Manipulation of molecular motion using a high-energy chirped laser system.
Doctoral thesis, UCL (University College London).
This thesis reports on the development of a laser system for the manipulation of molecules using the optical dipole force. The centre-of-mass motion of molecules within the deep optical lattices created by the laser system, was probed using coherent Rayleigh scattering (CRS) and compared with simulations of these processes. The laser system was constructed to produce two, temporally coincident, pulsed beams with durations of hundreds of nanoseconds. The frequency difference between the two beams was controlled to be on the order of 1 GHz. This frequency control was produced by the construction of a low power ( 20 mW) Nd:YVO4 microchiptype laser which was frequency chirped by rapidly changing cavity length via an intra-cavity electro-optic crystal. The deleterious effects of intensity modulation induced by this process, were overcome by the design of an injection locking system with a free running semiconductor diode laser. This master slave laser system was pulse amplified to the required intensity in a fibre amplifier and a Nd:YAG flashlamp pumped amplifier system with a total gain of 109 maintaining the frequency characteristics of the low power laser system. The motion of molecules trapped in the optical lattice produced by the laser system was probed using CRS. Long pulse CRS was performed on xenon and octane gases utilising 100-200 ns pulses with a flat-top profile.
|Title:||Manipulation of molecular motion using a high-energy chirped laser system|
|Open access status:||An open access version is available from UCL Discovery|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Physics and Astronomy|
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