A method of initializing a phase-change optical information recording medium is provided, using an optical system incorporating a semiconductor laser device. The laser device is characterized by a specified spatial power distribution. In a spatial distribution of the laser power focused on the recording medium in the direction perpendicular to guide tracks, the laser device preferably has an average smaller in both end regions of the spatial distribution, which have each 10% of the width at half maximum of the distribution, than the average in the center region of the full width at half maximum of the distribution.

The invention proposes a technique for measuring chromatic dispersion in an optical communication line transmitting an optical signal at a predetermined optical wavelength. The technique comprises determining the sign of chromatic dispersion and includes introducing controlled changes of wavelength around the predetermined wavelength, monitoring the optical signal that has passed said line, and obtaining a first and a second signals, wherein the first signal reflects changes of the carrier wavelength, and the second signal reflects changes of delay of the optical signal transmitted via the line. The two signals are compared and the chromatic dispersion sign is determined based on the phase difference there-between.

A device for the measurement of chemical and/or biological samples, in particular by means of luminescence spectroscopy, comprises an irradiation unit (12), a sample receiver (10), at least one optical unit (30) and a detector unit (40). Electromagnetic radiation of various wavelength ranges and/or polarisations are led to the sample (10) from the irradiation unit (12). The colour marker in the sample (10), which contains at least one colour marker, is stimulated into producing luminescence and gives off light. The emitted light is led by means of an optical unit in the direction of an optical unit. The light emitted by the colour markers is detected by detectors (42,44,46, 48) in the detector unit. According to the invention, the measurement results may be improved on the irradiation unit (12) generating a pulsed irradiation. The irradiation unit is thus preferably controlled by a control unit (18) in such a way that the irradiation pulses impinge on the sample (10) in a temporal sequence.

Disclosed is a silver halide photographic light-sensitive material having a support containing a filler and/or an undercoat layer containing a clay compound coated with an organic substance between the support and an emulsion layer or between the support and a back layer. The silver halide photographic light-sensitive material shows good dimensional stability in a processing system.

An apparatus includes an optical keyboard and an optical input device controlled by a moving object. The input device has at least one diode laser and photo diode for supplying at least one measuring beam to a device window and for receiving radiation reflected by the object placed on the window. The input device may be integrated in the keyboard such that the measuring beam is guided via the positions of the keys to the window.

A method of providing a surface of a material with an image, includes applying to the surface an image sheet included (i) a flexible layer of a Shape Memory Polymer, and (ii) an image bonded to said layer by means of an image key coat. The image sheet is bonded to the surface by means of an adhesive and a process which involves heating of the Shape Memory Polymer to a temperature above its Glass Transition Temperature.

The probe comprises a light source (20), means for shaping (24, 25, 21) the beam emitted by said light source and the beam coming from a surface arranged close to a target distance, an optical detector unit (22), comprising a pinhole diaphragm (26) and a photoelectric detector (28), providing a voltage peak (31) when said surface is at said target distance and further comprising a diaphragm (27) with a hole larger than said pinhole and a photoelectric detector (29), providing a voltage greater than that produced by said detection sensor (28), except when said surface is a the target distance. The method uses the probe to measure the thickness of an optical lens.