In an apparatus for optically reading a target based on a light reflected from the target, a light source has a first optical axis and operates to emit light. An imaging optical system has a second optical axis. The imaging optical system is arranged so that the reflected light enters into the imaging optical system. A photodetector has an active area so that the imaging optical system focuses the reflected light on the active area of the photodetector. A light guide member is arranged between t...

An optically active color filter for controlling the color of light produced by a light source. The color filter includes an optically active device positioned between a linear polarizer and an adjustable position linear polarizer whose orientation can be controlled mechanically or electrically. In a preferred embodiment, the optically active device contains a liquid optically active substance such as high maltose corn syrup. The optically active color filter may be used for controlling the colo...

An optically detectable security marker for emitting light at a pre-selected wavelength. The marker comprises a rare earth dopant and a carrier incorporating the rare earth dopant. The interaction of the carrier and the dopant is such that the fluorescent fingerprint of the marker is different from that of the rare earth dopant. The marker may be incorporated into a plurality of items, such as fluids, for example paint, fuel or ink, and laminar products such as paper or banknotes or credit cards...

Operation of a power-by-light valve (15) by a source (11) along an optical fibre (13) is monitored by means of optical sensors (14) from which light passes back along fibre (13) to monitoring and processing units (16, 17). The sensors (14) include fibre bragg gratings (41, 43) for detecting differential pressure across diaphragms (42) and for detecting temperature. At the input end, an optical coupler (12) supplies sensor signals to units (16, 17) which can control source (11) via a signal (32).

A device for optical examination of biological materials using radiation of a selected wavelength includes a substrate having a first surface and a second surface opposite to the first surface. The first surface includes a dense array of micro-optical elements arranged to provide increased intensity radiation or evanescent radiation. The first surface is in close proximity to the biological material being examined.

Stripe-domain light deflectors are used within a lasing cavity. Magnetic trol of the deflectors permits tuning of the laser light to any wavelength in the range of light present.

A beam of light from a light source is reflected by a polyhedral mirror which is continuously rotating in a constant speed around its axis. The reflected beam sweeps on an object and passes a predetermined point of the object surface. A dispersed light from the point is formed into a beam through a set of slits and reaches a light detector. The polyhedral mirror has a plurality of mirror surfaces each of which is spaced at a distance from the rotary axis thereof, different from the adjacent mirr...

Optically active sulfonates of allethrolone of the formula ##STR1## wherein X is selected from the group consisting of alkyl of 1 to 3 carbon atoms and phenyl optionally substituted in the para position with a member selected from the group consisting of methyl, fluorine, chlorine and bromine with an (R) or (S) configuration which are useful for obtaining optically active allethrolone of antipodal configuration and process for their preparation.

A beam of light from a light source is reflected by a polyhedron mirror which is continuously rotating around its axis. The reflected beam sweeps on an object and passes a predetermined point of the object surface. A dispersed light from the point is formed into a beam through a set of slits and reaches into a light detector. The polyhedron mirror has a plurality of mirror surfaces each of which is spaced at an independent distance from the rotary axis thereof. The distance between the predeterm...

Asymmetric synthesis of optically active 3,7,11-trimethyl-dodecan-1-ol, an intermediate for producing optically active vitamin E, from isovaleraldehyde or prenal including intermediates in this synthesis.