It is an object of the present invention to provide a probe that may correspond to various styles of measurement when used in microscopes and that is also applicable to recording devices and an optical head using the same, as well as to provide a method for manufacturing such a probe in a simple and costless manner; for achieving such objects, the method for manufacturing a multiple optical path array type probe according to the present invention is arranged in that in a light guiding material including a substrate that functions as a clad and a light guiding path formed of a component that functions as a core for guiding light or as a waveguide, the light guiding material includes a plurality of light guiding paths aligned to be parallel to each other within the substrate that functions as a clad, and tip end portions of the light guiding paths are sharpened through chemical etching of an end surface that is orthogonal to the plurality of light guiding paths.

The faceplate of a light detector tube is provided with an internal photocathode having wedge-shaped projections and external lenses to concentrate the light from a source onto the projecting photosensitive surface areas. An accelerating grid having a corresponding configuration is spaced closely to the photocathode to increase the emission of electrons from the photosensitive surface. A potential source establishes an electric field between the photocathode and an anode, with the anode collecting the electrons.

A photo electric conversion tube in which a translucent photocathode surface is provided inside of an incident light window. The incident light window is made of glass plate and an optical fiber plate bonded to at least part of the glass plate or just the optical fiber plate on the photocathode surface. The optical fiber plate contains fibers which are inclined at an angle to the photocathode surface.

A photocathode arrangement comprises a body of semiconductor material, such as gallium arsenide which is bonded to a fiber optic face plate. A thin anti-reflection coating of silicon nitride is positioned between the body and the plate and forms an integral part of the bond. The properties of the glasses from which the fiber optic face plate is made are carefully chosen to minimize crystal dislocations which can be introduced into the body of gallium arsenide when it is bonded to the face plate. Such crystal dislocations can seriously impair the performance of the photocathode. It has been found that it is advantageous to use a glass having an annealing temperature of about 575.degree. C. or less. Because of high temperature processing steps, its softening temperature must be about 680.degree. C. or greater. The photocathode arrangement so formed is intended to constitute the input port of an image intensifier.

A fiber optics device of this invention includes first and second assemblies. The first assembly is obtained by integrating a plurality of optical fibers by bundling, and has first and second end faces formed obliquely to the optical axis of the optical fibers contained in it. The second end face has small recesses and projections to scatter light emerging from it. The second assembly is obtained by integrating a plurality of optical fibers by bundling, and has first and second end faces substantially intersecting perpendicularly to the optical axis of the optical fibers contained in it. The first end face of the second assembly is bonded to the second end face of the first assembly. As a result, an optical loss occurring at the bonding portion between the assemblies can be decreased.