摘要:
An optical fiber preform includes a core made from a fluoride glass which is doped with a rare earth, and a cladding surrounding the core. The cladding is made from one of an oxide glass and a fluoroxide glass. The core has a characteristic of amplification at 1.3 .mu.m-band. The cladding does not have absorption at 1.3 .mu.m-band. The preform is useful as a material for a fiber optical amplifier in optical communication systems.
摘要:
A method of forming a fiber glass preform includes the steps of: (a) pouring a cladding glass into a mold; (b) pouring a core glass on a flat horizontal upper surface of the cladding glass so as to form a united glass body having the core glass and the cladding glass under a condition that viscosity of the cladding glass and viscosity of the core glass are adjusted to certain predetermined values respectively so that the core glass is separated from and placed on the cladding glass; (c) cooling the united glass body to solidify the same so that the cladding glass is deformed by contraction thereof so as to produce a depression at a top middle portion thereof and that the core glass is deformed so as to form a projected portion thereof to fill the depression therewith; (d) separating the united glass body into an upper portion and a lower portion comprising the projected portion of the core glass; and (e) extruding the lower portion of the united glass body so as to form the fiber glass preform.
摘要:
An upconversion laser material includes a micro-sphere which is doped with an ion of a rare earth element and made of one selected from the group consisting of crystals and glasses. Thus, the micro-sphere achieves the light confinement therein and serves as a resonator. Therefore, the Q-value of the resonator becomes large. With this, it is possible to obtain the upconversion laser oscillation at room temperature.
摘要:
Pulsed light is irradiated to an amorphous base material, to produce therein one or more single crystals or polycrystals having nonlinear characteristic advantageous for light communication and laser technique. An external field such as electric field or magnetic field may be applied to the amorphous material, or a seed crystal or crystalline substrate may be used to promote crystallization from a contact interface between the amorphous material and the seed crystal or crystalline substrate.
摘要:
A glass includes (a) a matrix containing a compound of at least one nonmetallic element; and (b) a particle selectively formed in the matrix. This particle is made of the at least one nonmetallic element. A process for producing such glass includes (a) providing a blank glass containing a compound of at least one nonmetallic element; (b) condensing a pulsed laser beam to a focal point in the blank glass such that a particle is selectively formed in the blank glass at a position corresponding to the focal point, the particle being made of the at least one nonmetallic element dissociated from the compound; and (c) moving the focal point in the blank glass to produce a pattern of the particle. The glass is suitable for optical functional elements.
摘要:
Pulsed light is irradiated to an amorphous base material, to produce therein one or more single crystals or polycrystals having nonlinear characteristic advantageous for light communication and laser technique. An external field such as electric field or magnetic field may be applied to the amorphous material, or a seed crystal or crystalline substrate may be used to promote crystallization from a contact interface between the amorphous material and the seed crystal or crystalline substrate.
摘要:
The invention relates to a 1.4-1.52 &mgr;m-band optical amplifier. This optical amplifier includes (a) a first pumping source for a first pumping light in a wavelength range defined as being not less than 0.65 &mgr;m and being less than 0.77 &mgr;m; (b) a second pumping source for a second pumping light in a wavelength range of from 1.0 to 1.2 &mgr;m; (c) an optical multiplexer for combining said first and second pumping lights with a signal light, to produce a combined light; and (d) a light amplifying optical waveguide for amplifying said signal light by receiving said combined light, said optical waveguide comprising a core doped with Tm. The optical amplifier is highly efficient.
摘要:
The invention relates to an optical waveguide having a core made of one member selected from halide glasses, chalcogenide glasses and oxyhalide glasses. This one member is doped with both of erbium and cerium. The invention further relates to a 1.5 &mgr;m-band optical amplifier having the optical waveguide for amplifying the light. Due to the doping of both erbium and cerium, it becomes possible to provide a highly efficient optical amplifier having low noise and wide band. With this, it becomes possible to construct an optical communication network having high credibility, high capacity and high speed.
摘要:
Crystallization of a fluoride glass article is suppressed by treating the surface(s) of the fluoride glass article with a solution of a fluorine-containing alkali metal compound or a fluorine-containing ammonium compound such as, e.g., LiPF.sub.6, NaBF.sub.4 or NH.sub.4 BF.sub.4, in a nonaqueous solvent such as, e.g., ethanol, N,N-dimethylformamide or acetonitrile. The treatment can be made at room temperature.
摘要:
This invention is related to a discernment card which is resistant to bending and high heat, and capable of preventing unauthorized copying of recorded identity information leakage of personal information and deletion of identity information, and to a discernment card business system for preventing unauthorized use of identity information. The discernment card (1) comprises a card main body (10) integrally formed by a high strength alloy and at least one identity information recording portion (20) comprising specific identity information inscribed on the card main body, wherein plural cells (30) are inscribed at predetermined positions of identity information recording portion of the card main body and specific identity information of the identity information recording portion is specified by one or more of inscribed depth, inscribed width and inscribed shape of the cells. The discernment card can be used in the discernment card business system to accomplish a transaction such as an Automated-Teller-Machine (ATM) or a social security-related transaction.