@article{ElsnerUllmannHeueretal.2012, author = {Elsner, Robert and Ullmann, Roland and Heuer, Axel and Menzel, Ralf and Ostermeyer, Martin}, title = {Two-dimensional modeling of transient gain gratings in saturable gain media}, series = {OPTICS EXPRESS}, volume = {20}, journal = {OPTICS EXPRESS}, number = {7}, publisher = {OPTICAL SOC AMER}, address = {WASHINGTON}, issn = {1094-4087}, doi = {10.1364/OE.20.006887}, pages = {6887 -- 6896}, year = {2012}, abstract = {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}, 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{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{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{KappeOstermeyerMenzel2005, author = {Kappe, Philip and Ostermeyer, Martin and Menzel, Ralf}, title = {Active mode locking of a phase-conjugating SBS-laser oscillator}, issn = {0946-2171}, year = {2005}, abstract = {We present a flashlamp-pumped Nd: YAG laser simultaneously emitting pulse structures on microsecond, nanosecond and picosecond time scales. Within a microsecond flashlamp pump pulse a nonlinear reflector based on stimulated Brillouin scattering (SBS) generates several Q-switch pulses. The phase-conjugating effect of the SBS reflector provides a compensation of phase distortions generated inside the laser rod, resulting in transverse fundamental mode operation. Additional acousto-optic loss modulation inside the resonator leads to mode locking. As a result, each Q-switch pulse is subdivided into several picosecond pulses. Energies of up to 2 mJ for the mode-locked pulses with durations between 220 and 800 ps are demonstrated. The wide variability of the laser's temporal output parameters as well as its high beam quality make it a splendid tool for fundamental research in laser materials processing}, language = {en} } @article{KappeOstermeyerMenzel2005, author = {Kappe, Philip and Ostermeyer, Martin and Menzel, Ralf}, title = {Active mode locking of a phase-conjugating SBS-laser oscillator}, issn = {0946-2171}, year = {2005}, 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{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{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{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} }