Abstract: The present disclosure provides a lens assembly. The lens assembly, includes at least one lens having a central part used for imaging and an edge part around the central part; and a shading unit in the at least one lens. The edge part depresses from an image side surface to an object side surface and forms a concave part for positioning the shading unit. In addition, the present disclosure further discloses a lens module including the lens assembly mentioned above.

Abstract: A non-invasive electrical stimulation device shapes an elongated electric field of effect that can be oriented parallel to a long nerve, such as a vagus nerve in a patient's neck, producing a desired physiological response in the patient. The stimulator comprises a source of electrical power, at least one electrode and a continuous electrically conducting medium in which the electrode(s) are in contact. The stimulation device is configured to produce a peak pulse voltage that is sufficient to produce a physiologically effective electric field in the vicinity of a target nerve, but not to substantially stimulate other nerves and muscles that lie between the vicinity of the target nerve and patient's skin. Current is passed through the electrodes in bursts of preferably five sinusoidal pulses, wherein each pulse within a burst has a duration of preferably 200 microseconds, and bursts repeat at preferably at 15-50 bursts per second.

Abstract: The present invention relates to a photomultiplier having a structure for making it possible to easily realize high detection accuracy and fine processing, and a method of manufacturing the same. The photomultiplier comprises an enclosure having an inside kept in a vacuum state, whereas a photocathode emitting electrons in response to incident light, an electron multiplier section multiplying in a cascading manner the electron emitted from the photocathode, and an anode for taking out a secondary electron generated in the electron multiplier section are arranged in the enclosure. A part of the enclosure is constructed by a glass substrate having a flat part, whereas each of the electron multiplier section and anode is two-dimensionally arranged on the flat part in the glass substrate.

Abstract: The present invention relates to a photomultiplier having a structure for making it possible to easily realize high detection accuracy and fine processing, and a method of manufacturing the same. The photomultiplier comprises an enclosure having an inside kept in a vacuum state, whereas a photocathode emitting electrons in response to incident light, an electron multiplier section multiplying in a cascading manner the electron emitted from the photocathode, and an anode for taking out a secondary electron generated in the electron multiplier section are arranged in the enclosure. A part of the enclosure is constructed by a glass substrate having a flat part, whereas each of the electron multiplier section and anode is two-dimensionally arranged on the flat part in the glass substrate.

Abstract: A photomultiplier tube including a casing having a glass substrate with a main surface made with an insulating material, dynodes having a 1st stage to an Nth stage which are arrayed to be spaced away sequentially from a first end side to a second end side on the main surface, a photocathode installed on the first end side to be spaced away from the 1st stage dynode to emit photoelectrons, and an anode part installed on the second end side to be spaced away from the Nth stage dynode, wherein a groove is formed between two adjacent dynodes on the main surface of the glass substrate, and the 1st stage to the Nth stage dynodes are fixed on raised parts adjacent to the grooves.

Abstract: A method and apparatus of obtaining a record of repetitive optical or other phenomena having durations in the picosecond range, comprising a circular scan electron tube to receive light pulses and convert them to electron images consisting with fast nanosecond electronic signals, a continuous wave light or other particle pulses, e.g. electron picosecond pulses, and a synchronizing mechanism arranged to synchronize the deflection of the electron image (images) in the tube (tubes) with the repetition rate of the incident pulse train. There is also provided a method and apparatus for digitization of a repetitive and random optical waveform with a bandwidth higher than 10 GHz.

Abstract: The present invention relates to a photomultiplier that realizes significant improvement of response time properties with a structure enabling mass production. In the sealed container, a photocathode, a dynode unit including at least one dynode set, and preferably dynode sets of two series, a focusing electrode unit arranged between the photocathode and the dynode unit are housed. The focusing electrode unit is set to the same potential as the second dynode arranged at a position where secondary electrons from said first dynode, which emits secondary electrons in response to incidence of photoelectrons, arrive, and is provided with partitioning plates partitioning the second dynode into two in a longitudinal direction of the second dynode.

