TY - JOUR A1 - Strasser, A A1 - Ostermeyer, Martin T1 - Improving the brightness of side pumped power amplifiers by using core doped ceramic rods N2 - In side pumped laser head geometries good extraction of energy has to be weighted against diffraction effects of the amplified beam. Beam clipping at the aperture of laser rods can be avoided by using an undoped cladding around the doped core. The wings of e. g. Gaussian beams can be accommodated in the cladding. Phase distortion by the refractive index step of the rod can be compensated by a phase conjugating mirror in double pass configuration. In our proof of principle experiment the brightness of the beam from core doped amplifier rods was shown to be doubled compared to a conventional rod of the same outer diameter. (c) 2006 Optical Society of America Y1 - 2006 ER - TY - JOUR A1 - Räder, Andy A1 - Eisert, Jens A1 - Wilkens, Martin A1 - Schmidt, Robert A1 - Micka, Bettina A1 - Ostermeyer, Martin A1 - Zill, Rüdiger A1 - Baur, Jürgen A1 - Schmidt, Renate A1 - Leppin, Karin A1 - Slotowski, Agnes A1 - Resch-Esser, Ursula T1 - Portal = Albert Einsteins Erbe: Uni-Physiker forschen weiter BT - Die Potsdamer Universitätszeitung N2 - Aus dem Inhalt: - Albert Einsteins Erbe: Uni-Physiker forschen weiter - Uni-Studiengang im europäischen Exzellenzprogramm - Sternenstaubsammler - Mit Einfallsreichtum gegen den Trend T3 - Portal: Das Potsdamer Universitätsmagazin - 01-03/2005 Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-439846 SN - 1618-6893 IS - 01-03/2005 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Waltinger, Thomas A1 - Gregor, Markus T1 - Frequency stabilization of a Q-switched Nd:YAG laser oscillator with stability better 300 kHz following an rf- sideband scheme N2 - A frequency stabilization scheme following the Pound-Drever-Hall technique modified with a sample and hold circuit has been applied to a Q-switched diode-pumped Nd:YAG ring oscillator. The high-power ring is injection seeded by a monolithic non-planar ring laser oscillator (NPRO). The slave oscillator emits pulses of 23 ns duration and 20 mJ pulse energy with almost diffraction limited beam quality (M-2 = 1.2) at a repetition rate of 400 Hz. The short-term fluctuation of the center frequency from pulse to pulse is 290 kHz. The oscillator is designed for applications within lidar measurements. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00304018 U6 - https://doi.org/10.1016/j.optcom.2009.04.063 SN - 0030-4018 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Puhlmann, Dirk A1 - Korn, Dietmar T1 - Quantum diffraction of biphotons at a blazed grating N2 - Correlations between photons are interesting for a number of applications and concepts in metrology, in particular for resolution improvements in different methods of quantum imaging. We demonstrate the application of a blazed grating for the characterization of the degree of spatial correlation of biphotons. The biphotons are generated by type II parametric downconversion. Compared to an ordinary transmission grating, a blazed grating shows a high diffraction efficiency only for a single order of diffraction. Thus, higher intensities in the Fraunhofer far field behind the grating, and easier photon counting, can be achieved. The distribution of the two-photon rate in the Fraunhofer far field of the blazed grating can show one additional order of diffraction with a visibility related to the degree of correlation of the biphotons. The number of spatial modes that are populated by the biphoton beam can be directly altered in our experiments. The relation of the spatial mode order of the photon propagation to the observable degree of spatial correlation of the biphotons is investigated and related to the Schmidt number of spatially entangled modes. Y1 - 2009 UR - http://www.opticsinfobase.org/journalinfo.cfm?journal=2 SN - 0740-3224 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Mudge, Damien A1 - Veitch, Peter John A1 - Munch, Jesper T1 - Thermally induced birefringence in Nd : YAG slab lasers N2 - We study thermally induced birefringence in crystalline Nd:YAG zigzag slab lasers and the associated depolarization losses. The optimum crystallographic orientation of the zigzag slab within the Nd:YAG boule and photoelastic effects in crystalline Nd:YAG slabs are briefly discussed. The depolarization is evaluated using the temperature and stress distributions, calculated using a finite element model, for realistically pumped and cooled slabs of finite dimensions. Jones matrices are then used to calculate the depolarization of the zigzag laser mode. We compare the predictions with measurements of depolarization, and suggest useful criteria for the design of the