@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}
}
@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{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{KappeMenzelOstermeyer2006,
  author    = {Kappe, Philip and Menzel, Ralf and Ostermeyer, Martin},
  title     = {Analysis of the temporal and spectral output properties of a mode-locked and Q-switched laser oscillator with a nonlinear mirror based on stimulated Brillouin scattering},
  issn      = {1050-2947},
  doi       = {10.1103/Physreva.74.013809},
  year      = {2006},
  abstract  = {The emission dynamics of a mode-locked laser oscillator with a nonlinear mirror based on stimulated Brillouin scattering (SBS) has been investigated with regard to its spectrum and to its intensity distribution. The investigation was carried out experimentally as well as by numerical simulations. The laser yields trains of pulses with measured durations of 410 ps and energies of the single pulse of up to 2 mJ. Two theoretical models describing the complex emission dynamics of a mode-locked SBS-laser oscillator are introduced. The first model consists of spectrally resolved laser rate equations and thus describes the mode locking in the frequency domain by the superposition of the longitudinal resonator modes. The SBS-Q-switch is incorporated by a phenomenological description of the time dependent SBS reflectivity. Numerical simulations based on this model yield the evolution of a few 100 longitudinal laser modes and the corresponding intensity distribution during the course of a Q-switch pulse with 10-ps resolution. The influences of the different components on the spectrum and thus on the pulse duration will be discussed. The second model describes all occurring dynamics in the time domain providing easy access to the study of misalignment on the output dynamics. Results of numerical simulations of both models and measurement results are compared},
  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{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{EichlerHaaseMenzel1994,
  author    = {Eichler, Hans Joachim and Haase, Alfred and Menzel, Ralf},
  title     = {SBS-Phase Conjugation for Thermal Lens Compensation in 100 Watt Average Power Solid-State Lasers},
  year      = {1994},
  language  = {en}
}
@article{LueckMenzelSander1994,
  author    = {Lueck, H. and Menzel, Ralf and Sander, Rolf},
  title     = {Inherent sample heating and temperature calibration in excited state absorption (ESA) measurements between room temperature and 77 kelvin},
  year      = {1994},
  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{EichlerMenzelSanderetal.1995,
  author    = {Eichler, Hans Joachim and Menzel, Ralf and Sander, Rolf and Schulzke, M. and Schwartz, J.},
  title     = {SBS at different wavelengths between 308 and 725 nm},
  year      = {1995},
  language  = {en}
}
@article{EichlerHaaseMenzel1995,
  author    = {Eichler, Hans Joachim and Haase, Alfred and Menzel, Ralf},
  title     = {Power enhancement and application of a Nd:YALO rod amplifier with a phase conjugating mirror},
  year      = {1995},
  language  = {en}
}
@article{MenzelEichlerGeinitzetal.1995,
  author    = {Menzel, Ralf and Eichler, Hans Joachim and Geinitz, E. and Haase, Alfred and Scherrer, R.},
  title     = {Neodymium-laser with SBS phase conjugation for high beam quality},
  year      = {1995},
  language  = {en}
}
@article{EichlerHaaseMenzel1995,
  author    = {Eichler, Hans Joachim and Haase, Alfred and Menzel, Ralf},
  title     = {Power enhancement and application of a Nd:YALO rod amplifier with a phase conjugating mirror},
  year      = {1995},
  language  = {en}
}
@article{EichlerHaaseMenzel1995,
  author    = {Eichler, Hans Joachim and Haase, Alfred and Menzel, Ralf},
  title     = {100 watt average output power 1.2*diffraction limited beam from pulsed neodym single rod amplifier with SBS- phaseconjugation},
  year      = {1995},
  language  = {en}
}
@article{HeuerMenzelOstermeyer1996,
  author    = {Heuer, Axel and Menzel, Ralf and Ostermeyer, Martin},