Abstract: The present invention relates to a photomultiplier having a structure for making it possible to easily realize high detection accuracy and fine processing, and a method of manufacturing the same. The photomultiplier comprises an enclosure having an inside kept in a vacuum state, whereas a photocathode emitting electrons in response to incident light, an electron multiplier section multiplying in a cascading manner the electron emitted from the photocathode, and an anode for taking out a secondary electron generated in the electron multiplier section are arranged in the enclosure. A part of the enclosure is constructed by a glass substrate having a flat part, whereas each of the electron multiplier section and anode is two-dimensionally arranged on the flat part in the glass substrate.

Abstract: The present invention relates to a photomultiplier having a fine configuration capable of realizing stable detection accuracy. The photomultiplier has a housing whose inside is maintained vacuum, and a photocathode, an electron-multiplier section, and an anode are disposed in the housing. In particular, one or more control electrodes disposed in an internal space of the housing which surrounds the electron-multiplier section and the anode are electrically connected via one or more connection parts extending from an electron emission terminal of the electron-multiplier section.

Abstract: A vacuum vessel is configured by hermetically joining a faceplate to one end of a side tube and a stem to the other end via a tubular member. A photocathode, a focusing electrode, dynodes, a drawing electrode, and anodes are arranged within the vacuum vessel. The dynodes and the anodes have a plurality of channels in association with each other. The drawing electrode is placed on electrically-conductive supporting pins penetrating the stem. The dynodes are stacked with insulating members interposed between one another. Since the supporting pins and the insulating members are arranged coaxially, each electrode can be fixed by applying pressure in z-axis direction. At the same time, emission of light between the anodes and the drawing electrode can be suppressed, thereby enabling noise to be reduced.

Abstract: The present invention relates to a photomultiplier having a fine structure capable of realizing high detection accuracy by effectively suppressing cross talk among electron-multiplier channels. The photomultiplier comprises a housing whose inside is maintained vacuum, and, in the housing, a photocathode, an electron-multiplier section, and anodes are disposed. The electron-multiplier section has groove portions for cascade-multiplying photoelectrons as electron-multiplier channels, and the anodes are constituted by channel electrodes corresponding to the groove portions respectively defined by wall parts. In particular, at least parts of the respective channel electrodes are located in spaces sandwiched between pairs of wall parts defining the corresponding groove portions.

Abstract: A photomultiplier tube includes: a cathode, a plurality of dynodes, and an electron lens forming electrode. The cathode emits electrons in response to incident light. The plurality of dynodes multiplies electrons emitted from the cathode. The electron lens forming the electrode is disposed in a prescribed position in relation to an edge of a first dynode positioned in a first stage from the cathode and an edge of a second dynode positioned in a second stage from the cathode, and smoothes an equipotential surface in a space between the first dynode and the second dynode along a longitudinal direction of the first dynode. This structure improves time resolution in response to incident light.

Abstract: Electrons are prevented from being made incident onto an insulation part between dynodes to improve a withstand voltage.

Abstract: A gating large area hybrid photomultiplier tube that includes an envelope, a photocathode for emitting electrons in correspondence with incident light entering the envelope, a collecting anode having a semiconductor device which has an electron incident surface for receiving photoelectrons emitted from the photocathode, a gating grid for gating the photoelectrons emitted from the photocathode, an electron optical system for focusing and directing the photoelectrons generated by the photocathode toward the electron incident surface, and an ion target for collecting positive ions from the photoelectrons. The envelope has a first opening and a second opening; the photocathode is disposed at the first opening, while the collecting anode is disposed at the second opening of the envelope.

