Abstract: The invention relates to a method and an apparatus for the investigation of a sample material by multiple sample light spots (501) generated by evanescent waves. An array of source light spots (510) is generated by a multi-spot generator, e.g. a multi-mode interferometer (106), and mapped onto sample light spots (501) in a sample layer (302) by (micro-)lenses (202, 203) or by the Talbot effect. The input light (504) of the source light spots (510) is shaped such that all of it is totally internally reflected at the interface between a transparent carrier plate (301) and the sample layer (302). Thus the sample light spots (501) consist of evanescent waves only and are restricted to a limited volume. In a preferred application, fluorescence stimulated in the sample light spots (501) is detected with spatial resolution by a CCD array (401).

Abstract: A method for controlling an optical disc drive apparatus (1) which comprises: light beam generating means (31) for generating a plurality of N optical beams (32(i)); means (33, 34, 37) for focusing said beams in respective focus spots (F(i)); at least one adjustable member (34) for axially displacing said focus spots; comprises the step of calculating an optimum setting (ZOPTIMUM) for the adjustable member (34), such that the out-of-focus condition for the optical system (30) as a whole is as small as possible. The position of the adjustable member (34) may be controlled to be substantially equal to the said optimum setting (ZOPTIMUM). Or, one specific beam is maintained in a focus condition, the beam having number m=mOPT selected according to mOPT=±INTEGERSQUARE{(N?1)/(2?2)} in case N is odd or mOPT=±INTEGERROUND IN?(N?2)/8) in case N is even.

Abstract: A controllable optical lens system comprises a chamber housing first and second fluids, the interface between the fluids defining a lens surface. An electrode controls the shape of the lens surface and has first and second electrodes. The current supplied by a power source to the electrode arrangement is monitored, and the charge supplied is derived. The voltage on one of the electrodes of the electrode arrangement is also monitored. A desired lens power is used to derive a control value for controlling the total charge to be supplied to the electrode arrangement. The drive scheme is independent of some of the lens characteristics, and is more easily implemented than a feedback control system using capacitive sensing.

Abstract: The invention relates to an optical system comprising a fluid chamber 1 and a birefringent part. The fluid chamber comprises first and second fluids 10, 12 having different indices of refraction, the interface between the fluids forming a meniscus 14. The birefringent part is capable of varying characteristics of a first radiation beam 3b and a second radiation beam 3c, the first and second radiation beams having different polarisations. Variation in the configuration of the meniscus causes variation in the characteristics of the first radiation beam and the second radiation beam. Variation in the configuration of the meniscus may be controlled by electrowetting.

Abstract: A variable focus lens of the type including a first fluid (A) and a second fluid (B), the fluids being immiscible and having different indices of refraction wherein the lens function of the variable focus lens can be selectively controlled. The refractive indices of the two respective fluids (A) and (B) are different, and it is highly advantageous if the difference between these refractive indices is relatively high, in order to obtain a good zoom factor. Many oils with a high refractive index (approximately above 1.7) are not colourless, but instead tend to be yellow. However, this causes colour changes in the image of an object compared with the object itself. This problem is solved by correcting or compensating for the resultant change of colour of an image of an object, compared with the object itself, caused by the use of a non-colourless fluid as the first and/or second fluid in a variable focus lens of the above-mentioned type.

Abstract: A storage container for at least one readable and/or writable data disk (D) having a ferro-magnetic hub (H) in its centre. The container comprises at least one panel (1) having a surface (2) for accommodating the disk. The surface includes magnetic material (4) in a position to enable alignment of the disk hub therewith for holding said disk adjacent to the surface. The surface (2) comprises guiding a centring member (3) which positioned about the magnetic material (4) so as to surround the disk (D) at least partially when in stored position adjacent said surface. The invention enables a convenient storage and removal of the disk with low risk of damaging the disk.

Abstract: The invention relates to an optical holographic device for reading out a data page of a holographic medium (106). The holographic device comprises a pixelated detector (114) having detector elements organized in a staggered structure.

