Gires-Tournois-Interferometer mirrors are used for pulse compression in femtosecond lasers such as Yb:YAG - or Yb: KGW- lasers. LAYERTEC offers GTI mirrors also for the Ti:Sapphire wavelength range and for wavelengths up to 1600nm. Compared to prism compressors GTI mirrors reduce the intra-cavity losses resulting in higher output power of the laser.
The mirror pair shows a very smooth average GDD spectrum, although the single mirrors exhibit considerable GDD oscillations.
Measured and calculated GDD - curves match very well which proves the reliability of the coating process.

• GDD between – 200fs² and –2000fs²
• Very high reflectivity
• Measured LIDT 0.1 J/cm²
• Centre wavelength, bandwidth and GDD according to customer specification.
  Please note that bandwidth and GDD are closely connected. A high value of negative GDD results in a very narrow bandwidth.
• Spectral tolerance 1% of centre wavelength
  GTI - mirrors with a GDD up to –500 fs² are designed for a bandwidth of λ > 20 nm and will meet the specification even if the centre wavelength is 1% apart from the design wavelength. At higher GDD-values it is favourable to design the laser so that the GTI - mirror can be tilted by ± 10° to adjust the mirror for its best performance.
• In house design calculation and measurement capabilities (GDD 250 – 1700 nm, R-measurement by CRD at several wavelengths in the VIS and NIR)