Abstract: A time-resolved measurement apparatus (100) reads a detection timing pulse from an MCP (24) in a front-side MCP stack (30) in a photomultiplier tube (14). A detection timing of a photon is determined based on this pulse. A principal component of this pulse is a potential rise pulse in response to the emission of photoelectrons from the MCP (24), and it has the positive polarity. On the other hand, when photoelectrons are incident on the front-side stack (30), a pulse of the negative polarity is generated to deform the waveform of the detection timing pulse. However, since the number of the photoelectrons incident on the front-side stack (30) is fewer than that of those incident on a rear-side stack (32), the negative component is small in the detection timing pulse. This results in enhancing the time precision of the time-resolved measurement.

Abstract: Light source and backlight module utilizing the same. The light source includes a hollow glass tube and an electrode disposed therein. The electrode comprises a bent surface, increasing surface area, thereby increasing light emission efficiency and reducing temperature.

Abstract: A photocathode, for generating electrons in response to incident photons in a photodetector, includes a base layer having a first lattice structure and an active layer having a second lattice structure and epitaxially formed on the base layer, the first and second lattice structures being sufficiently different to create a strain in the active layer with a corresponding piezoelectrically induced polarization field in the active layer, the active layer having a band gap energy corresponding to a desired photon energy.

Abstract: A vacuum vessel is configured by hermetically joining a faceplate (13) to one end of a side tube (15) and a stem (29) to the other end via a tubular member (31). A photocathode (14), a focusing electrode (17), dynodes (Dy1-Dy12), a drawing electrode (19), and anodes (25) are arranged within the vacuum vessel. The dynodes (Dy1-Dy12) and the anodes (25) have a plurality of channels in association with each other. The drawing electrode (19) is placed on electrically-conductive supporting pins (21) penetrating the stem (29). The dynodes (Dy1-Dy12) are stacked with insulating members (23) interposed between one another. Since the supporting pins (21) and the insulating members (23) are arranged coaxially, each electrode can be fixed by applying pressure in z-axis direction. At the same time, emission of light between the anodes (25) and the drawing electrode (19) can be suppressed, thereby enabling noise to be reduced.

Abstract: The present invention relates to a photomultiplier having a structure for performing a high gain and achieving a higher productivity in a state keeping or improving an excellent high-speed response. In the photomultiplier, an electron-multiplying unit accommodated in a sealed container has a structure that enables an integrated assembly of a focusing electrode, an accelerating electrode, a dynode unit, and an anode. Specifically, the focusing electrode has one or more notched portions to be grasped by a part of each of the insulating support members for grasping directly the dynode unit and so on when the focusing electrode itself is rotated around the tube axis of the sealed container. With this construction, the focusing electrode is fixed to the pair of insulating support members in a state that the focusing electrode is aligned with high accuracy by using the pair of insulating support member as a reference member.

Abstract: An inner surface of an electron-multiplier hole (14) includes a first curved surface (19a) and a second curved surface (19b) that face each other. The first curved surface (19a) extends from an edge of an input opening (14a) in such a way as to face the input opening (14a), and is shaped like a substantially circular arc having a predetermined radius. The second curved surface (19b) extends from an edge of an output opening (14b) in such a way as to face the output opening (14b), and is shaped like a substantially circular arc having a predetermined radius.

Abstract: A faceplate (F) for an image intensifier tube (10) for reducing veiling glare begins as a blank (36) of optical material of a desired glass composition having a shape that conforms substantially to a configuration of the faceplate (F) to be produced. An extraneous removable aperture step portion (54) is formed on the glass blank (36). The glass blank is blackened (41) and the aperture step portion (54) is removed creating a desired transmissive aperture (34) through the glass blank (36).

Abstract: A photomultiplier has a dynode cascade arranged radially rather than axially. Effective dynode area thereby can increase through the cascade, leading to improved linearity of response, and the axial length of the device can be reduced. The dynodes are sections of a set of toroids and may be formed as a layer of secondary emissive material such as caesiated antimony on a monolithic sintered cast or otherwise moulded or machined block of insulating material. This novel form of dynode construction can also be used in other photomultiplier or electron multiplier configurations.

