Near-field scanning optical microscopy with laser trapping

This thesis is concerned with a comprehensive understanding of particle-trapped near-field scanning optical microscopy. This technique is unique in that it relies on the collection of scattered evanescent waves from a sample with a laser-trapped particle. In comparison with the other forms of near-field scanning optical microscopy with a\ud tapered fibre or a metallic needle probe, particle-trapped near-field scanning optical microscopy offers several advantages such as no need of distance control, high signal\ud collection efficiency, and easy replacement of a particle probe. In consideration of the major problems of particle-trapped near-field scanning optical microscopy such as low signal strength and low transverse scanning speed due to\ud the use of a dielectric particle, a two-dimensional laser-trapped metallic particle is proposed as a near-field probe for imaging