Abstract: A processing method of a silica glass fiber, which is applicable to a long fiber, to improve its UV resistance by UV irradiation and heat treatment. Initially, a heating furnace 1 is positioned such that the left end of the silica glass fiber is within the heating furnace 1. Then, the heating furnace 1 is moved toward the right, while UV is irradiated with a UV source to the left end surface of the silica glass fiber. Since the silica glass becomes transparent due to removal of structural defects that have been caused by the UV irradiation, the UV travels further forward and causes other structural defects there. When the heating furnace 1 is moved there, the structural defects are removed and the silica glass fiber becomes transparent. By repeating these steps, the fiber is processed throughout length. Thus, mass production becomes possible and an improvement of productivity and lower costs can be achieved.

Abstract: Voltage is applied between electrodes (14a, 14b) under UV irradiation to perform a UV excitation poling, thereby producing microcrystal particles at a core unit (10a). Accordingly, second-order optical nonlinearity is developed at the core unit (10a) of an optical fiber (10). Under a high-temperature condition, a second-order optical nonlinearity can be imparted by a comparatively low-voltage UV excitation poling when a second-order optical nonlinearity decreases.

Abstract: A Ge-added SiO2 thin film (12) is formed on a glass substrate (10), and metal film (14) is formed thereon (S11 to S13). By etching the metal film (14), a pair of electrodes (14a, 14b) mutually opposed at a predetermined interval is formed(S14). An insulating thin film (16) is formed on the insulating film (12) and the electrodes (14a, 14b) (S15). While applying ultraviolet radiation, a high voltage is applied between the electrodes (14a, 14b) to perform ultraviolet excitement polling to impart an optical nonlinearity to a channel region (18)(S16). By controlling the voltage application to the channel region (18) having the optical nonlinearity, the light transmitted through the channel region (18) is controlled. Thus, an optical nonlinear waveguide for propagating single mode light is formed on a glass substrate.

Abstract: A metal film (12) is formed on the surface of a glass substrate (10) and etched to form a pair of electrodes (12a and 12b) which face each other with a certain gap therebetween (S11˜S13). The substrate (10) is doped with germanium, etc, by using the electrodes (12a and 12b) as a mask to form a core part (14, S14). Then a high voltage is applied between the electrodes while ultraviolet radiation is applied and the core part (14) is subjected to ultraviolet-driven boring to give the optical nonlinearity to the core part (14, S15). The voltage application to the core part (14) having the optical nonlinearity is controlled to control a light transmitting through the core part (14).

Abstract: Voltage is applied between electrodes (14a, 14b) under UV irradiation to perform a UV excitation poling, thereby producing microcrystal particles at a core unit (10a). Accordingly, second-order optical nonlinearity is developed at the core unit (10a) of an optical fiber (10). Under a high-temperature condition, a second-order optical nonlinearity can be imparted by a comparatively low-voltage UV excitation poling when a second-order optical nonlinearity decreases.

Abstract: A processing method of a silica glass fiber, which is applicable to a long fiber, to improve its UV resistance by UV irradiation and heat treatment. Initially, a heating furnace 1 is positioned such that the left end of the silica glass fiber is within the heating furnace 1. Then, the heating furnace 1 is moved toward the right, while UV is irradiated with a UV source to the left end surface of the silica glass fiber. Since the silica glass becomes transparent due to removal of structural defects that have been caused by the UV irradiation, the UV travels further forward and causes other structural defects there. When the heating furnace 1 is moved there, the structural defects are removed and the silica glass fiber becomes transparent. By repeating these steps, the fiber is processed throughout length. Thus, mass production becomes possible and an improvement of productivity and lower costs can be achieved.

Abstract: A method of manufacturing an optical fiber using silica glass having properties changed by UV irradiation and heat treatment, which method facilitating efficient mass production of long optical fibers. A base material of silica glass is heated in a fiber spinning heating furnace, and a silica glass fiber is drawn out of the forward end of the heating furnace to be spun up. In a UV irradiation zone, UV is irradiated to the spun silica glass fiber. As a result, multiple structural defects are caused in the silica glass fiber. When the structural defects are removed by heat treatment, the average bond angle of Si—O—Si network in the silica glass increases compared with that before heat treatment, and structural relaxation proceeds to provide a structurally stable glass, in which generation of defects due to further UV irradiation is hindered. Thus, a silica glass fiber having high UV resistance is obtained.

Abstract: A core section (10a) is formed in an optical fiber (10) made of a glass material and, electrodes (14a and 14b) are inserted into the clad section (10b) of the fiber (10). When the core section (10a) is irradiated with ultraviolet rays in prescribed intensity patterns while a high voltage is applied to the electrodes (14a and 14b), a grating section (16) in which non linear areas (16a) and normal areas (16b) are alternately formed is formed in the section (10a). The characteristics of the grating section (16) can be changed by utilizing an electrooptic effect by impressing a prescribed electric field upon the section (16) through the electrodes (14a and 14b). A grating element constituted in such a way can be utilized as an optical functional element, such as the wavelength switch, because the Bragg wavelength of the element changes when a voltage is applied.

Abstract: This ultralow-loss glass is characterized in that high purity silica glass contains 1 to 500 wt.ppm of at least one network modifying oxide. It is assumed that the network modifying oxide appropriately loosens the tetrahedral network structure of silica and hence Rayleigh scattering is decreased. Examples of the network modifying oxide include Na.sub.2 O, K.sub.2 O, Li.sub.2 O, MgO, CaO, and PbO. Since Rayleigh scattering losses are minimal in comparison with those of high purity silica glass, this impurity-added silica glass is excellent as a base material of a glass fiber for a long-distance transmission.

Abstract: The contact lens of the present invention is produced by a process comprising a step of irradiating a transparent polymeric material with charged particles and a step of applying an etching treatment to the resulting material to form microfine holes therein along the tracks of the charged particles.