High-repetition-rate white-light pump-probe spectroscopy with a tapered fiber.
We have realized a 76 MHz white-light differential transmission spectroscopy system. The technique employs a Ti:sapphire laser oscillator and a tapered fiber to generate a white-light continuum spanning almost the full visible to near-infrared spectral range. Using acousto-optical modulation and subsequent lock-in detection, transient relative transmission changes as small as 10(-5) are detected. The method is applied to study the ultrafast gain dynamics of the active layer of a vertical-external-cavity surface-emitting laser based on a multiple-quantum-well structure.
Punke
M
M
Light Technology Institute and Center for Functional Nanostructures (CFN), Universität Karlsruhe (TH), Kaiserstrasse 12, D-76131 Karlsruhe, Germany. martin.punke@lti.uni-karlsruhe.de
Hoos
F
F
Karnutsch
C
C
Lemmer
U
U
Linder
N
N
Streubel
K
K