Nanoscale optical microscopy in the vectorial focusing regime

Bessel beams: Effects of polarization

“…The transverse electric beam (TE1) has a central lobe with a width (harmonic mean over all orientations) even narrower than for the radially polarized case. The beam cross-section is asymmetric, but it has been demonstrated that multiple images can be used to give resolution equivalent to the minor axis [28]. Alternatively, an axially symmetric beam with substantially circularly polarization can be generated using illumination that is azimuthally polarized with a phase singularity, giving an axially symmetric central lobe narrower than that for radial polarization.…”

Solid immersion lens applications for nanophotonic devices

“…This was attributed to a new ability to perform systematic axial scanning and thus an ability to localise the focus of the beam in the component layer of the chip more accurately. Recently, we have reported SIL-enhanced polarization-sensitive imaging which, under certain conditions, surpasses conventional scalar diffraction limited performance as described by Sparrow's resolution criteria [3]. Under such SIL-induced extreme NA conditions the resulting focal-plane intensity distribution is strongly asymmetric and cannot be described correctly by scalar diffraction theory because the polarization direction of the incident light must be taken into account.…”

“…Subsequently, we have demonstrated, using imaging at 1530 nm, optical resolutions approaching ~100 nm [3] by implementing TOBIC microscopy using an s-SIL. We used the s-SIL modality because we are interested in resolving circuit features located around 100 µm below the backside surface of the silicon die.…”

“…Since its invention, the SIL has been exploited in several nanoscale technologies, including semiconductor integrated-circuit (IC) inspection [1][2][3], nanoscale spectroscopy [4,5], optical data storage [6,7] and photolithography [8], yet the benefits the SIL has introduced in these fields have received poor coverage. Therefore, in this paper we aim to review the theoretical aspects of the SIL and to discuss recent demonstrations of SIL-enhanced technologies in nanophotonics.…”

70 nm resolution in subsurface optical imaging of silicon integrated-circuits using pupil-function engineering

“…This asymmetry in the focal spot distribution leads to different resolutions along orthogonal directions in an image, and recently we reported the first evidence of this effect in a real image. 6 A further enhancement in resolution can be achieved by manipulating the irradiance distribution in the pupil-plane of the lens so as to reduce the dimensions of the focal spot below those obtained in the clear-pupil case. In particular, the use of annular pupil-plane apertures in the tight-focusing regime has been the subject of a number of theoretical investigations, which collectively highlighted the advantages of single and multiple-zone annular apertures for improving the lateral resolution and manipulating the focal volume and depth-of-focus through the isolation of the illuminating high spatial frequencies.…”