Abstract: An inner surface of an electron-multiplier hole (14) includes a first curved surface (19a) and a second curved surface (19b) that face each other. The first curved surface (19a) extends from an edge of an input opening (14a) in such a way as to face the input opening (14a), and is shaped like a substantially circular arc having a predetermined radius. The second curved surface (19b) extends from an edge of an output opening (14b) in such a way as to face the output opening (14b), and is shaped like a substantially circular arc having a predetermined radius.

Abstract: Method and structure for temperature stabilization in semiconductor devices are disclosed. In one embodiment, a carbon-based polymer is deposited on top of an interconnect metal line in the semiconductor die where relatively large power dissipation is known to occur. Reduction of the range of temperature excursions in the semiconductor die is achieved since the polymer acts as a cushion to dampen the range of temperature excursions of the semiconductor die. During occurrence of power pulses in the semiconductor die, the polymer absorbs energy from the interconnect metal, and thus from the semiconductor devices that are connected to the interconnect metal, by expanding without a rise in the temperature of the polymer. The energy generated when power pulses are being dissipated in the semiconductor die does not result in a substantial rise in the temperature of the polymer.

Abstract: An improved microchannel plate (24) is disclosed. The microchannel plate has an input side (24a) and an output side (24b). A coating (32) is applied to the input side (24a) to increase secondary electron production and to prevent ions from leaving the microchannel plate (24) and damaging the photocathode (22).

Abstract: A microdynode electron multiplier provides numerous microchannels extending parallel to one another through a layered structure incorporating insulating spacer layers and dynode layers which either incorporate a conductive electrode layer or are contiguous with a conductive electrode layer. The dynode layers include materials with high electron emissivity. The dynode layers can be biased to different electrical potentials to provide a potential gradient along the length of each microchannel. Multi-stage electron multiplication provides high gain. The device desirably is formed as a monolithic, sealed structure with a cathode structure such as a photocathode and an anode structure. The device can provide a multi pixel imaging device of extremely high sensitivity and resolution.

Abstract: A vacuum diode with a high saturation current density and a rapid response time for the detection of electromagnetic radiation. This diode comprises a grid (6) in the shape of a cylinder and a photo-cathode (4) which extends along the axis (X) of the cylinder. The photo-cathode includes a part of the internal conductor of a coaxial cable (8), the external conductor and the electrically insulating material of the coaxial cable being removed opposite this part, and the grid is electrically connected to the external conductor of this coaxial cable, the internal and external conductors being coaxial. Application to the detection of visible, infra-red, ultra-violet and X radiation.

Abstract: There is disclosed a three draw technique for drawing optical fibers into various cross-sectional shapes. The process employs a glass tube and rod which are fed into a heated furnace. The viscosity of the glass decreases and the glass flows. The glass is pulled or drawn out of the furnace at a different rate than it is fed into the furnace. The resultant drawn fibers are stacked and the process is repeated two more times. By employing three drawing steps one can achieve extremely small fiber faces. The final draw step uses a hexagonal cross-section preform and fibers. From the first drawn fibers three geometrical shapes can be assembled and finally drawn into hexagonal shapes with round fibers which are triangles, rhombohedrials and half hex or trapezoidal shapes. These shapes maintain the hexagonal closely packed space providing the highest density per cross-section. With this high density there is less glass flowing to fill voids thereby reducing distortion within the fabricated MCP.

Abstract: An electron multiplier with a source for spontaneously generating electrons is used as an electron source for an ionization source in a mass spectrometer or the like. The electron multiplier can be a microchannel plate, in which case it produces a wide electron beam. The microchannel plate can be acid-leached to provide a surface for spontaneous generation of electrons, or the first strike surface can be coated with an alkali-containing material. The electron source can be tuned by providing an electrode for rejecting electrons having too high an energy and a grid for rejecting electrons having too low an energy.

