Narrow-bandwidth picosecond pulses by spectral compression of femtosecond pulses in second-order nonlinear crystals.
We introduce a simple approach for the efficient generation of tunable narrow-bandwidth picosecond pulses synchronized to broadband femtosecond ones. Second harmonic generation in the presence of large group velocity mismatch between the interacting pulses transfers a large fraction of the energy of a broadband fundamental frequency pulse into a narrowband second harmonic one. Using a periodically poled stoichiometric lithium tantalate crystal coupled to an infrared optical parametric amplifier, we generated 200-nJ pulses with spectral width lower than 8.5 cm(-1) and tunability from 720 to 890 nm. Energy scaling and extension of the tuning range are straightforward.
Marangoni
M A
MA
Brida
D
D
Quintavalle
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M
Cirmi
G
G
Pigozzo
F M
FM
Manzoni
C
C
Baronio
F
F
Capobianco
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AD
Cerullo
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G