gain media for such lasers. Y1 - 2006 UR - http://www.opticsinfobase.org/ U6 - https://doi.org/10.1364/AO.45.005368 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Mittler, Kay A1 - Menzel, Ralf T1 - Q switch and longitudinal modes of a laser oscillator with a stimulated-Brillouin-scattering mirror Y1 - 1999 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Menzel, Ralf T1 - Laser resonators with brillouin mirrors JF - Phase conjugate laser optics Y1 - 2004 SN - 0-471-43957-6 PB - Wiley CY - Hoboken, NJ ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Menzel, Ralf T1 - 34 Watt flash lamp pumped single rod ND:YAG laser with 1.2 * DL beam quality via special resonator design BT - Vierunddreißig Watt flash lamp pumped single rod ND:YAG laser with 1.2 * DL beam quality via special resonator design Y1 - 1997 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Menzel, Ralf T1 - 50 Watt average output power with 1.2*DL beam quality from a single rod Nd:YALO laser with phase-conjugating SBS mirror BT - Fünfzig Watt average output power with 1.2*DL beam quality from a single rod Nd:YALO laser with phase- conjugating SBS mirror Y1 - 1999 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Menzel, Ralf T1 - 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 Y1 - 1999 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Lorenz, Dieter A1 - Menzel, Ralf T1 - Nd-laser oscillators with phase-conjugating SBS mirrors for high average output powers and fundamental mode operation Y1 - 1997 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 - Ostermeyer, Martin A1 - Korn, Dietmar A1 - Puhlmann, Dirk A1 - Henkel, Carsten A1 - Eisert, Jens T1 - Two-dimensional characterization of spatially entangled photon pairs N2 - We characterize the entanglement in position and momentum of photon pairs generated in type-II parametric down- conversion. Coincidence maps of the photon positions in the near-field and far-field planes are observed in two transverse dimensions using scanning fiber probes. We estimate the covariance matrix of an effective two-mode system and apply criteria for entanglement based on covariance matrices to certify space-momentum entanglement. The role of higher- order spatial modes for observing spatial entanglement between the two photons is discussed. Y1 - 2009 UR - http://www.informaworld.com/openurl?genre=journal&issn=0950-0340 U6 - https://doi.org/10.1080/09500340903359962 SN - 0950-0340 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Klemz, Guido A1 - Menzel, Ralf T1 - Double rod Nd:YAG laser with 180 W average output and diffraction limited beam quality via path-matched birefringence compensation Y1 - 2002 SN - 0-8194-4368-9 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Klemz, Guido A1 - Kubina, P. A1 - Menzel, Ralf T1 - Enhanced brightness and extraction efficiency of Nd:YAG rod lasers resulting in 180 W output power with M2<1.2 Y1 - 2005 SN - 1-557-52697-4 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Klemz, Guido A1 - Kubina, P. A1 - Menzel, Ralf T1 - Quasi-continuous-wave birefringence-compensated single- and double-rod Nd : YAG lasers Y1 - 2002 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Klemz, Guido A1 - Heuer, Axel A1 - Menzel, Ralf T1 - High Brightness Double and Single Rod Nd:YAG Laser Oscillators with up to 180 W and M2 < 1.2 Y1 - 2002 ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Kappe, Philip A1 - Menzel, Ralf A1 - Wulfmeyer, Volker T1 - 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 N2 - 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 Y1 - 2005 SN - 0003-6935 ER - TY - BOOK A1 - Ostermeyer, Martin A1 - Kappe, Philip A1 - Menzel, Ralf A1 - Wulfmeyer, Volker T1 - 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 N2 - 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 Y1 - 2005 ER - TY - BOOK A1 - Ostermeyer, Martin A1 - Kappe, Philip A1 - Menzel, Ralf A1 - Sommer, S. A1 - Dausinger, Friedrich T1 - Laser drilling in thin materials with bursts of ns-pulses generated by stimulated Brillouin scattering (SBS) N2 - A passively Q-switched laser with a nonlinear mirror on the basis of stimulated Brillouin scattering (SBS), generates bursts of pulses with a few 10 ns pulse duration and a separation between 20-90 mu s. Percussion drilling and trepanning are performed in different materials with 1 mm thickness. The optimum parameter set of these pulse trains with regard to the burr height and ablation rate is investigated. Differences in the processing results between single pulse and multi pulse structures are discussed. In addition the laser allowed for transiently mode locked operation. Results for mode locked and merely Q-switched operation were compared Y1 - 2005 ER -