Abstracts Category : Other

A Method to Dramatically Decrease the Required Depletion Power of STED Super-Resolution Microscopy and High Power Operation of NSOM Probes

by Daniel McBride

A versatile STED microscope using a supercontinuum light source for selecting various excitation and depletion wavelengths needed for different fluorescent dyes was designed and built. Using a 0.9 NA microscope objective and 100 nm diameter beads, 90 nm de-convoluted lateral super-resolution was achieved. A major drawback of traditional STED microscopy is the high depletion power required, which alters sample integrity and causes dye bleaching. A new version that should dramatically decrease the required depletion power is proposed and built. This version uses a common vortex phase plate for both the excitation and depletion beams which also improves mechanical stability of the overlapping focal spots. Rigorous electromagnetic and rate equation analysis shows that the required depletion optical power is decreased by a factor of about six in comparison with traditional method for achieving the same lateral super-resolution. In a separate project, in order to introduce more optical power into a NSOM probe without damaging the probe, epoxy heat sinks were fabricated on the probe tip. Optical imaging and optical power measurements were used to verify that the NSOM probe was not damaged when 405 nm light, at an input power of 21.4 mW, was coupled into the NSOM probe. The NSOM probe was used to ex-pose though 93 nm thick photoresist. The maximum scan rate was approximately 300 ?m/sec with a 100 nm aperture NSOM probe.Advisors/Committee Members: Su, Chin B (advisor), Kameoka, Jun (committee member), Yeh, Alvin (committee member), Han, Arum (committee member).