@article{EichlerHaaseMenzeletal.1994,
  author    = {Eichler, Hans Joachim and Haase, Alfred and Menzel, Ralf and Schwartz, J.},
  title     = {Depolarization treatment and optimization of high power double pass neodym-rod amplifiers with SBS mirror},
  year      = {1994},
  language  = {en}
}
@article{KlemzKubinaOstermeyeretal.2001,
  author    = {Klemz, Guido and Kubina, P. and Ostermeyer, Martin and Menzel, Ralf},
  title     = {Diode pumped high power TEM_00 Nd:YAG rod laser with birefringence compensation},
  year      = {2001},
  language  = {en}
}
@article{OstermeyerKappeMenzeletal.2005,
  author    = {Ostermeyer, Martin and Kappe, Philip and Menzel, Ralf and Wulfmeyer, Volker},
  title     = {Diode-pumped Nd : YAG master oscillator power amplifier with high pulse energy, excellent beam quality, and frequency-stabilized master oscillator as a basis for a next-generation lidar system},
  issn      = {0003-6935},
  year      = {2005},
  abstract  = {In the original publication [Ostermeyer et al., Appl. Opt., 44, 582-590 (2005)], Fig. 5 appeared twice as Figs. 4 and 5. This inaccuracy is corrected here. (c) 2005 Optical Society of America},
  language  = {en}
}
@book{OstermeyerKappeMenzeletal.2005,
  author    = {Ostermeyer, Martin and Kappe, Philip and Menzel, Ralf and Wulfmeyer, Volker},
  title     = {Diode-pumped Nd : YAG master oscillator power amplifier with high pulse energy, excellent beam quality, and frequency-stabilized master oscillator as a basis for a next-generation lidar system},
  year      = {2005},
  abstract  = {A pulsed, diode-laser-pumped Nd:YAG master oscillator power amplifier (MOPA) in rod geometry, frequency stabilized with a modified Pound-Drever-Hall scheme is presented. The apparatus delivers 33-ns pulses with a maximum pulse energy of 0.5 J at 1064 nm. The system was set up in two different configurations for repetition rates of 100 or 250 Hz. The beam quality was measured to be 1.5 times the diffraction limit at a pulse energy of 405 mJ and a repetition rate of 100 Hz. At 250 Hz with the same pulse energy, the M-2 was better than 2.1. The radiation is frequency converted with an efficiency of 50\% to 532 nm. This MOPA system will be the pump laser of transmitters for a variety of high-end, scanning lidar systems. (C) 2005 Optical Society of America},
  language  = {en}
}
@article{OstermeyerKlemzMenzel2002,
  author    = {Ostermeyer, Martin and Klemz, Guido and Menzel, Ralf},
  title     = {Double rod Nd:YAG laser with 180 W average output and diffraction limited beam quality via path-matched birefringence compensation},
  isbn      = {0-8194-4368-9},
  year      = {2002},
  language  = {en}
}
@article{RaetzelWilkensMenzel2017,
  author    = {R{\"a}tzel, Dennis and Wilkens, Martin and Menzel, Ralf},
  title     = {Effect of polarization entanglement in photon-photon scattering},
  series = {Physical review : A, Atomic, molecular, and optical physics},
  volume    = {95},
  journal   = {Physical review : A, Atomic, molecular, and optical physics},
  number    = {1},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {2469-9926},
  doi       = {10.1103/PhysRevA.95.012101},
  pages     = {6},
  year      = {2017},
  abstract  = {It is found that the differential cross section of photon-photon scattering is a function of the degree of polarization entanglement of the two-photon state. A reduced general expression for the differential cross section of photon-photon scattering is derived by applying simple symmetry arguments. An explicit expression is obtained for the example of photon-photon scattering due to virtual electron-positron pairs in quantum electrodynamics. It is shown how the effect in this explicit example can be explained as an effect of quantum interference and that it fits with the idea of distance-dependent forces.},
  language  = {en}
}
@article{MenzelRaabLorenzetal.2000,
  author    = {Menzel, Ralf and Raab, Volker and Lorenz, Dieter and Heuer, Axel},
  title     = {Efficient phase conjugating mirror with a low threshold in a tapered optical fiber},
  year      = {2000},
  language  = {en}
}
@article{SkoczowskyJechowMenzeletal.2010,
  author    = {Skoczowsky, Danilo and Jechow, Andreas and Menzel, Ralf and Paschke, Katrin and Erbert, G{\"o}tz},
  title     = {Efficient second-harmonic generation using a semiconductor tapered amplifier in a coupled ring-resonator geometry},
  issn      = {0146-9592},
  doi       = {10.1364/OL.35.000232},
  year      = {2010},
  abstract  = {A new approach for efficient second-harmonic generation using diode lasers is presented. The experimental setup is based on a tapered amplifier operated in a ring resonator that is coupled to a miniaturized enhancement ring resonator containing a periodically poled lithium niobate crystal. Frequency locking of the diode laser emission to the resonance frequency of the enhancement cavity is realized purely optically, resulting in stable, single-frequency operation. Blue light at 488 nm with an output power of 310 mW is generated with an optical-to-optical conversion efficiency of 18\%.},
  language  = {en}
}
@article{HeuerHodgsonMenzel1998,
  author    = {Heuer, Axel and Hodgson, N. and Menzel, Ralf},
  title     = {Efficient, low-threshold phase conjugation in a tapered optical fiber},
