Instrumentation of Ultrafast Spectroscopy


where else can one play in the dark
Passive Mode-Locking is the result of the Kerr Effect, which is based on the non-linear intensity
dependent index of refraction. When combined with an appropriately placed slit and a small
perturbation, one can achieve pulses of approximately 10 femtoseconds in duration!!!

saturated? not likely regenerative amplifier
Regenerative Amplification (above) and Multi-Pass Gain Amplification are the two
most common ways to produce usable pulses for Ultrafast Spectroscopy.


Ti:Sapphire Passive Mode-Locked Laser
safety glasses should be on at all times when using a class 4 laser!
Frequency And Time Obey A Fourier Relationship...


1000 to 500, 500 to 800 (and some)... cool alway read with ample lighting
In 1991, the "Self Locking by a Kerr Lens Effect" was observed by Scottish Scientists (U. Keller et al.) and henceforth,
the technical difficulties have been reduced with the advent of the "Ti:Sapphire Passive Mode Locked Laser"

The autocorrelator... 3 dozen things which can go wrong! The autocorrelator... 3 dozen things which can go wrong!
Degenerate pump-probe autocorrelation with 2nd harmonic generation!!!
Current
Research
Activities


chain axis time resolved impulsive excitation
Photoexcitations are generated in halide-bridged mixed-valence-linear chain complexes by exciting the intense optical intervalence charge transfer transition. The local excitations were time resolved producing details of both the vibrational and electronic dynamics.
Various
Personalities
Of Ultrafast
Spectroscopy




Adjustments Continue
Skills of Alignment
Minor Tweaking Needed


Observed Rise Time
Not Mode-Locking?


Additional Tweaking Needed
Spot Size Concerns
The Vasu Effect


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