TY - JOUR A1 - Menzel, Ralf A1 - Puhlmann, Dirk A1 - Heuer, Axel A1 - Schleich, Wolfgang P. T1 - Wave-particle dualism and complementarity unraveled by a different mode JF - Proceedings of the National Academy of Sciences of the United States of America N2 - The precise knowledge of one of two complementary experimental outcomes prevents us from obtaining complete information about the other one. This formulation of Niels Bohr's principle of complementarity when applied to the paradigm of wave-particle dualism-that is, to Young's double-slit experiment-implies that the information about the slit through which a quantum particle has passed erases interference. In the present paper we report a double-slit experiment using two photons created by spontaneous parametric down-conversion where we observe interference in the signal photon despite the fact that we have located it in one of the slits due to its entanglement with the idler photon. This surprising aspect of complementarity comes to light by our special choice of the TEM01 pump mode. According to quantum field theory the signal photon is then in a coherent superposition of two distinct wave vectors giving rise to interference fringes analogous to two mechanical slits. Y1 - 2012 U6 - https://doi.org/10.1073/pnas.1201271109 SN - 0027-8424 VL - 109 IS - 24 SP - 9314 EP - 9319 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Schwarze, Thomas A1 - Garz, Andreas A1 - Teuchner, Klaus A1 - Menzel, Ralf A1 - Holdt, Hans-Jürgen T1 - Two-photon probes for metal ions based on phenylaza[18]crown-6 ethers and 1,2,3-triazoles as pi-linkers JF - ChemPhysChem : a European journal of chemical physics and physical chemistry KW - absorption KW - cations KW - click chemistry KW - dyes/pigments KW - fluorescence Y1 - 2014 U6 - https://doi.org/10.1002/cphc.201402232 SN - 1439-4235 SN - 1439-7641 VL - 15 IS - 12 SP - 2436 EP - 2439 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Elsner, Robert A1 - Ullmann, Roland A1 - Heuer, Axel A1 - Menzel, Ralf A1 - Ostermeyer, Martin T1 - Two-dimensional modeling of transient gain gratings in saturable gain media JF - OPTICS EXPRESS N2 - A transient two-dimensional model describing degenerate four-wave mixing inside saturable gain media is presented. The new model is compared to existing one-dimensional models with their qualitative results confirmed. Large quantitative differences with respect to peak reflectivity and optimum pump fluence are observed. Furthermore, the influence of the beam focus size, the transverse position and the crossing angle on the reflectivity of the grating is investigated using the improved model. It is demonstrated that the phase conjugate reflectivity depends sensitively on the transverse features of the interacting beams with a transverse shift in the position of the pump beams yielding a threefold improvement in reflectivity. (C) 2012 Optical Society of America Y1 - 2012 U6 - https://doi.org/10.1364/OE.20.006887 SN - 1094-4087 VL - 20 IS - 7 SP - 6887 EP - 6896 PB - OPTICAL SOC AMER CY - WASHINGTON ER - TY - JOUR A1 - Raab, Volker A1 - Skoczowsky, Danilo A1 - Menzel, Ralf T1 - Tuning high-power diodes with as much as 0.38 W of power and M2 = 1.2 over a range of 32 nm with 3-GHz bandwidth Y1 - 2003 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Lorenz, Dieter A1 - Hodgson, N. A1 - Menzel, Ralf T1 - Transverse Modes in Laser Resonators with Phase Conjugating Mirror Based on Stimulated Brillouin Scattering (SBS) Y1 - 1997 ER - TY - JOUR A1 - Heuer, Axel A1 - Schultheiss, J. A1 - Hodgson, N. A1 - Kurths, Jürgen A1 - Menzel, Ralf A1 - Raab, Volker T1 - Transverse effects in phase conjugate laser mirrors based on stimulated brillouin scattering Y1 - 1999 ER - TY - JOUR A1 - Elsner, Robert A1 - Puhlmann, Dirk A1 - Pieplow, Gregor A1 - Heuer, Axel A1 - Menzel, Ralf T1 - Transverse distinguishability of entangled photons with arbitrarily shaped spatial near- and far-field distributions JF - Journal of the Optical