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VERSION:2.0
PRODID:-//RLASKEY//CALENDEROUS//EN
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METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20261021T063452Z
LAST-MODIFIED:20141121T205503Z
DTSTART:20141204T210000Z
DTEND:20141204T220000Z
UID:event1367@bu.edu
URL:http://physics.bu.edu/internal/events/show/1367
SUMMARY:Developing a Near-Field Scanning Optical Microscope for the Charact
	erization of Aluminium Nanoantennas
DESCRIPTION:Featuring Marc McGuigan\n\nPart of the PhD Final Oral Exams.\n\
	nDissertation Committee:  Bennett Goldberg\, Shyam Erramilli\, David Campbe
	ll\, Anna Swan\, James Rohlf\n\nAbstract:\nOptical antennas localize energy
	 from incoming electromagnetic waves that oscillate at visible frequencies.
	  Because optical wavelengths are smaller than radio wavelengths\, optical 
	antennas are substantially smaller than radio antennas – they are on the 
	order of tens or hundreds of nanometers\, where light-matter interactions a
	re described by charge density oscillations. The electromagnetic field resp
	onse of aluminum optical antennas can be studied using near-field scanning 
	optical microscopy.   \nThe spatial and intensity characteristics of the el
	ectromagnetic field response from an optical antenna are a function of the 
	antenna geometry and the light-matter interaction. This response will have 
	propagating and nonpropagating field components. Far-field microscopes can 
	measure the propagating components of the field\, but these components prov
	ide little information about features that are smaller than the diffraction
	 limit\, or about half the wavelength of the illuminating light. The nonpro
	pagating components of the field can provide more detailed and localized sp
	atial information\, but these components are difficult to measure because t
	heir amplitude decays exponentially as they move away from the sample. By i
	ntroducing a sharp probe into the focus\, near-field microscopes can scatte
	r nonpropagating field components into the far-field.\nOur system illuminat
	es the nanoantenna with laser light\, controls a sharp probe in the focus\,
	 and collects the scattered light. We have implemented a feedback system to
	 maintain the sub-50 nm probe-sample separation as the probe is scanned wit
	h respect to the sample. This feedback system allows us to acquire a high-r
	esolution surface profile image together with an optical image. The spatial
	 resolution of a near-field microscope is limited by the sharpness of the p
	robe and the ability to distinguish photons scattered by the presence of th
	e probe.  The optical antenna system has been modeled by approximating the 
	nanoscale aluminum antennas as a dipole orthogonal to the optical axis and 
	the probe as a dipole along the optical axis.\n\n![Marc](/resources/event-i
	mage/1367/ed851d5_small)
LOCATION:PRB 261\, 3 Cummington Mall\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
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