Details

Autor(en) / Beteiligte

• Pugžlys, A.
• Andriukaitis, G.
• Sidorov, D.
• Irshad, A.
• Baltuška, A.
• Lai, W. J.
• Phua, P. B.
• Su, L.
• Xu, J.
• Li, H.
• Li, R.
• Ališauskas, S.
• Marcinkevičius, A.
• Fermann, M. E.
• Giniūnas, L.
• Danielius, R.

Titel

Spectroscopy and lasing of cryogenically cooled Yb, Na:CaF2

Ist Teil von

• Applied physics. B, Lasers and optics, 2009-10, Vol.97 (2), p.339-350

Ort / Verlag

Berlin/Heidelberg: Springer-Verlag

Erscheinungsjahr

2009

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Absorption, photoluminescence and cw-lasing properties of a novel Na + -codoped Yb 3+ :CaF 2 laser crystal are investigated in the temperature range from 10 K to 290 K. Cryogenic cooling leads to the disappearance of the ground-state absorption in the spectral region above 1000 nm and a substantial increase of emission and absorption cross-sections. A particular advantage of the Yb 3+ , Na + -codoped CaF 2 crystal lies in the possibility of a direct pumping in the vicinity of the zero phonon line while nearly perfectly avoiding an overlap with the stimulated emission. Further advantages of the low-temperature operation are demonstrated by achieving a close to the theoretical limit slope efficiency of 92% in a cw-laser operation with an output coupler of 28%. By seeding stretched pulses from a femtosecond Yb fiber oscillator into a cryogenically cooled DPSS Yb 3+ , Na + :CaF 2 regenerative amplifier, we obtain >3-mJ pulses at a 1-kHz repetition rate with a spectral bandwidth exceeding 12 nm. The pulses are compressed with a single grating compressor to 173 fs as verified by SHG FROG. Shaping of the spectral amplitude of the seed and active control of the higher-order phase is shown to be crucial for obtaining sub-200-fs pulses at multi-mJ energies.