摘要:
A device for reading and/or writing a record carrier (13), the device comprising converging means (35, 45, 47, 106, 108) for focusing a radiation beam (27, 101) originating from a radiation source (25) on the record carrier (13). The converging means comprises polarization means (103) and a diffraction grating (107) of birefringent material. Dependent on the direction of polarization, the radiation beam (101) is focused on one of two possible surfaces corresponding to DVD and DVR, respectively. A diffraction grating (107) is present in a central area of the radiation beam (101) and causes diffraction of a first order for one direction of polarization of the radiation beam (101) and diffraction of a second, higher, order for a second direction of polarization of the radiation beam (101). The diffraction grating (107) is made of birefringent material.
摘要:
An optical scanning device (1) for scanning an information layer (4) of an optical record carrier (2), the device including a radiation source (11) for generating a radiation beam (12) and an objective system (18) for converging the radiation beam (12) on the information layer, the objective system (18) being characterized in that the ratio of the root mean square of the optical path difference's (OPD's) generated by the objective system at oblique beam entrance to the system satisfies the condition of formula (I) within the field of the objective system, where OPD(A31) is the contribution of the third order Zernike coma to the root mean square wavefront aberration and OPD(A51) is the contribution of the fifth order Zernike coma to the root mean square wavefront aberration.
摘要:
An optical scanning device (1) for scanning an information layer (4) of an optical record carrier (2), the device (1) comprising a radiation source (11) for generating a radiation beam (12, 15, 20) and an objective system (18) for converging the radiation beam on the information layer, the information layer being covered by a transparent layer (3) of thickness td and refractive index nd. The objective system comprises a lens formed of a single material. The lens satisfies the condition: Fomula (I), where t is the thickness of the lens, FWD is the free working distance between the lens (18) and the carrier (2), where t, td and FWD are expressed in millimeters, and where FWD+td/nd
摘要:
A device for scanning a first and second type of optical record carriers (2; 40) generates a first and a second radiation beam for scanning the first and second type of record carriers, respectively, the first radiation beam having a first numerical aperture larger than the second numerical aperture of the second radiation beam. The device includes a non-periodic phase structure that does not affect the first radiation beam. The phase structure introduces an amount of spherical aberration in the second radiation beam for scanning the second type of record carriers for compensating the difference in spherical aberration required for scanning through the different thickness of the transparent layer (3; 41) of the first and second type of record carriers (2, 40). To reduce the amount of stray light on the detection system (25) from rays in the second radiation beam having a numerical aperture larger than the second numerical aperture, the phase grating introduces a discontinuity in the gradient of the wavefront deviation it introduces in the second radiation beam. The discontinuity allows spatial filtering in the plane of the detection system (25) of the desired and undesired rays of the second radiation beam.
摘要:
An optical element (16) introduces a first wavefront deviation when a first radiation beam having a first wavelength passes through it and a second wavefront deviation when a second radiation beam having a second wavelength different from the first wavelength passes through it. One surface of the optical element comprises a phase structure in the form of annular areas (52, 53, 54, 55), the areas forming a non-periodic pattern of optical paths of different length. The optical paths for the first wavelength form the first wavefront deviation and the optical paths for the second wavelength form the second wavefront deviation, the difference between the two deviations being proportional to the difference between the first and second wavelength.
摘要:
An optical scanning device for scanning optical record carriers with radiation of a selected wavelength, the device including an objective lens, having an axial direction and a radial direction, and a phase structure which is non-periodic with respect to the radial direction, the non-periodic phase structure being arranged to compensate for comatic aberrations generated in the objective lens when an optical record carrier is read in a direction which is non-axial with respect to said objective lens, whereby an improved field of view is provided for said objective lens.
摘要:
An optical scanning device has a three element compound objective lens where a dual lens objective lens system is combined with a solid immersion lens to form an ultra high numerical aperture compound objective lens capable of reading from different information layers in a multilayer optical record carrier.
摘要:
A particle optical apparatus, such as an ion implantation apparatus, an Auger electron spectrometer, an XPS analysis apparatus, and the like, is provided with a radiation source by means of which a wafer or substrate brought into the apparatus can be bombarded by radiation providing for at least a positively charged surface layer of the wafer or substrate. The apparatus further comprises a charge neutralization device with means for providing secondary electron emission and transport means for transporting secondary electrons. This transport means device is provided with a hollow insulating structure for controlled electron transport based on secondary electron emission, particularly in the form of an electron fibre with electrodes at the entrance and exit. The exit of the electron fibre forms a clean secondary electron source.
摘要:
The present invention relates to an apparatus 100 and, a method and a computer program for determining a parameter indicative of a tissue type of an associated tissue 116. In particular, the invention relates to an apparatus 100 comprising a spectrometer 102, which spectrometer comprises a light source 104 and a detector 106, 108 arranged to measure an optical spectrum. This enables determination of a first parameter being indicative of a bile concentration. As the inventors of the present invention have made the insight that bile concentration may serve as a discriminative feature for different tissue types, the apparatus is arranged to determine a second parameter indicative of a tissue type based on a concentration of bile. According to a specific embodiment, the apparatus further comprises an interventional device 112.
摘要:
Re-calibration of pre-recorded images during interventions uses an interventional system including an imaging device providing images of an object, a needle device, and a processing device. The needle device includes a sensor for providing data corresponding to tissue properties. The processing device is configured to perform an overlay registration of pre-recorded images and live images provided by the imaging device, utilizing the data from the sensor. Thus, the accuracy of an overlay of images is increased.