Femtosecond infrared pulses tunable from 9 to 18 mum at an 88-MHz repetition rate.
Femtosecond mid-infrared laser pulses that are continuously tunable in the wavelength range from 9 to 18mum are demonstrated. These nearly bandwidth-limited pulses are generated by phase-matched difference-frequency mixing within the broad spectrum of 20-fs pulses from a mode-locked Ti:sapphire laser in GaSe. A direct determination of the pulse duration at 11.5mum gives a value of 140 fs. The average mid-infrared power of 1muW is ~100 times greater than that for infrared generation by non-phase-matched optical rectification.
Kaindl
R A
RA
Smith
D C
DC
Joschko
M
M
Hasselbeck
M P
MP
Woerner
M
M
Elsaesser
T
T