Abstract: A photosensor comprises a cathode portion (111) sensitive to radiation and/or particles, an anode portion (114) receiving electrons, an evacuated channel (112, 113, 200) having the cathode portion attached to its one end portion in a vacuum-tight manner and the anode portion attached to its other end portion in a vacuum-tight manner, a conductive or semiconductive layer (107) at least partially covering the inner surface of the evacuated channel, wherein the channel is formed of a tubular member (106). A method of manufacturing a channel electron multiplier comprises the steps of forming a tubular member and a conductive or semiconductive layer at least on parts of its inner surface, forming an anode portion and sealing it to the tubular member, evacuating the tubular member, forming a cathode portion sensitive to radiation and/or particles, and sealing the cathode portion to the evacuated tubular member. The detector may at least partially be packed into a casting compound.

Abstract: A channel-type electron multiplier and a method and apparatus for rounding off the sharp circular edges, fissures and protrusions at the ends of the holes in the glass plate. In order to do this a temperature gradient is produced through the plate so that only a small portion is heated above the glass softening temperature. The plate thus does not collapse or melt. The said rounded edges improve performance by reducing field emission, noise and photocathode contamination. An electrically heated nichrome wire provides heat pulses at regular intervals. An alternative method utilizes an optical lap after core glass in the plate holes has been partially etched out.

Abstract: The present invention relates to a photocathode having a structure for improving the quantum efficiency and sharpening the absorption edge characteristic on the long wavelength side within the wavelength range of incident light to improve the photosensitivity, and an electron tube having the same. The photocathode according to the present invention comprises at least a p-type GaAlN layer for absorbing incident light to excite photoelectrons, a p-type GaN layer which covers the second major surface of the p-type GaAlN layer, the second major surface opposing a first major surface that faces a substrate, and a surface layer provided to sandwich the p-type GaN layer with the p-type GaAlN layer and mainly containing an alkali metal or an alkali metal oxide.

Abstract: In the electron multiplier assembly 27, a dynode unit 10 is constructed from a plurality of dynodes 9 laminated one on another. Each dynode 9 is formed with multichannels 12 which are separated from one another by channel-separating portions 14. A focusing electrode plate 16 is formed with multichannels 18 which are separated from one another by channel-separating electrodes 20 which are located in correspondence with the channel-separating portions 14 of the first stage dynode 9a. A plurality of anodes 7 are provided for receiving electrons multiplied at the dynode unit 10 in their corresponding channels 18. Each channel-separating electrode 20 is formed with an opening 21, at a position confronting the channel-separating portion 14 of the first stage dynode 9a, for transmitting electrons therethrough.

Abstract: The secondary emission characteristics of a microchannel plate of the type fabricated of lead oxide glass and activated by a hydrogen gas bake is stabilized by treating with another gas, such as hydrogen sulfide, at an elevated temperature.

Abstract: A field emission device with microchannel gain element provides a plurality of field emission or "cold" cathodes formed generally into an array. The cold cathodes are typically modulated by a grid having a driving voltage. A microchannel gain element is located adjacent the array of cathodes and provides a series of microchannels having a secondary electron emissive material within each of the channels. The channels correspond in number and location to the cathodes and enable multiplication of electrons emitted by the cathodes. Multiplication of the electrons enables the cathodes to be driven at a lower current of emitted electrons than normally applied, absent the microchannel, to obtain the same resulting beam. The beam exiting each of the microchannels is directed to an anode which can comprise a phosphor for use in a flat panel display.

Abstract: This invention relates to electron emitting semiconductor materials for use in dynodes, dynode devices incorporating such materials, and methods of making the dynode devices. In particular, the invention relates to emissive materials having an electron affinity that is negative and which have low resistivity. The invention also relates to electronic devices such as electron multipliers, ion detectors, and photomultiplier tubes incorporating the dynodes comprising the materials, and to methods for fabricating the electronic devices. The secondary electron emitters of the present invention comprise wide bandgap semiconductor films selected from diamond, AlN, BN, Ga.sub.1-y Al.sub.y N where 0.ltoreq.y.ltoreq.1 and (AlN).sub.x (SiC).sub.1-x where 0.2.ltoreq.x.ltoreq.1. The films are preferably single crystal or polycrystalline. The films may be continuous or patterned.

