Advanced terahertz electric near-field measurements at sub-wavelength diameter metallic apertures.
Using terahertz-light excitation, we have measured with sub-wavelength spatial, and sub-cycle temporal resolution the time- and frequency-dependent electric-field and surface-charge density in the vicinity of small metallic holes. In addition to a singularity like concentration of the electric field near the hole edges, we observe, that holes can act as differential operators whose near-field output is the time-derivative of the incident electric field. Our results confirm the well-known predictions made by Bouwkamp, Philips Res. Rep. 5, 321-332 (1950), and reveal, with unprecedented detail, what physically happens when light passes through a small hole.
Faculty of Applied Physics, Department of Imaging Science and Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
A J L
AJ
Adam
J M
JM
Brok
M A
MA
Seo
K J
KJ
Ahn
D S
DS
Kim
J H
JH
Kang
Q H
QH
Park
M
M
Nagel
P C M
PC
Planken
D002627:Chemistry, Physical / Q000379:methods; D004560:Electricity; D004563:Electrochemistry / Q000379:methods; D004867:Equipment Design; D008670:Metals / Q000737:chemistry*; D008853:Microscopy / Q000379:methods*; D015233:Models, Statistical; D008962:Models, Theoretical; D055095:Optics and Photonics; D012542:Scattering, Radiation; D013053:Spectrophotometry / Q000379:methods*; D013059:Spectrum Analysis, Raman; D013997:Time Factors
D008670:Metals