Abstract: A beam polarizer device for splitting an unpolarized beam of incident radiation into first and second beams of different polarizations. The beam polarizer comprises a birefringent cell interposed between a pair of parallel sides of first and second prisms made of an optically transparent material. The birefringent cell is formed of an oriented organic material having a desired orientation of its optical axis relative to the sides of the prisms enclosing the birefringent cell therebetween. The organic material has substantially different refraction indices n1 and n2 for light components of, respectively, two different orientations of electric fields relative to the direction of propagation of a beam impinging onto the birefringent cell while propagating inside the first prism. The optically transparent material has a refraction index n3 which is substantially equal to the greatest one between the refraction indices n1 and n2.

Abstract: A device for directing a primary particle beam at a sample and detecting particles in accordance with the emergence of particles from the sample. The device comprises a source for generating the primary beam and a passage leading from the source to the sample. It has one end towards the source and a second end towards the sample and, alongside the passage, is placed a particle detector having a face for receiving particles to be detected. At the first end of the passage is placed a cover suitable for generating secondary electrodes, which has a central aperture for admitting the primary beam. The particle detector is orientated with the face for receiving particles towards the cover.

Abstract: A holographic optical device includes a light transmissive substrate carrying first and second laternally separated holographic optical elements. The first holographic optical element diffracts incident light into the substrate where it is trapped by internal reflection so that light impinges more than once at different angles at different locations on at least one of the first and second holographic optical elements with a significantly higher efficiency for one angle of incidence. The second holographic optical element diffracts light out of the substrate. The second holographic optical element may be a display hologram for displaying a three-dimensional image.

Abstract: A particle detector for an electron microscope, a mass spectrometer or the like comprises a single flat plate electron multiplier such as a micro-channel plate or a micro-sphere plate followed by a scintillator. The use of the electron multiplier prior to the scintillator compensates for lack of efficiency in passing photons from the scintillator. The output voltage of the scintillator can be freely set.

Abstract: A holographic optical device having a light transmissive substrate with a first holographic optical element carried by the substrate, and a second holographic optical element also carried by the substrate but laterally offset from the first holographic optical element. The first holographic optical element diffracts waves from each data point in a display source into a collimated plane wave such that the plane wave is trapped inside the substrate by internal reflection, and the first holographic optical element also corrects field aberrations over the entire field of view by being recorded using at least one aspheric wavefront. The second holographic optical element diffracts the trapped plane waves out of the substrate.