Berlin 2001 – scientific programme
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Q: Quantenoptik
Q 5: Generation of Short Pulses I
Q 5.6: Talk
Monday, April 2, 2001, 17:00–17:15, H 2013
Ultrabroadband generation and field-resolved detection of tunable femtosecond light pulses approaching the near infrared — •Florian Tauser, Rupert Huber, Andreas Brodschelm, Alfred Leitenstorfer, and Alfred Laubereau — Physikdepartment E11, TU München
Bandwidth-limited single-cycle light pulses in the far and mid infrared are generated by phase-matched optical rectification of 10 fs laser pulses. The exceptionally high nonlinearity
χ(2) of GaSe emitters allows for efficient frequency conversion. Tilting the GaSe crystal by the phase-matching angle, the central frequency of the transients is continuously tunable over a wide interval extending from the far infrared up to 45 THz ( λ ≈ 7 µ m) [1].
We directly monitor the electric field of the multi-THz pulses via free-space electro-optic sampling [2]. The use of extremely thin electro-optic sensors (d ≈ 10 µ m) enhances the bandwidth of this amplitude- and phase-resolving technique to above 100 THz (λ = 3 µ m), thus covering the entire far and mid infrared regime.
The described system opens up a wide field of novel linear and nonlinear
spectroscopic studies. In our first application, we directly observe the
temporal build-up of a plasma resonance in an intrinsic semiconductor after ultrafast optical excitation of charge carriers.
[1] R. Huber, A. Brodschelm, F. Tauser, and A. Leitenstorfer, Appl. Phys. Lett. 76, 3191 (2000)
[2] Q. Wu, and X.-C. Zhang, Appl. Phys. Lett. 70, 1784 (1997)