Use this URL to cite or link to this record in EThOS:
Title: Optical trapping and optical sources for nanophotonics
Author: Head, Christopher Robin
Awarding Body: University of Southampton
Current Institution: University of Southampton
Date of Award: 2013
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Please try the link below.
Access from Institution:
In this thesis I describe work that I have done in two separate research areas. The first involves optical micro manipulation of nano-scale objects and their orientation. The second concerns the development of a semiconductor laser to provide high beam quality,average and peak power and short pulse durations. Optical tweezers are an excellent tool to manipulate nano scale objects in all three dimensions. An additional degree of control, the rotational alignment of assymetrical particles, is demonstrated by polarisation analysis of two photon induced fluorescence of the trapped and rotated semiconductor nanorods.Mode-locked vertical external-cavity surface emitting lasers (VECSELs) have recently achieved multi-watt average power levels. Nevertheless the need to optimize the gain structure design, in order to consistently obtain sub 200 fs pulse durations, still remains. The evolution of the intra-cavity power build-up transient is utilized for a novel spectro-temporal technique which allows for the extraction of the curvature of the gain spectrum during actual operation and enables the observation of the evolution of the gain spectrum during lasing build-up. In addition a method to obtain the total cavity loss via the combination of the power build-up transient and photo luminescence decline, during lasing onset is shown. The use of an amplified, femtosecond-pulsed and GHz repetition rate VECSEL to generate multi-watt average power supercontinuum in photonic crystal fibres (PCFs) is presented. Supercontinuum generation with GHz pulse repetition rates is of interest for frequency combs as the high repetition rate increases the mode spacing of the comb and energy per mode. Two different PCFs, one with an all-normal dispersion profile and one with a zero dispersion wavelength (ZDW) at 1040 nm, are pumped with the amplified VECSEL pulses generating spectral components over 200 nm and 500 nm, respectively. The thesis concludes with a proposal to use the advantages of both optical tweezers and VECSELs to analyse and resonantly excite the vibrational frequencies of single nano-scale objects.
Supervisor: Tropper, Anne Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: QC Physics