Abstract: An optical fiber for maximizing residual mechanical stress and an optical fiber grating fabricating method using the optical fiber are provided. The optical fiber includes a core formed of silica, for propagating light, and a cladding formed of boron-doped silica, surrounding the core. Alternatively, the optical fiber includes a core formed of phosphorous-doped silica and a cladding formed of silica, surrounding the core.

Abstract: An optical fiber for maximizing residual mechanical stress and an optical fiber grating fabricating method using the optical fiber are provided. The optical fiber includes a core formed of silica, for propagating light, and a cladding formed of boron-doped silica, surrounding the core. Alternatively, the optical fiber includes a core formed of phosphorous-doped silica and a cladding formed of silica, surrounding the core.

Abstract: An optical fiber for maximizing residual mechanical stress and an optical fiber grating fabricating method using the optical fiber are provided. The optical fiber includes a core formed of silica, for propagating light, and a cladding formed of boron-doped silica, surrounding the core. Alternatively, the optical fiber includes a core formed of phosphorous-doped silica and a cladding formed of silica, surrounding the core.

Abstract: A low-loss, high-efficiency optical demultiplexer has a plurality of first optical devices and a plurality of second optical devices serially connected among the first optical devices. Each first optical device has first, second and third ports, receives an input optical signal via the first port, directs the input optical signal to the second port, and directs an optical signal returning via the second port only to the third port. Each second optical device has fourth and fifth ports connected between the first port of a corresponding first optical device and the second port of another corresponding first optical device, reflects only an optical signal having a corresponding wavelength component in the optical signal received via the fourth port, and passes an optical signal having the other wavelength components to the fifth port. In the second optical devices, different wavelength components of an optical signal received via the fourth port are reflected.

Abstract: An erbium-doped optical fiber (EDF) and a fabricating method thereof The erbium-doped optical fiber has a core formed by substantially doping silica with erbium and having gratings formed therein at a predetermined period, for propagating light therethrough, and a cladding surrounding the core and having a lower refractive index than the core. Since the erbium-doped optical fiber acts as a gain flattening filter, an erbium-doped fiber amplifier formed out of the erbium-doped optical fiber obviates the need of splicing an erbium-doped optical fiber with a gain flattening filter.

Abstract: There is provided a device and method for forming optical fiber anti-symmetric long period gratings by microbending. In the optical fiber grating forming device, a laser system emits a CO2 laser beam, a lens focuses the CO2 laser beam on an optical fiber in a predetermined width, an optical fiber support fixes both ends of the optical fiber and imparts tensile strain to the optical fiber, and a controller controls the intensity of the CO2 laser beam, the focusing distance of the lens, and the tensile force applied by the optical fiber support.

Abstract: An apparatus and method of fabricating long-period fiber grating is provided. The apparatus includes a fiber, a string, one end of which is fixed, that is located over the fiber and vibrates at a predetermined vibration frequency, a vibrating portion, which vibrates the string at the vibration frequency, to which the other end of the string is connected, and a laser source for illuminating a laser on the string and the fiber, wherein the laser is periodically transmitted by the fiber due to the vibration of the string, and thus the refractive index of the fiber is changed. The long-period fiber grating is easily formed by locating the string, which vibrates at a predetermined vibration frequency, over the fiber and illuminating a laser to the resultant structure.

Abstract: An apparatus and method used in manufacturing a long period grating filter are provided. The apparatus used in manufacturing a long period grating filter includes an upper body including a plurality of teeth spaced from each other by a predetermined distance and a lower body having teeth spaced from each other by the same distance as the teeth of the upper body and a plurality of grooves in a direction perpendicular to the teeth in which an optical fiber is loaded, wherein the upper and lower bodies are engaged with each other, and a plurality of grooves are formed in the loaded optical fiber by abrading the loaded optical fiber by moving the upper body in a direction parallel to the teeth. According to the present invention, an excimer laser, various other expensive equipment, and an optical fiber sensitive to ultraviolet rays are not required for manufacturing the long period grating filter. Accordingly, complicated hydrogen processing is not necessary.

Abstract: An amplitude mask used in a long period grating filter manufacturing apparatus includes a metal substrate having a periodic transmission area having a period for selectively transmitting light and a non-transmission area through which light does not pass; and a piezo-electric transducer located on the non-transmission area of the metal substrate for changing the period of the periodic transmission area. The periodic transmission area is located in the middle of the metal substrate and the piezo-electric transducer is located on opposite sides of the periodic transmission area. Piezo-electric transducers may be located on the non-transmission area to vary the period of the periodic transmission area.