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Figure 4.43: Proposed JSA scanning setup Figure 4.44: Predicted JSA measurement 62
This is the silliest stuff that ever I heard. William Shakespeare A Midsummer Night’s dream 5 Conclusion and Outlook In the past year considerable progress has been made towards a pure heralded single photon source. We were able to extend the analysis of wave propagation inside a waveguide to spatial modal effects in collaboration with Thomas Lauckner and Division 3. Effects that have just recently been observed in experiments by Kaisa Laiho. We analyzed different possibilities to produce pure heralded single photon states inside a waveguide ranging from the first attempts with spectral filtering to crystal engineering, where uncorrelated photon pairs are produced directly in the downconversion process. The first setups employing this method are currently under development in the laboratory. We pushed this approach even further by investigating the possibility of generating uncorrelated counterpropagating photon pairs inside a waveguide geometry. The inherent decorrelation and separation of photon pairs inside the crystal may be a further step to the integration and miniaturization of these single photon sources. Several groups are currently facing the challenge of producing chips with a submicrometer grating period. Our characterization of the id201 APDs provided knowledge of their noise properties. The gained data will prove useful for future work with these single photon detectors. SHG proved to be a valuable tool to investigate the phasematching properties of our crystal samples. We were able to identify all degenerate phasematching points and to compare our modelling with actual data. There are still discrepancies between theory and experiment, but only moderate fitting is necessary to reach a good agreement. Despite all simplifications in the derivation of the two-photon-state, we showed that our theoretical treatment is sufficient. Further improvement could be made by a more precise model of the waveguiding structures. Finally we used the SHG data to find a PDC process degenerate in frequency. First results are very promising. We are looking forward to see a bright pure heralded single photon source in the near future. 63
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Towards a pure heralded single phot
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ii A.2 id201 programming . . . . .
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Chapter 1. Overview 2
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experimental data. This thesis is d
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a nonlinear, nonmagnetic material,
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Figure 3.3: Parametric down convers
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For the volume integration, we rest
Page 16 and 17: Figure 3.5: 1D square-wave periodic
Page 18 and 19: and 3.10). Figure 3.9: 0-0 waveguid
Page 20 and 21: By inserting the corresponding term
Page 22 and 23: Λi phasematching Λs Figure 3.18:
Page 24 and 25: pump mode → signal mode + idler m
Page 26 and 27: Hence, we have to ensure a separabl
Page 28 and 29: 3.2.2 Frequency entanglement of two
Page 30 and 31: 3.3 Generating pure heralded single
Page 32 and 33: Material: KTP Polarizations: y →
Page 34 and 35: Material: KTP Polarizations: y →
Page 36 and 37: 32 Ωi�PHz� 1.26 1.23 1.2 Φ
Page 38 and 39: The first appealing feature of coun
Page 40 and 41: Ωi�PHz� 0.10 0.05 1.22 1.215
Page 42 and 43: 38 Figure 3.53: Different pump freq
Page 45 and 46: 4 Experiment 4.1 Avalanche photodio
Page 47 and 48: kcounts / second 0.14 0.12 0.1 0.08
Page 49 and 50: kcounts per second 180 160 140 120
Page 51 and 52: or z-polarization, and we are left
Page 53 and 54: Gaussian functions. The result is a
Page 55 and 56: that the phasematching point was sh
Page 57 and 58: this two dimension plane on the bla
Page 59 and 60: plotted in Appendix A.4.3. Shg powe
Page 61 and 62: kSHG(762.5nm) 14.5506/ µm kp1(1525
Page 63 and 64: kSHG(762.5nm) 14.2703/ µm kp1(1525
Page 65: Outlook measurement signal counts/s
Page 70 and 71: �� pdc package Ver: 1.0 Main pa
Page 72 and 73: �� this is a list of all variab
Page 74 and 75: ��refracrtive index of the o�
Page 76 and 77: ��Begin: Sellmeier Equations fo
Page 78 and 79: optnp�getOpt�np,opts,defaults
Page 80 and 81: ��joint spectral amplitude with
Page 82 and 83: findRootdk2�opts��:�f
Page 84 and 85: ��self written assert package
Page 86 and 87: 2 myUnits.m �� 10^�11 ��
Page 88 and 89: 2 enhancedSellmeier.m ��Print
Page 90 and 91: 4 enhancedSellmeier.m iassert�opt
Page 92 and 93: 6 enhancedSellmeier.m ��extract
Page 94 and 95: 8 enhancedSellmeier.m opte � ToEx
Page 96 and 97: 10 enhancedSellmeier.m ��refrac
Page 98 and 99: 12 enhancedSellmeier.m iassert�op
Page 100 and 101: 14 enhancedSellmeier.m If�optairB
Page 102 and 103: 2 wmschmidt.m compact carrier �0,
Page 104 and 105: A.2 id201 programming The data acqu
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Page 108 and 109: (EXIM LSQI EGLVMWX 0EFSV MH MH ûMH
Page 110 and 111: (EXIM LSQI EGLVMWX 0EFSV MH MH ûMH
Page 112 and 113: (EXIM LSQI EGLVMWX 0EFSV MH MH û T
Page 114 and 115: kcounts / second kcounts / second k
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kcounts / second 80 70 60 50 40 30
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kcounts per second kcounts per seco
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E y E y -> E y E y E y -> E z E y E
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BCT0703-B12 second measurement The
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Shg power Pump power [a.u.] Shg pow
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Shg power Pump power [a.u.] 90 80 7
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ITI0706-B124 power measurement The
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Bibliography [1] H. J. Kimble, M. D
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[25] Carlot Canalias and Valdas Pas
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Thanks ❏ To Dr. Christine Silberh
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Erklärung Gemäß §31(2) der Dipl
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