift for a general optical cavity,”LIGO Technical Note, vol. 1300189, pp. 1–11, 2013

  31. [39]

    Sorting photons by radial quantum number,

    Y. Zhou, M. Mirhosseini, D. Fu, J. Zhao, S. M. Hashemi Rafsanjani, A. E. Willner, and R. W. Boyd, “Sorting photons by radial quantum number,”Physical review letters , vol. 119, no. 26, p. 263602, 2017

  32. [40]

    Gouy phase radial mode sorter for light: concepts and experiments,

    X. Gu, M. Krenn, M. Erhard, and A. Zeilinger, “Gouy phase radial mode sorter for light: concepts and experiments,” Physical review letters , vol. 120, no. 10, p. 103601, 2018

  33. [41]

    Computer-inspired quantum experiments,

    M. Krenn, M. Erhard, and A. Zeilinger, “Computer-inspired quantum experiments,” Nature Reviews Physics , vol. 2, no. 11, pp. 649–661, 2020

  34. [42]

    Artifi- cial intelligence and machine learning for quantum technolo- gies,

    M. Krenn, J. Landgraf, T. Foesel, and F. Marquardt, “Artifi- cial intelligence and machine learning for quantum technolo- gies,” Physical Review A , vol. 107, no. 1, p. 010101, 2023

  35. [43]

    Automated search for new quantum experi- ments,

    M. Krenn, M. Malik, R. Fickler, R. Lapkiewicz, and A. Zeilinger, “Automated search for new quantum experi- ments,” Physical review letters , vol. 116, no. 9, p. 090405, 2016

  36. [44]

    A search algorithm for quantum state engineer- ing and metrology,

    P. Knott, “A search algorithm for quantum state engineer- ing and metrology,”New Journal of Physics , vol. 18, no. 7, p. 073033, 2016

  37. [45]

    Digital discovery of 100 diverse quantum experiments with pytheus,

    C. Ruiz-Gonzalez, S. Arlt, J. Petermann, S. Sayyad, T. Jaouni, E. Karimi, N. Tischler, X. Gu, and M. Krenn, “Digital discovery of 100 diverse quantum experiments with pytheus,” Quantum, vol. 7, p. 1204, 2023

  38. [46]

    Digital discovery of interferometric gravitational wave detectors,

    M. Krenn, Y. Drori, and R. X. Adhikari, “Digital discovery of interferometric gravitational wave detectors,”arXiv preprint arXiv:2312.04258, 2023

  39. [47]

    How fast is a twisted photon?,

    A. Lyons, T. Roger, N. Westerberg, S. Vezzoli, C. Mait- land, J. Leach, M. J. Padgett, and D. Faccio, “How fast is a twisted photon?,” Optica, vol. 5, no. 6, pp. 682–686, 2018

  40. [48]

    Quantum optical metrology–the lowdown on high-n00n states,

    J. P. Dowling, “Quantum optical metrology–the lowdown on high-n00n states,”Contemporary physics, vol. 49, no. 2, pp. 125–143, 2008

  41. [49]

    Super- resolving phase measurements with a multiphoton entangled state,

    M. W. Mitchell, J. S. Lundeen, and A. M. Steinberg, “Super- resolving phase measurements with a multiphoton entangled state,” Nature, vol. 429, no. 6988, pp. 161–164, 2004

  42. [50]

    De broglie wavelength of a non-local four-photon state,

    P. Walther, J.-W. Pan, M. Aspelmeyer, R. Ursin, S. Gaspa- roni, and A. Zeilinger, “De broglie wavelength of a non-local four-photon state,” Nature, vol. 429, no. 6988, pp. 158–161, 2004

  43. [51]

    Beating the standard quantum limit with four- entangled photons,

    T. Nagata, R. Okamoto, J. L. O’brien, K. Sasaki, and S. Takeuchi, “Beating the standard quantum limit with four- entangled photons,” Science, vol. 316, no. 5825, pp. 726– 729, 2007

  44. [52]

    High-noon states by mixing quantum and classical light,

    I. Afek, O. Ambar, and Y. Silberberg, “High-noon states by mixing quantum and classical light,”Science, vol. 328, no. 5980, pp. 879–881, 2010

  45. [53]

    Uncon- ditional violation of the shot-noise limit in photonic quantum metrology,

    S. Slussarenko, M. M. Weston, H. M. Chrzanowski, L. K. Shalm, V. B. Verma, S. W. Nam, and G. J. Pryde, “Uncon- ditional violation of the shot-noise limit in photonic quantum metrology,” Nature Photonics, vol. 11, no. 11, pp. 700–703, 2017

  46. [54]

    Sub-shot-noise interferometric measurements with two-photon states,

    A. Kuzmich and L. Mandel, “Sub-shot-noise interferometric measurements with two-photon states,”Quantum and Semi- classical Optics: Journal of the European Optical Society Part B, vol. 10, no. 3, p. 493, 1998

  47. [55]

    Observation of the quantum gouy phase,

    M. Hiekkamäki, R. F. Barros, M. Ornigotti, and R. Fickler, “Observation of the quantum gouy phase,”Nature Photon- ics, vol. 16, no. 12, pp. 828–833, 2022

  48. [56]

    High-dimensional two- photon interference effects in spatial modes,

    M. Hiekkamäki and R. Fickler, “High-dimensional two- photon interference effects in spatial modes,”Physical Re- view Letters, vol. 126, no. 12, p. 123601, 2021

  49. [57]

    Photonic polarization gears for ultra-sensitive angular measurements,

    V. D’ambrosio, N. Spagnolo, L. Del Re, S. Slussarenko, Y. Li, L. C. Kwek, L. Marrucci, S. P. Walborn, L. Aolita, and F. Sciarrino, “Photonic polarization gears for ultra-sensitive angular measurements,” Nature communications, vol. 4, no. 1, p. 2432, 2013

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