Spectral broadening and temporal compression of â¼ 100 fs pulses in air-filled hollow core capillary fibers.
Opt Express
; 22(1): 1143-51, 2014 Jan 13.
Article
in En
| MEDLINE
| ID: mdl-24515074
ABSTRACT
We experimentally study the spectral broadening of intense, â¼ 100 femtosecond laser pulses at 785 nm coupled into different kinds of hollow core capillary fibers, all filled with air at ambient pressure. Differently from observations in other gases, the spectra are broadened with a strong red-shift due to highly efficient intrapulse Raman scattering. Numerical simulations show that such spectra can be explained only by increasing the Raman fraction of the third order nonlinearity close to 100%. Experimentally, these broadened and red-shifted pulses do not generally allow for straightforward compression using, for example, standard chirped mirrors. However, using special hollow fibers that are internally coated with silver and polymer we obtain pulse durations in the sub-20 fs regime with energies up to 300 µJ.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Opt Express
Journal subject:
OFTALMOLOGIA
Year:
2014
Type:
Article