  year      = {1998},
  language  = {en}
}
@article{TedeschiLiMoehwaldetal.2004,
  author    = {Tedeschi, Concetta and Li, L. and M{\"o}hwald, Helmuth and Spitz, Christian and von Seggern, David and Menzel, Ralf and Kirstein, Stefan},
  title     = {Engineering of layer-by-layer coated capsules with the prospect of materials for efficient and directed electron transfer},
  year      = {2004},
  abstract  = {We show a Lefschetz fixed point formula for holomorphic functions in a bounded domain D with smooth boundary in the complex plane. To introduce the Lefschetz number for a holomorphic map of D, we make use of the Bergman kernel of this domain. The Lefschetz number is proved to be the sum of the usual contributions of fixed points of the map in D and contributions of boundary fixed points, these latter being different for attracting and repulsing fixed points},
  language  = {en}
}
@article{OstermeyerKlemzKubinaetal.2005,
  author    = {Ostermeyer, Martin and Klemz, Guido and Kubina, P. and Menzel, Ralf},
  title     = {Enhanced brightness and extraction efficiency of Nd:YAG rod lasers resulting in 180 W output power with M2<1.2},
  isbn      = {1-557-52697-4},
  year      = {2005},
  language  = {en}
}
@article{LorenzMittlerBrandenburgetal.2000,
  author    = {Lorenz, Dieter and Mittler, Kay and Brandenburg, Ingo and Menzel, Ralf},
  title     = {Enhanced coherence radar measurements with spectrally broadened Ti:sapphire laser using nonlinear absorber},
  isbn      = {08194-3546-5},
  year      = {2000},
  abstract  = {D. Lorenz, K. Mittler, I. Brandenburg, R. Menze},
  language  = {en}
}
@article{JechowSeefeldtKurzkeetal.2013,
  author    = {Jechow, Andreas and Seefeldt, Michael and Kurzke, Henning and Heuer, Axel and Menzel, Ralf},
  title     = {Enhanced two-photon excited fluorescence from imaging agents using true thermal light},
  series = {Nature photonics},
  volume    = {7},
  journal   = {Nature photonics},
  number    = {12},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {1749-4885},
  doi       = {10.1038/NPHOTON.2013.271},
  pages     = {973 -- 976},
  year      = {2013},
  abstract  = {Two-photon excited fluorescence (TPEF) is a standard technique in modern microscopy(1), but is still affected by photodamage to the probe. It has been proposed that TPEF can be enhanced using entangled photons(2,3), but this has proven challenging. Recently, it was shown that some features of entangled photons can be mimicked with thermal light, which finds application in ghost imaging(4), subwavelength lithography(5) and metrology(6). Here, we use true thermal light from a superluminescent diode to demonstrate TPEF that is enhanced compared to coherent light, using two common fluorophores and luminescent quantum dots, which suit applications in imaging and microscopy. We find that the TPEF rate is directly proportional to the measured(7) degree of second-order coherence, as predicted by theory. Our results show that photon bunching in thermal light can be exploited in two-photon microscopy, with the photon statistic providing a new degree of freedom.},
  language  = {en}
}
@misc{MenzelHeuerMilonni2019,
  author    = {Menzel, Ralf and Heuer, Axel and Milonni, Peter W.},
  title     = {Entanglement, complementarity, and vacuum fields in spontaneous parametric down-conversion},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1077},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-47354},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-473542},
  pages     = {16},
  year      = {2019},
  abstract  = {Using two crystals for spontaneous parametric down-conversion in a parallel setup, we observe two-photon interference with high visibility. The high visibility is consistent with complementarity and the absence of which-path information. The observations are explained as the effects of entanglement or equivalently in terms of interfering probability amplitudes and also by the calculation of a second-order field correlation function in the Heisenberg picture. The latter approach brings out explicitly the role of the vacuum fields in the down-conversion at the crystals and in the photon coincidence counting. For comparison, we show that the Hong-Ou-Mandel dip can be explained by the same approach in which the role of the vacuum signal and idler fields, as opposed to entanglement involving vacuum states, is emphasized. We discuss the fundamental limitations of a theory in which these vacuum fields are treated as classical, stochastic fields.},
  language  = {en}
}
@article{MenzelHeuerMilonni2019,
  author    = {Menzel, Ralf and Heuer, Axel and Milonni, Peter W.},
  title     = {Entanglement, Complementarity, and Vacuum Fields in Spontaneous Parametric Down-Conversion},
  series = {Atoms},
  volume    = {7},
  journal   = {Atoms},
  number    = {1},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2218-2004},
  doi       = {10.3390/atoms7010027},
  pages     = {14},
  year      = {2019},