  title     = {Power tunable Nd-oscillators with diffraction limited beams via SBS phase conjugation},
  year      = {1996},
  language  = {en}
}
@article{OstermeyerHeuerMenzel1996,
  author    = {Ostermeyer, Martin and Heuer, Axel and Menzel, Ralf},
  title     = {Q-switching of Nd-lasers with high repetition rates by SBS phase conjugation},
  year      = {1996},
  language  = {en}
}
@article{OstermeyerHeuerWatermannetal.1996,
  author    = {Ostermeyer, Martin and Heuer, Axel and Watermann, V. and Menzel, Ralf},
  title     = {Resonators with phase conjugating SBS-mirror for solid state lasers with high output powers},
  year      = {1996},
  language  = {en}
}
@article{OstermeyerHeuerWatermannetal.1996,
  author    = {Ostermeyer, Martin and Heuer, Axel and Watermann, V. and Menzel, Ralf},
  title     = {Single rod Nd:laser with phase conjugating SBS-mirror and large transversal mode for average output powers above 20 Watts},
  year      = {1996},
  language  = {en}
}
@article{SanderHerrmannMenzel1996,
  author    = {Sander, Rolf and Herrmann, V. and Menzel, Ralf},
  title     = {Transient absorption spectra and bleaching of 4'-n-Pentyl-4-Cyanoterphenyl in Cyclohexane : determination of cross sections and recovery times},
  year      = {1996},
  language  = {en}
}
@article{EichlerHaaseMenzel1996,
  author    = {Eichler, Hans Joachim and Haase, Alfred and Menzel, Ralf},
  title     = {High beam quality of a single rod neodym amplifier by SBS-phase conjugation up to 140 watt average output},
  year      = {1996},
  language  = {en}
}
@article{OstermeyerMenzel1997,
  author    = {Ostermeyer, Martin and Menzel, Ralf},
  title     = {34 Watt flash lamp pumped single rod ND:YAG laser with 1.2 * DL beam quality via special resonator design},
  year      = {1997},
  language  = {en}
}
@article{HeuerHodgsonLorenzetal.1997,
  author    = {Heuer, Axel and Hodgson, N. and Lorenz, Dieter and Ostermeyer, Martin and Menzel, Ralf},
  title     = {Solid state lasers with high brightness via optical phase conjugation for micromachining},
  year      = {1997},
  language  = {en}
}
@article{MittlerOstermeyerHeueretal.1997,
  author    = {Mittler, Kay and Ostermeyer, Martin and Heuer, Axel and Menzel, Ralf},
  title     = {Longitudinal mode structure of Nd-lasers with phase conjugating mirrors based on stimulated Brillouin scattering in different materials},
  year      = {1997},
  language  = {en}
}
@article{OstermeyerLorenzMenzel1997,
  author    = {Ostermeyer, Martin and Lorenz, Dieter and Menzel, Ralf},
  title     = {Nd-laser oscillators with phase-conjugating SBS mirrors for high average output powers and fundamental mode operation},
  year      = {1997},
  language  = {en}
}
@article{OstermeyerLorenzHodgsonetal.1997,
  author    = {Ostermeyer, Martin and Lorenz, Dieter and Hodgson, N. and Menzel, Ralf},
  title     = {Transverse Modes in Laser Resonators with Phase Conjugating Mirror Based on Stimulated Brillouin Scattering (SBS)},
  year      = {1997},
  language  = {en}
}
@article{LorenzMenzel1998,
  author    = {Lorenz, Dieter and Menzel, Ralf},
  title     = {Broadband operation of frequency doubled Cr4+:YAG laser with high beam quality},
  year      = {1998},
  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}
}
@article{OstermeyerHeuerMenzel1998,
  author    = {Ostermeyer, Martin and Heuer, Axel and Menzel, Ralf},
  title     = {27 Watt average output power with 1.2*DL beam quality from a single rod Nd:YAG-Laser with phase conjugating SBS- mirror},
  year      = {1998},
  language  = {en}
}
@article{OstermeyerHodgsonMenzel1998,
  author    = {Ostermeyer, Martin and Hodgson, N. and Menzel, Ralf},
  title     = {High-power, fundamental mode Nd:YALO laser using a phase-conjugate resonator based on SBS},
  year      = {1998},
  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{HeuerMenzel1998,
  author    = {Heuer, Axel and Menzel, Ralf},
  title     = {Phase conjugating SBS-mirror for low powers and reflectivities above 90 \% in an internally tapered optical fiber},
  year      = {1998},
  language  = {en}
}
@article{HeuerSchultheissHodgsonetal.1999,