Abstract: The invention relates a to an optical holographic device for reading out a data page recorded in a holographic medium (106). The device comprises means for receiving the holographic medium, means for imaging the data page and means (114) for detecting the imaged data page. It also comprises, between the receiving means and the detecting means, an electro-optical system (200, 300, 400) which magnification can be changed by application of a voltage between electrodes.

Abstract: The invention relates to an optical holographic device for reading out a data page recorded in a holographic medium (106). The device comprises means (104, 105) for forming an imaged data page from the data page. The imaged data page comprises imaged data bits (a, b, c, d) having a first size (s1) in a direction (D). The device comprises means for detecting (114) the imaged data page. The detecting means comprise detector elements having a second size (s2) in the direction (D). The second size is larger than the first size. The device comprises displacement means (200) for displacing the imaged data page in the direction (D) with respect to the detecting means so as to scan the imaged data page.

Abstract: The invention relates to an optical holographic device for reading out a data page recorded in a holographic medium (106). The device comprises means (104, 105) for forming an imaged data page, means for detecting (114) the imaged data page, means for detecting a Moiré pattern in the detected imaged data page and means for modifying the imaged data page as a function of the Moiré pattern.

Abstract: An arrangement for read-out of information stored on an optical information carrier (30) is disclosed. Light from a master laser (10) is reflected from the information carrier (30) and injected into a slave laser (20) in polarization state that is generally orthogonal to the free-running polarization of the slave laser. The amount of injected light required to switch the polarization of the slave laser depends upon the wavelength difference between the master laser and the free-running slave laser. By controlling the wavelength difference between the two lasers, the arrangement is capable of reading different gray-levels from the information carrier (30).

Abstract: The invention relates to an optical holographic device for reading out a data page recorded in a holographic medium (202). The data page comprises data bits. The device comprises means (200) for producing a radiation beam having an intensity, means (201) for directing the radiation beam towards the holographic medium so as to image the data page, means (203) for detecting a set of imaged data bits in the imaged data page, means (204) for counting, among the set of imaged data bits, the number of imaged data bits having a predetermined data state and means (205) for modifying the intensity as a function of this number.

Abstract: The invention relates to an optical holographic device for recording data bits in a holographic medium (106). The device comprises a light modulator (103) with addressable elements (301), each having an area and at least one optically active sub-area (302) smaller than said area, means for directing a radiation beam towards the light modulator to form an encoded radiation beam so as to record at least first and second data bits (401, 402) in the holographic medium, means (200) for displacing the encoded radiation beam with respect to the holographic medium and means for controlling the displacing means so as to record a third data (403) bit between the first and second data bits.

Abstract: An optical scanning device for scanning an optical record carrier comprising an information layer. Crosstalk cancellation is provided using a phase modulating element (40, 140) for generating a non-rotationally-symmetric phase profile in a subsidiary radiation beam. The phase profile varies with an azimuthal angle measured about the optical axis of the beam portion, the phase profile varying such that successively different phases are introduced in at least five locations which are each at successive azimuthal angles (?1, ?2, ?N) and each at a given radial distance from the optical axis, wherein the phase profile is such that the phases introduced, when taken in modulo 2? form, successively cycle through 0 to 2? at least twice, whereby the subsidiary beam spot is provided with an intensity distribution on the information layer which overlaps that of the side-lobe of the main beam spot.

Abstract: The invention provides a tool to select reliable organic LED devices, where the risk for failure before the end of its lifetime is low. This tool comprises the steps of: i) subjecting the device to a high electric field over the electroluminescent layer. This leads to a division of the devices into two, clearly separated, populations, namely one population with a low leakage current (current through the electroluminescent layer in reverse voltage operation) and one population with a high leakage current. In this step, the first population is selected in accordance with a current criterion. ii) detecting instabilities in the leakage current, referred to as noise. It has been established that these instabilities arise in particular at reverse driving voltages between 1 and 10 Volts. These instabilities are a measure of the occurrence of early failures during operation. In this step, the devices are selected in accordance with a noise criterion.