Abstract: A 360.degree. surround photon detector/electron multiplier having: i) a continuous annular inner wall formed of thin light-transmissive material defining an internal coaxial detection chamber; ii) an annular enclosed evacuated envelope integral with the inner wall; iii) a cylindrical photocathode positioned adjacent the vacuum side of the inner wall; and iv), an electron multiplier assembly housed within the envelope for multiplying photoelectrons emitted from the photocathode and operable as a plurality of adjacent, circumferentially arrayed electron multipliers, each including an output terminal. The outputs originating from various segments of the photocathode may be utilized with coincidence circuitry requiring simultaneous detection of light events in at least two different sections of the photocathode in order to eliminate spurious signals such as result from thermal electron emissions from the photocathode.

Abstract: A mesh electrode 9 is provided over an incident opening 7a of the electron multiplication portion 6. In the electron multiplication portion 6, a dynode group Dy is located downstream of a first dynode Dy1 for multiplying electrons supplied from the first dynode Dy1. The dynode group Dy is provided in the vicinity of the curvature center of the first dynode Dy1. A plate electrode 10 and a mesh electrode 9 are supplied with a potential intermediate between the potentials applied to the first dynode Dy1 and applied to the dynode group Dy. Accordingly, the electric field formed due to the potential difference between the first dynode Dy1 and the dynode group Dy is surrounded by the intermediate potentials. The electric field is therefore uniformly distributed over the region from the vicinity of the first dynode Dy1 toward the dynode group Dy.

Abstract: A photomultiplier includes a photoelectric surface for photoelectrically converting incident light and emitting electrons, and a plurality of stages of dynodes for multiplying the electrons. The photomultiplier includes a first dynode array including box-and-grid dynodes arranged in a vessel and a second dynode array including in-line dynodes arranged in the vessel. A dynode having a curved secondary electron emitting layer opposes both a secondary electron emitting layer of a last stage dynode of the first dynode array and a secondary electron emitting layer of a first-stage dynode of the second dynode array.

Abstract: There is provided a photomultiplier in which a transmittance of an incident light and a photosensitivity is high and a hysteresis characteristic is excellent. Therefore, in the present invention, a photocathode 16, dynodes 17a to 17c and an anode 18 are supported between insulating material substrates 12a and 12b provided in a glass bulb 11. A transparent conductive film 19 is formed on an inside wall surface of a light entrance portion 15. The transparent conductive film 19 electrically contacts with a pad 20 which is led through a terminal 14 to the outside. The same potential as the photocathode 12 is applied through the pad 20 to the transparent conductive film 19. The incident light directly impinges on the photocathode 16 through the glass bulb 11 and the transparent conductive film 19 at a place corresponding to the light entrance portion 15. As a result, the incident light reaches the photocathode 12 with not being interfered at all, and the transmittance of the incident light is improved.

Abstract: A photomultiplier comprising an electron multiplier for minimizing a variation in multiplication factor and noise is characterized in that insulating members are aligned on the same line to insulate a plurality of dynode plates for constituting a dynode unit from each other, thereby preventing a damage to each dynode plate. At the same time, a through hole is formed to fix the insulating member provided to each dynode plate such that a gap is provided between the major surface of the dynode plate and the surface of the insulating member, thereby preventing discharge between dynode plates, which is caused due to dust or the like deposited on the surface of the insulating member.

Abstract: An electron lens electrode for guiding photoelectrons emitted from a photocathode to an electron multiplier section is arranged between the photocathode and the light-incident portion of a sealed container, and an opening is formed at a portion of the electron lens electrode opposing the light-incident portion. Incident light reaches the photocathode through the opening without being scattered or absorbed at all. The transmittance of light incident on a photomultiplier is improved, and the output waveform is uniformed, resulting in an improved S/N ratio.

