High-speed asynchronous optical sampling with sub-50fs time resolution.
We report an ultrafast time-domain spectroscopy system based on high-speed asynchronous optical sampling operating without mechanical scanner. The system uses two 1 GHz femtosecond oscillators that are offset-stabilized using high-bandwidth feedback electronics operating at the tenth repetition rate harmonics. Definition of the offset frequency, i.e. the time-delay scan rate, in the range of a few kilohertz is accomplished using direct-digital-synthesis electronics for the first time. The time-resolution of the system over the full available 1 ns time-delay window is determined by the laser pulse duration and is 45 fs. This represents a three-fold improvement compared to previous approaches where timing jitter was the limiting factor. Two showcase experiments are presented to verify the high time-resolution and sensitivity of the system.
Gebs
R
R
Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457, Germany. Raphael.Gebs@uni-konstanz.de
Klatt
G
G
Janke
C
C
Dekorsy
T
T
Bartels
A
A
D004581:Electronics / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005246:Feedback; D007834:Lasers; D009991:Oscillometry / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013057:Spectrum Analysis / Q000295:instrumentation*