Abstract: An Outside Vapor Deposition (OVD) apparatus for making an optical fiber perform with uniform deposition of silica particles through uniform heating to the overall length of the preform includes a mandrel having a predetermined length and driven to rotate and a burner for emitting a combustion gas toward the mandrel and burning the combustion gas to make silica particles to that the silica particles are deposited on a surface of the mandrel, wherein the burner has a length corresponding to the length of the mandrel and provides uniform temperature throughout the overall length of the mandrel at the same time.

Abstract: Disclosed is an avalanche photodiode for use in super-high speed optical communication, more particularly, to a structure of an avalanche photodiode device capable of suppressing edge breakdown to increase avalanche gain factor of a light signal and to reduce a noise. The avalanche photodiode includes a wafer characterized in that the guard ring has a depth equal to that of a center part of the active region (diffused region), an edge of the active region is shallower than the center part, and the guard ring is electrically isolated from the active region. Therefore, a gain-bandwidth characteristic may be increased, and also the higher receiver sensitivity may be achieved.

Abstract: The present invention relates to an optical filter whose a sidelobe disturbing a characteristic of an optical filter by weighting an optical coupling efficiency between waveguides is controlled upon applying a selective area growth method in a wavelength selective variable semiconductor optical filter and method of fabricating the same. The present invention can control the thickness of growth layer selectively by controlling the width of the dielectric thin film mask whose the growth is not achieved in the selective area growth method, can control the distance between two waveguides of the wavelength selective variable semiconductor optical filter by applying the result on the distance control between two waveguides. Accordingly, there can be changed an optical coupling efficiency between two waveguides spatially.

Abstract: A communication among participants in on-line virtual environments is disclosed. The communication with reality among the participants is effected in the diverse virtual environments such as an on-line game, chatting, etc., by converting a text message from a specified person into a speech having its own tone during the text message communication among the participants, and by reproducing the converted message through a receiver's speaker with a sound effect added thereto. The on-line communication by speech among the participants is effected without affecting the load of the network by converting the text message received in a user terminal into the speech using a text-to-speech converter, and by reproducing the converted speech through the speaker.

Abstract: The present invention relates to a user-to-user communication system and method via a network. The communication system and method recognizes a first audio signal which is inputted from a user, converts the first audio signal into a first text data, and transmits the converted first text data, applied with a transmission code, into a counterpart terminal via the network; and receives a data applied with a transmission code from the counterpart terminal and converts the data into a second audio signal to output the same via a speaker. When one of users or garners wants to have a conversation with a counterpart gamer during a multi-user network game, communication among users participating in a multi-user on-line game can be smoothly executed in a narrow network bandwidth.

Abstract: The present invention relates to an electrical field absorbing semiconductor optical modulator, more particularly, to a high speed semiconductor optical modulator and a fabricating method thereof. The present invention includes a high speed semiconductor optical modulator, the optical modulator formed by stacking an n-type light-wave guiding layer, a light absorbing layer, a p-type light-wave guiding layer, a p-type clad layer, and a p-type ohmic contact layer on a substrate successively, the optical modulator having a ridge structure wherein the optical modulator is an electric-field absorbing type, and wherein width W3 of the light absorbing layer is less than the width W1 of the p-type ohmic contact layer. Accordingly, the present invention enables to provide high speed optical modulation of tens of giga rate of which modulating characteristics are excellent by reducing contact resistance and capacitance, which are the major problems of ruining the characteristics of an optical modulator, simultaneously.

Abstract: The present invention relates to an apparatus and method for furnishing augmented-reality graphic using panoramic image with supporting multi-user.

Abstract: The present invention relates to a method for searching a menu in a mobile communication terminal, wherein a plurality of main menus and sub menus of each main menu are simultaneously searched on a single menu screen using various navigational keys.

Abstract: The present invention relates to an optical filter for selecting a wavelength to be used in an optical communication and optical switching equipment and, more particularly, to an optical filter in order to reduce a sidelobe deteriorating its characteristics. The optical filter according to the present invention includes a plurality of pair gratings formed in a cladding layer, wherein a period of the grating pairs is constant throughout the optical filter, wherein the pair gratings are divided into two unit gratings, and wherein intervals between unit grating within pair grating are spatially different.

Abstract: A method for manufacturing the semiconductor laser device comprising the steps of sequentially forming an active layer, a photo-waveguide layer, a cladding layer, and an ohmic contact layer on an upper surface of an InP substrate; forming a first patterned dielectric layer on the ohmic contact layer; depositing a patterned photoresist on the ohmic contact layer to define a p- electrode stripe layer; forming the p- electrode stripe layer only on a part of the ohmic contact layer; performing an annealing process; etching back the layers until the photo-waveguide layer is exposed, using the first patterned dielectric layer and the p- electrode stripe layer as an etching mask, to form a ridge; depositing a second dielectric layer on the substrate formed thus; selectively removing the second dielectric layer to form a contact hole on the p- electrode stripe layer; coating a bonding pad metal layer on the second dielectric layer and in the contact hole; and coating an n- electrode metal layer on bottom surface of t

Abstract: An avalanche photodiode in which a strained superlattice structure is used as a multiplication layer, comprising: an n.sup.+ type InP substrate; an n.sup.+ type InP epitaxial layer formed on a main surface of the substrate; an N type In.sub.1-x Al.sub.x As layer formed on the epitaxial layer; an n.sup.+ type In.sub.1-x Al.sub.x As layer formed on the N type In.sub.1-x Al.sub.x As layer, the n.sup.+ type In.sub.1-x Al.sub.x As layer having a relatively high impurity concentration more than the N type In.sub.1-x Al.sub.x As layer; the multiplication layer deposited on the n.sup.+ type In.sub.1-x Al.sub.x As layer, the multiplication layer having an In.sub.0.53 Ga.sub.0.47 As/In.sub.1-x Al.sub.x As superlattice structure; first and second p.sup.+ type In.sub.1-x Al.sub.x As layers laminated sequentially on the multiplication layer; an absorbing layer formed on the second p.sup.+ type In.sub.1-x Al.sub.x As layer, the absorbing layer being made of an In.sub.0.53 Ga.sub.0.