Introduction
These pages describe a high power, pulsed, injection seeded, narrow
bandwidth and continuously tunable optical parametric oscillator (OPO) based
on two β-barium borate (BBO) non-linear crystals. The OPO generates high
power transform limited nanosecond light pulses directly in the ranges 770
- 1050 nm and 535-675 nm. Various frequency doubling and mixing
schemes allow the range from 210-1050 nm to be covered. The bandwidth is
~ 130 MHz (0.004 cm-1) in the visible which translates
to a resolution for UV spectra of 0.01 cm-1. There are
only a few groups world-wide with this sort of capability and our system
is a much more practical source of narrow bandwidth light than alternatives.
We have recorded sub-Doppler spectra in the UV of PF, PH and other radicals.
The nuclear hyperfine structure revealed provides valuable insight into
the electronic structure and bonding in these radicals, and our work has
wider implications for electronic structure calculations as it provides
a very stringent test of the quality of calculated wavefunctions.
The work is funded by the Engineering and Physical Sciences Research Council (EPSRC), and these pages are based on the final reports for the grants involved.