Ultra-Violet Laser
Physics
Dr.
Ken Baldwin email: Kenneth.Baldwin@anu.edu.au
LINK TO UV
PULICATIONS
The UV Laser Physics Laboratory in
the Laser Physics Centre has two complementary
experimental research programmes based around a high power, pulsed
dye laser facility:
- Studies of fundamental nonlinear optical
processes, in collaboration with the Quantum Optics group in the
Faculties (Prof. Hans Bachor)
- The application of these techniques to the
high resolution VUV spectroscopy of atmospheric molecules, in
collaboration with theUV
Physics Unit in AMPL (Dr. Brenton Lewis and Dr. Stephen Gibson).
The nonlinear optics studies have centred on
the generation of several multiphoton excitation pathways in atomic
systems (mainly sodium), which interfere quantum mechanically to
produce both constructive and destructive effects. These
interferences can be used to enhance or diminish the nonlinear
process being monitored, such as four wave mixing or multiphoton
ionisation.
Highlights include
-
the demonstration of interference between
different four wave mixing processes using separate bound state
resonances, in which the sign and magnitude of the interference could
be controlled by varying the laser detuning from resonance
experimental investigation of laser induced continuum structures the
suppression of the AC Stark effect in two-photon resonant,
three-photon ionisation, caused by the introduction of a second laser
field which generates a competing four wave mixing pathway
One output of these nonlinear processes - the
generation of narrowband, tunable radiation in the vacuum ultraviolet
(VUV) spectrum - has been applied to the high resolution VUV
spectroscopic study of atmospheric molecules, primarily diatomic
oxygen.
Highlights include -
the use of stimulated Raman scattering, third
harmonic generation, and four wave mixing to carry out the highest
resolution studies of photoabsorption cross-sections for oxygen in
the VUV the observation of rotational edges and shape resonances near
the oxygen Schumann-Runge continuum the first characterisation of
isotopic differences in highly resolved rovibrational structure in O2
the discovery of two new states of oxygen.
Suggestions/Enquiries:Departmental Administrator
Date last modified: Fri, 20 Feb 1998