@article{MenzelHeuerPuhlmannetal.2013,
  author    = {Menzel, Ralf and Heuer, Axel and Puhlmann, Dirk and Dechoum, K. and Hillery, M. and Spaehn, M. J. A. and Schleich, W. P.},
  title     = {A two-photon double-slit experiment},
  series = {Journal of modern optics},
  volume    = {60},
  journal   = {Journal of modern optics},
  number    = {1},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {Abingdon},
  issn      = {0950-0340},
  doi       = {10.1080/09500340.2012.746400},
  pages     = {86 -- 94},
  year      = {2013},
  abstract  = {We employ a photon pair created by spontaneous parametric down conversion (SPDC) where the pump laser is in the TEM01 mode to perform a Young's double-slit experiment. The signal photon illuminates the two slits and displays interference fringes in the far-field while the idler photon measured in the near-field in coincidence with the signal photon provides us with which-slit' information. We explain the results of these experiments with the help of an analytical expression for the second-order correlation function derived from an elementary model of SPDC. Our experiment emphasizes the crucial role of the mode function in the quantum theory of radiation.},
  language  = {en}
}
@article{GarzSandmannRadingetal.2012,
  author    = {Garz, Andreas and Sandmann, Michael and Rading, Michael and Ramm, Sascha and Menzel, Ralf and Steup, Martin},
  title     = {Cell-to-cell diversity in a synchronized chlamydomonas culture as revealed by single-cell analyses},
  series = {Biophysical journal},
  volume    = {103},
  journal   = {Biophysical journal},
  number    = {5},
  publisher = {Cell Press},
  address   = {Cambridge},
  issn      = {0006-3495},
  doi       = {10.1016/j.bpj.2012.07.026},
  pages     = {1078 -- 1086},
  year      = {2012},
  abstract  = {In a synchronized photoautotrophic culture of Chlamydomonas reinhardtii, cell size, cell number, and the averaged starch content were determined throughout the light-dark cycle. For single-cell analyses, the relative cellular starch was quantified by measuring the second harmonic generation (SHG). In destained cells, amylopectin essentially represents the only biophotonic structure. As revealed by various validation procedures, SHG signal intensities are a reliable relative measure of the cellular starch content. During photosynthesis-driven starch biosynthesis, synchronized Chlamydomonas cells possess an unexpected cell-to-cell diversity both in size and starch content, but the starch-related heterogeneity largely exceeds that of size. The cellular volume, starch content, and amount of starch/cell volume obey lognormal distributions. Starch degradation was initiated by inhibiting the photosynthetic electron transport in illuminated cells or by darkening. Under both conditions, the averaged rate of starch degradation is almost constant, but it is higher in illuminated than in darkened cells. At the single-cell level, rates of starch degradation largely differ but are unrelated to the initial cellular starch content. A rate equation describing the cellular starch degradation},
  language  = {en}
}
@article{MenzelPuhlmannHeueretal.2012,
  author    = {Menzel, Ralf and Puhlmann, Dirk and Heuer, Axel and Schleich, Wolfgang P.},
  title     = {Wave-particle dualism and complementarity unraveled by a different mode},
  series = {Proceedings of the National Academy of Sciences of the United States of America},
  volume    = {109},
  journal   = {Proceedings of the National Academy of Sciences of the United States of America},
  number    = {24},
  publisher = {National Acad. of Sciences},
  address   = {Washington},
  issn      = {0027-8424},
  doi       = {10.1073/pnas.1201271109},
  pages     = {9314 -- 9319},
  year      = {2012},
  abstract  = {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.},
  language  = {en}
}
@article{HeuerSagahtiJechowetal.2012,
  author    = {Heuer, Axel and Sagahti, A. and Jechow, Andreas and Skoczowsky, D. and Menzel, Ralf},
  title     = {Multi-wavelength, high spatial brightness operation of a phase-locked stripe-array diode laser},
  series = {Laser physics},
  volume    = {22},
  journal   = {Laser physics},
  number    = {1},
  publisher = {Pleiades Publ.},
  address   = {New York},
  issn      = {1054-660X},
  doi       = {10.1134/S1054660X12010057},
  pages     = {160 -- 164},
