Title :
FDTD Analysis of a Flat Diffractive Optics with Sub-Reyleigh Limit Resolution in MM/THz Waveband
Author :
Minin, I.V. ; Minin, O.V. ; Gagnon ; Petosa
Author_Institution :
Novosibirsk State Tech. Univ., Novosibirsk
Abstract :
The focusing properties of phase correcting Fresnel lenses with small values of focal length-to-diameter (FID) and with focal lengths of two wavelengths or less are investigated. For these lenses, the paraxial approximation for the Rayleigh resolution criterion is no longer valid. For Fresnel lenses designed with F/D < 0.2 and F les lambda, spatial resolutions of less than 0.5lambda are possible, which is finer than what can typically be achieved for conventional (paraxial) designs. The spot beams in these cases are not quite axially symmetrical due to the presence of anti-symmetric field components, which vanish for larger values of F/D.
Keywords :
finite difference time-domain analysis; lenses; light diffraction; millimetre waves; optical focusing; submillimetre waves; FDTD; MM/THz waveband; Rayleigh resolution; anti-symmetric field; flat diffractive optics; focal length -to -diameter; focusing property; paraxial approximation; phase correcting Fresnel lens; sub-Rayleigh limit resolution; Finite difference methods; Fresnel reflection; Lenses; Microoptics; Optical design; Optical diffraction; Optical microscopy; Optical refraction; Spatial resolution; Time domain analysis;
Conference_Titel :
Infrared Millimeter Waves and 14th International Conference on Teraherz Electronics, 2006. IRMMW-THz 2006. Joint 31st International Conference on
Conference_Location :
Shanghai
Print_ISBN :
1-4244-0400-2
Electronic_ISBN :
1-4244-0400-2
DOI :
10.1109/ICIMW.2006.368378
