@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{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}
}