Abstract: An image intensifier tube having a conductive coating for draining away accumulated electrons that cause the image intensifier tube to lose resolution. The conductive coating is formed on the insulating surface of the image intensifier tube microchannel plate. The conductive coating is formed from the evaporation of cathode sublimation products which include barium, nickel and tungsten.

Abstract: A continuous thin film dynode includes a substrate with at least one channel having a channel wall, an isolation layer overlying the channel wall, and a thin film overlying the isolation layer. The thin film includes a current carrying portion and an electron emissive portion overlying the current carrying portion. The electron emissive portion is essentially free of a material which is silica-rich, alkali-rich, and lead-poor. The current carrying portion is essentially free of a material which is lead-rich.

Abstract: A photomultiplier for receiving incident light on a photocathode, and cascade-multiplying electrodes emitted from the photocathode by a secondary electronic effect of a plurality of dynodes, whereby the incident light is detected. The photomultiplier includes a slowing-down electrode for decelerating those of secondary electrons emitted from a dynode on the first stage to a dynode on the second stage which have a higher speed. Because of the slowing-down electrode the secondary electrons having a higher speed are selectively decelerated, whereby a transit time spread of the secondary electrons emitted from parts of the first stage-dynode to the second stage-dynode is relatively decreased.

Abstract: An X-ray detector including a photocathode arranged to receive X-ray radiation and being operative to provide in response thereto an output of electrons, and at least one electron multiplier operative at subatmospheric pressure and in response to the output of electrons from the photocathode to provide an avalanche including an increased number of electrons.

Abstract: Anti-veiling-glare glass input window for an optical device. The window has throughout a shallow surface layer over its peripheral surfaces radiation absorbent free-metal-induced color centers. A method for preparation of such a window, such is particularly suited to be used as an input window for an image intensifier, involves pre-shaping the window from clear glass and forming color centers in a shallow surface layer over at least the peripheral surfaces of the window. If the clear glass contains reduceable metal oxides the color centers are formed by subjecting at least the peripheral surfaces of the clear glass to a reducing atmosphere at a temperature high enough to cause the reducing atmospheres reducing component to diffuse into a shallow surface layer of the window and to reduce the metal oxides to free metal atoms.

Abstract: Photomultiplier tube (10) segmented into a plurality of elementary photomultipliers (11), comprising a photocathode (12), a plurality of elementary electron multipliers (13) of the "apertured sheet" type, and a plurality of focusing electrodes (14) providing the convergence of the photoelectrons emitted by the photocathode (12) towards the elementary multiplier (13). In accordance with the invention, the homologous sheets (15) of the elementary multipliers are realised on one single segmented conductor wafer (16) having a neutral zone (17) separating the active apertured zones (18) constituting the different multipliers (13). The said focusing electrodes (14) can be made from one single conductor sheet (19) in which feedthrough apertures (20) are punched through which the photoelectrons are passed towards the elementary multipliers (13).

Abstract: An optical lens has a blackened layer in its outer surface which extends to a depth sufficient to substantially eliminate reflected stray light in the lens. The blackened layer is formed by causing hydrogen under pressure to react for a predetermined time and temperature with a metal oxide of the optical material thereby leaving the metal oxide in its reduced form in the lens. Some of the oxides are reduced completely, leaving the metal in its elemental form in the layer.

Abstract: Anti-veiling-glare glass input window for an optical device. The window has throughout a shallow surface layer over its peripheral surfaces radiation absorbent free-metal-induced color centers. A method for preparation of such a window, which is particularly suited to be used as an input window for an image intensifier, involves preshaping the window from a clear glass and forming color centers in a shallow surface layer over at least the peripheral surfaces of the window. If the clear glass contains reduceable metal oxides the color centers are formed by subjecting at least the peripheral surfaces of the clear glass to a reducing atmosphere at a temperature high enough to cause the reducing atmospheres reducing component to diffuse into a shallow surface layer of the window and to reduce the metal oxides to free metal atoms.