Oblique illumination in petrographic microscope work

Oblique Illumination Stereoscopy in the Shadow Electron Microscope

The point projection or shadow electron microscope [1] is primarily used as a convergent-beam electron diffraction camera [2]. In this mode the specimen is at the same height as the convergent-beam (C.B.) source, i.e., the image of the original source which is formed in the vicinity of the back focal plane of the objective lens. The complimentary operation of the instrument as an underfocussed ...

Lens axicons in oblique illumination.

Lens axicons, i.e., lenses or lens systems designed to work like axicons, can be a simple and inexpensive way of generating the characteristic axicon focal line. In the design of most lens axicons, only on-axis properties have been considered. We present the design of a lens axicon with improved off-axis characteristics. It is constructed from a singlet lens but with a double-pass feature that ...

The Role of the Petrographic Microscope in Criminal Investigations

Microwave Imaging under Oblique Illumination

Microwave imaging based on inverse scattering problem has been attracting many interests in the microwave society. Among some major technical challenges, the ill-posed, multi-dimensional inversion algorithm and the complicated measurement setup are critical ones that prevent it from practical applications. In this paper, we experimentally investigate the performance of the subspace-based optimi...

A new method for oblique microscopical illumination.

THE purpose of the technique described in this paper is to provide the easiest possible means of controlling the direction and degree of obliquity of the light used to illuminate microscopical objects. The method is applicable when striations or other regularly-repeated markings on objects are situated so close together that, with axial illumination, the diffraction-spectrum they produce lies p...