  author    = {Heuer, Axel and Schultheiss, J. and Hodgson, N. and Kurths, J{\"u}rgen and Menzel, Ralf and Raab, Volker},
  title     = {Transverse effects in phase conjugate laser mirrors based on stimulated brillouin scattering},
  year      = {1999},
  language  = {en}
}
@article{LorenzBrandenburgMenzel1999,
  author    = {Lorenz, Dieter and Brandenburg, Ingo and Menzel, Ralf},
  title     = {Spectral broadening of the laser spectrum of gain-switched Ti:sapphire laser with nonlinear absorbers},
  year      = {1999},
  language  = {en}
}
@article{MittlerLorenzMenzel1999,
  author    = {Mittler, Kay and Lorenz, Dieter and Menzel, Ralf},
  title     = {Broadband operation of a gain-switched Ti:sapphire laser for measurements with the coherence radar},
  issn      = {0277-786X},
  year      = {1999},
  language  = {en}
}
@article{MittlerLorenzMenzel1999,
  author    = {Mittler, Kay and Lorenz, Dieter and Menzel, Ralf},
  title     = {Time-resolved measurements of the spectra of a broadband laser used as light source for the coherence radar},
  year      = {1999},
  language  = {en}
}
@article{OstermeyerMittlerMenzel1999,
  author    = {Ostermeyer, Martin and Mittler, Kay and Menzel, Ralf},
  title     = {Q switch and longitudinal modes of a laser oscillator with a stimulated-Brillouin-scattering mirror},
  year      = {1999},
  language  = {en}
}
@article{OstermeyerMenzel1999,
  author    = {Ostermeyer, Martin and Menzel, Ralf},
  title     = {Single rod efficient Nd:YAG and Nd:YALO-lasers with average output powers of 46 and 47 W in diffraction limited beams with M2 < 1.2 and 100 W with M2 < 3.7},
  year      = {1999},
  language  = {en}
}
@article{OstermeyerMenzel1999,
  author    = {Ostermeyer, Martin and Menzel, Ralf},
  title     = {50 Watt average output power with 1.2*DL beam quality from a single rod Nd:YALO laser with phase-conjugating SBS mirror},
  year      = {1999},
  language  = {en}
}
@article{MittlerLorenzMenzel1999,
  author    = {Mittler, Kay and Lorenz, Dieter and Menzel, Ralf},
  title     = {Time resolved emission spectra of a broadband ns-laser with 0.5 W average output power used as light source for the coherence radar},
  year      = {1999},
  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{HeuerMenzel2000,
  author    = {Heuer, Axel and Menzel, Ralf},
  title     = {Temporal features of SBS phase conjugation},
  isbn      = {0-8194-3545-7},
  year      = {2000},
  language  = {en}
}
@article{HeuerMenzel2000,
  author    = {Heuer, Axel and Menzel, Ralf},
  title     = {Low threshold SBS phase conjugation for quasi-cw laser systems},
  year      = {2000},
  language  = {en}
}
@article{RaabUllnerMenzel2000,
  author    = {Raab, Volker and Ullner, Ekkehard and Menzel, Ralf},
  title     = {Novel External Resonators for High Power Diode Lasers with Improved Beam Quality},
  year      = {2000},
  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{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{HaenischHeuerMenzel2001,
  author    = {H{\"a}nisch, Christoph and Heuer, Axel and Menzel, Ralf},
  title     = {Threshold reduction of stimulated Brillouin scattering (SBS) using fiber loop schemes},
  year      = {2001},
  language  = {en}
}
@article{AfshaarvahidHeuerMenzeletal.2001,
  author    = {Afshaarvahid, Shahraam and Heuer, Axel and Menzel, Ralf and Munch, Jesper},
  title     = {Temporal structure of stimulated-Brillouin-scattering reflectivity considering transversal-mode development},
  year      = {2001},
  language  = {en}
}
@article{Menzel2001,
  author    = {Menzel, Ralf},
  title     = {Photonics : Linear and nonlinear interactions of laser light and matter},
  publisher = {Springer},
  address   = {Berlin},
  isbn      = {3-540-67074-2},
  pages     = {873 S.},
  year      = {2001},
  language  = {en}
}
@article{SpitzvonSeggernGrunwaldtetal.2002,
  author    = {Spitz, Christian and von Seggern, David and Grunwaldt, Gisela and Menzel, Ralf},
  title     = {Biochemical Diagnostics by Excited State Absorption Spectroscopy},
  isbn      = {0-8194-4365-4},
  year      = {2002},
  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}
}