  abstract  = {Using two crystals for spontaneous parametric down-conversion in a parallel setup, we observe two-photon interference with high visibility. The high visibility is consistent with complementarity and the absence of which-path information. The observations are explained as the effects of entanglement or equivalently in terms of interfering probability amplitudes and also by the calculation of a second-order field correlation function in the Heisenberg picture. The latter approach brings out explicitly the role of the vacuum fields in the down-conversion at the crystals and in the photon coincidence counting. For comparison, we show that the Hong-Ou-Mandel dip can be explained by the same approach in which the role of the vacuum signal and idler fields, as opposed to entanglement involving vacuum states, is emphasized. We discuss the fundamental limitations of a theory in which these vacuum fields are treated as classical, stochastic fields.},
  language  = {en}
}
@article{EichlerMacdonaldMenzeletal.1995,
  author    = {Eichler, Hans Joachim and Macdonald, R. and Menzel, Ralf and Sander, Rolf},
  title     = {Excited state absorption of 5CB (4'-n-pentyl-4-cyanobiphenyl) in cyclohexane},
  year      = {1995},
  language  = {en}
}
@article{RaabMenzel2002,
  author    = {Raab, Volker and Menzel, Ralf},
  title     = {External resonator design for high-power laser diodes that yields 400 mW of TEM00 power},
  year      = {2002},
  language  = {en}
}
@article{MenzelOstermeyer1998,
  author    = {Menzel, Ralf and Ostermeyer, Martin},
  title     = {Fundamental mode determination for guaranteeing diffrraction limited beam quality of lasers with high output powers},
  year      = {1998},
  language  = {en}
}
@misc{RaetzelWilkensMenzel2016,
  author    = {R{\"a}tzel, Dennis and Wilkens, Martin and Menzel, Ralf},
  title     = {Gravitational properties of light},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90553},
  year      = {2016},
  abstract  = {The gravitational field of a laser pulse of finite lifetime, is investigated in the framework of linearized gravity. Although the effects are very small, they may be of fundamental physical interest. It is shown that the gravitational field of a linearly polarized light pulse is modulated as the norm of the corresponding electric field strength, while no modulations arise for circular polarization. In general, the gravitational field is independent of the polarization direction. It is shown that all physical effects are confined to spherical shells expanding with the speed of light, and that these shells are imprints of the spacetime events representing emission and absorption of the pulse. Nearby test particles at rest are attracted towards the pulse trajectory by the gravitational field due to the emission of the pulse, and they are repelled from the pulse trajectory by the gravitational field due to its absorption. Examples are given for the size of the attractive effect. It is recovered that massless test particles do not experience any physical effect if they are co-propagating with the pulse, and that the acceleration of massless test particles counter-propagating with respect to the pulse is four times stronger than for massive particles at rest. The similarities between the gravitational effect of a laser pulse and Newtonian gravity in two dimensions are pointed out. The spacetime curvature close to the pulse is compared to that induced by gravitational waves from astronomical sources.},
  language  = {en}
}
@article{RaetzelWilkensMenzel2016,
  author    = {R{\"a}tzel, Dennis and Wilkens, Martin and Menzel, Ralf},
  title     = {Gravitational properties of light},
  series = {New journal of physics : the open-access journal for physics},
  volume    = {18},
  journal   = {New journal of physics : the open-access journal for physics},
  publisher = {IOP Science},
  address   = {London},
  issn      = {1367-2630},
  doi       = {10.1088/1367-2630/18/2/023009},
  pages     = {1 -- 16},
  year      = {2016},
  abstract  = {The gravitational field of a laser pulse of finite lifetime, is investigated in the framework of linearized gravity. Although the effects are very small, they may be of fundamental physical interest. It is shown that the gravitational field of a linearly polarized light pulse is modulated as the norm of the corresponding electric field strength, while no modulations arise for circular polarization. In general, the gravitational field is independent of the polarization direction. It is shown that all physical effects are confined to spherical shells expanding with the speed of light, and that these shells are imprints of the spacetime events representing emission and absorption of the pulse. Nearby test particles at rest are attracted towards the pulse trajectory by the gravitational field due to the emission of the pulse, and they are repelled from the pulse trajectory by the gravitational field due to its absorption. Examples are given for the size of the attractive effect. It is recovered that massless test particles do not experience any physical effect if they are co-propagating with the pulse, and that the acceleration of massless test particles counter-propagating with respect to the pulse is four times stronger than for massive particles at rest. The similarities between the gravitational effect of a laser pulse and Newtonian gravity in two dimensions are pointed out. The spacetime curvature close to the pulse is compared to that induced by gravitational waves from astronomical sources.},
  language  = {en}
}