  year      = {2012},
  abstract  = {Stable continuous wave multi-wavelength operation of a stripe-array diode laser with an externalcavity spectral beam combining geometry is presented. In this setup each emitter of the stripe-array is forced to operate at a different wavelength, which leads to a decoupling between the usually phase-locked emitters. With a reflective diffraction grating with a period of 300 lines per mm, 33 equidistant laser lines around a center wavelength of 978 nm were realized, spanning a spectral range of 26 nm. With this novel approach near-diffraction limited emission with a beam quality of M (2) < 1.2 and an output power of 450 mW was achieved. This laser light source can be used for applications requiring low temporal but high spatial coherence.},
  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{SkoczowskyJechowStuermeretal.2010,
  author    = {Skoczowsky, Danilo and Jechow, Andreas and St{\"u}rmer, Herbert and Poßner, Torsten and Sacher, Joachim and Menzel, Ralf},
  title     = {Quasi-monolithic ring resonator for efficient frequency doubling of an external cavity diode laser},
  issn      = {0946-2171},
  doi       = {10.1007/s00340-009-3802-7},
  year      = {2010},
  abstract  = {A quasi-monolithic second-harmonic-generation ring resonator assembled with miniaturized components is presented. The ring contains a 10-mm-long bulk periodically poled lithium niobate crystal for second-harmonic generation, four plane mirrors and two gradient-index lenses. All parts are mounted on a glass substrate with an overall size of 19.5 mmx8.5 mmx4 mm. As pump source a broad-area laser diode operated in an external resonator with Littrow arrangement is utilized. This external cavity diode laser provides near diffraction limited, narrow-bandwidth emission with an optical output power of 450 mW at a wavelength of 976 nm. Locking of the diode laser emission to the resonance frequency of the ring cavity was achieved by an optical self-injection locking technique. With this setup more than 126 mW of diffraction-limited blue light at 488 nm could be generated. The opto-optical conversion efficiency was 28\% and a wall plug efficiency better than 5.5\% could be achieved.},
  language  = {en}
}
@article{JechowLichtnerMenzeletal.2009,
  author    = {Jechow, Andreas and Lichtner, Mark and Menzel, Ralf and Radziunas, Mindaugas and Skoczowsky, Danilo and Vladimirov, Andrei G.},
  title     = {Stripe-array diode-laser in an off-axis external cavity : theory and experiment},
  issn      = {1094-4087},
  doi       = {10.1364/OE.17.019599},
  year      = {2009},
  abstract  = {Stripe-array diode lasers naturally operate in an anti-phase supermode. This produces a sharp double lobe far field at angles {\~n}a 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.},
  language  = {en}
}
@article{JechowLichtnerMenzeletal.2009,
  author    = {Jechow, Andreas and Lichtner, Mark and Menzel, Ralf and Radziunas, Mindaugas and Skoczowsky, Danilo and Vladimirov, Andrei G.},
  title     = {Stripe-array diode-laser in an off-axis external cavity : theory and experiment},
  issn      = {1094-4087},
  doi       = {10.1364/OE.17.019599},
  year      = {2009},
  abstract  = {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.},
  language  = {en}
}
@article{Menzel2007,
  author    = {Menzel, Ralf},
  title     = {Photonics : linear and nonlinear interactions of laser light and matter},
  publisher = {Springer},
  address   = {Berlin},
  isbn      = {978-540-67074-2},
  pages     = {1024 S.},
  year      = {2007},
  language  = {en}
}
@article{JechowRaabMenzel2006,
  author    = {Jechow, Andreas and Raab, Volker and Menzel, Ralf},
  title     = {High cw power using an external cavity for spectral beam combining of diode laser-bar emission},
  issn      = {0003-6935},
  doi       = {10.1364/AO.45.003545},
  year      = {2006},
  abstract  = {In extension to known concepts of wavelength-multiplexing diode laser arrays, a new external cavity is presented. The setup simultaneously improves the beam quality of each single emitter of a standard 25 emitter broad-area stripe laser bar and spectrally superimposes the 25 beams into one. By using this external resonator in an "off-axis" arrangement, beam qualities of M-slow(2) < 14 and M-fast(2) < 3 with optical powers in excess of 10 W in cw operation are obtained.},
  language  = {en}
}