Abstract: An infrared transmitting chalcogenide glass lens having precision optical surfaces of different curvature radii is molded. A pair of molds having different curvature radiuses from each other, and a bushing which controls the thickness of the lens is provided. A block of chalcogenide glass is placed within the cavity. The upper mold, the lower mold and the block of glass are heated with the mold having a smaller curvature radius being at a higher temperature than the other mold. The glass is then pressed, cooled, and the resulting lens is removed from the mold assembly.

Abstract: An infrared-transmissive lens formed by using glass including germanium and selenium or germanium and sulfur as main components and a human body detecting device including the lens and a pyroelectric infrared sensor are disclosed. With this configuration, glass having excellent transmissivity of infrared rays, no poisonous characteristic and difficulty to be crystallized is obtained and the glass is subjected to thermal pressing work to form a lens. The lens and a pyroelectric infrared sensor are combined to obtain a scanning type human body detecting sensor device. Further, the scanning type human body detecting sensor device can be used to detect a plurality of human bodies simultaneously.

Abstract: A method for producing an optical fiber which comprises steps of:spinning an optical fiber from a molten preform for an optical fiber,applying a UV-curable resin to the surface of the spun optical fiber, andirradiating UV light through a layer of a material for absorbing UV light and a layer of a gas for preventing uncuring of the UV-curable resin to cure the UV-curable resin, by which the UV curable resin is homogeneously cured along its length.