Society of America : B, Optical physics N2 - Entangled photons generated by spontaneous parametric downconversion are ubiquitous in quantum optics. In general, they exhibit a complex spatial photon count distribution. This spatial structure is responsible for seemingly surprising results concerning, e.g., complementarity such as the apparent simultaneous observation of interference fringes V and which-way information D at a double slit, as recently reported by Menzel et al. [Proc. Natl. Acad. Sci. USA 109, 9314 (2012)]. We implement a complete quantitative model of the SPDC interaction that fully incorporates the effects of crystal anisotropies, phase matching, and the pump beam structure and allows for arbitrary manipulations of the SPDC light in the near and far fields. This enables us to establish an upper bound D-2 + V-2 <= 1.47 for the experimental parameters reported by Menzel et al. We report new experimental results that agree excellently with these theoretical predictions. The new model enables a detailed quantitative analysis of this surprising result and the fair sampling interpretation of biphotons passing a double slit. (C) 2015 Optical Society of America Y1 - 2015 U6 - https://doi.org/10.1364/JOSAB.32.001910 SN - 0740-3224 SN - 1520-8540 VL - 32 IS - 9 SP - 1910 EP - 1919 PB - Optical Society of America CY - Washington ER - TY - JOUR A1 - Sander, Rolf A1 - Herrmann, V. A1 - Menzel, Ralf T1 - Transient absorption spectra and bleaching of 4'-n-Pentyl-4-Cyanoterphenyl in Cyclohexane : determination of cross sections and recovery times Y1 - 1996 ER - TY - JOUR A1 - Mittler, Kay A1 - Lorenz, Dieter A1 - Menzel, Ralf T1 - Time-resolved measurements of the spectra of a broadband laser used as light source for the coherence radar Y1 - 1999 ER - TY - JOUR A1 - Mittler, Kay A1 - Lorenz, Dieter A1 - Menzel, Ralf T1 - Time resolved emission spectra of a broadband ns-laser with 0.5 W average output power used as light source for the coherence radar Y1 - 1999 ER - TY - JOUR A1 - Hänisch, Christoph A1 - Heuer, Axel A1 - Menzel, Ralf T1 - Threshold reduction of stimulated Brillouin scattering (SBS) using fiber loop schemes Y1 - 2001 ER - TY - JOUR A1 - Menzel, Ralf A1 - Marx, Robert A1 - Puhlmann, Dirk A1 - Heuer, Axel A1 - Schleich, Wolfgang T1 - The photon BT - the role of its mode function in analyzing complementarity JF - Journal of the Optical Society of America : B, Optical physics N2 - We investigate the role of the spatial mode function in a single-photon experiment designed to demonstrate the principle of complementarity. Our approach employs entangled photons created by spontaneous parametric downconversion from a pump mode in a TEM01 mode together with a double slit. Measuring the interference of the signal photons behind the double slit in coincidence with the entangled idler photons at different positions, we select signal photons of different mode functions. When the signal photons belong to the TEM01-like double-hump mode, we obtain almost perfect visibility of the interference fringes, and no "which slit" information is available in the idler photon detected before the slits. This result is remarkable because the entangled signal and idler photon pairs are created each time in only one of the two intensity humps. However, when we break the symmetry between the two maxima of the signal photon mode structure, the paths through the slits for these additional photons become distinguishable and the visibility vanishes. It is the mode function of the photons selected by the detection system that decides if interference or "which slit" information is accessible in the experiment. Y1 - 2019 U6 - https://doi.org/10.1364/JOSAB.36.001668 SN - 0740-3224 SN - 1520-8540 VL - 36 IS - 6 SP - 1668 EP - 1675 PB - Optical Society of America CY - Washington ER - TY - JOUR A1 - Rätzel, Dennis A1 - Wilkens, Martin A1 - Menzel, Ralf T1 - The effect of entanglement in gravitational photon-photon scattering JF - epl : a letters journal exploring the frontiers of physics N2 - The differential cross-section for gravitational photon-photon scattering calculated in perturbative quantum gravity is shown to depend on the degree of polarization entanglement of the two photons. The interaction between photons in the symmetric Bell state is stronger than between not entangled photons. In contrast, the interaction between photons in the anti-symmetric Bell state is weaker than between not entangled photons. The results are interpreted in terms of quantum interference, and it is shown how they fit into the idea of distance-dependent forces. Copyright (C) EPLA, 2016 Y1 - 2016 U6 - https://doi.org/10.1209/0295-5075/115/51002 SN - 0295-5075 SN - 1286-4854 VL - 115 SP - S12 EP - S13 PB - EDP Sciences CY - Mulhouse ER - TY - JOUR A1 - Afshaarvahid, Shahraam A1 - Heuer, Axel A1 - Menzel, Ralf A1 - Munch, Jesper T1 - Temporal structure of stimulated-Brillouin-scattering reflectivity considering transversal-mode development Y1 - 2001 ER - TY - JOUR A1 - Heuer, Axel A1 - Menzel, Ralf T1 - Temporal features of SBS phase conjugation Y1 - 2000 SN - 0-8194-3545-7 ER - TY - JOUR A1 - Jechow, Andreas A1 - Lichtner, Mark A1 - Menzel, Ralf A1 - Radziunas, Mindaugas A1 - Skoczowsky, Danilo A1 - Vladimirov, Andrei G. T1 - Stripe-array diode-laser in an off-axis external cavity : theory and experiment N2 - Stripe-array diode lasers naturally operate in an anti-phase supermode. This produces a sharp double lobe far field at angles ña depending on the period of the array. In this paper a 40 emitter gain guided stripe-array laterally coupled by off-axis filtered feedback is investigated experimentally and numerically. We predict theoretically and confirm experimentally that at doubled feedback angle 2a a stable higher order supermode exists with twice the number of emitters per array period. The theoretical model is based on time domain traveling wave equations for optical fields coupled to the carrier density equation taking into account diffusion of carriers. Feedback from the external reflector is modeled using Fresnel integration. Y1 - 2009 UR - http://www.opticsinfobase.org/oe/Issue.cfm U6 - https://doi.org/10.1364/OE.17.019599 SN - 1094-4087 ER - TY - JOUR A1 - Jechow, Andreas A1 - Lichtner, Mark A1 - Menzel, Ralf A1 - Radziunas, Mindaugas A1 - Skoczowsky, Danilo A1 - Vladimirov, Andrei G. T1 - Stripe-array diode-laser in an off-axis external cavity : theory and experiment N2 - Stripe-array diode lasers naturally operate in an anti-phase supermode. This produces a sharp double lobe far field at angles +/-alpha depending on the period of the array. In this paper a 40 emitter gain guided stripe-array laterally coupled by off-axis filtered feedback is investigated experimentally and numerically. We predict theoretically and confirm experimentally that at doubled feedback angle 2 alpha a stable higher order supermode exists with twice the number of emitters per array period. The theoretical model is based on time domain traveling wave equations for optical fields coupled to the carrier density equation taking into account diffusion of carriers. Feedback from the external reflector is modeled using Fresnel integration. Y1 - 2009 UR - http://www.opticsexpress.org/Issue.cfm U6 - https://doi.org/10.1364/OE.17.019599 SN - 1094-4087 ER - TY - JOUR A1 - Lorenz, Dieter A1 - Brandenburg, Ingo A1 - Menzel, Ralf T1 - Spectral broadening of the laser spectrum of gain-switched Ti:sapphire laser with nonlinear absorbers Y1 - 1999 ER - TY - JOUR A1 - Heuer, Axel A1 - Hodgson, N. A1 - Lorenz, Dieter A1 - Ostermeyer, Martin A1 - Menzel, Ralf T1 - Solid state lasers with high brightness via optical phase conjugation for micromachining Y1 - 1997 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Heuer, Axel A1 - Watermann, V. A1 - Menzel, Ralf T1 - Single rod Nd:laser with phase conjugating SBS-mirror and large transversal mode for average output powers above 20 Watts Y1 - 1996 ER -