Abstract: Provided is an apparatus for manufacturing an optical fiber Bragg grating.

Abstract: Provided is a gain-clamped fiber amplifier for amplifying the magnitude of an input optical signal in an optical communication system. The gain-clamped fiber amplifier includes a first amplifier for amplifying a predetermined optical signal and a second amplifier for compensating for a noise figure characteristic of the first amplifier and for separating remaining pumping light whose intensity changes in accordance with an optical signal. Therefore, it is possible to improve the noise figure and dynamic range characteristics and the performance of the amplifier.

Abstract: Provided is a gain-clamped fiber amplifier for amplifying the magnitude of an input optical signal in an optical communication system. The gain-clamped fiber amplifier includes a first amplifier for amplifying a predetermined optical signal and a second amplifier for compensating for a noise figure characteristic of the first amplifier and for separating remaining pumping light whose intensity changes in accordance with an optical signal. Therefore, it is possible to improve the noise figure and dynamic range characteristics and the performance of the amplifier.

Abstract: The present invention is a thulium doped silicate glass having an excellent fluorescent emission in the 1.4 ?m band, and the usage thereof. The silicate glass of this invention includes: 65˜95 mol % SiO2; 0.5˜30 mol % bivalent metal oxide consisting of one or more material selected from ZnO, BaO, SrO and PbO; and 1˜15 mol % of SnO2 or TiO2, wherein 3˜30 mol % oxygen of the glass composition are replaced with fluorine, and 0.01˜1 mol % of thulium ions are doped, and the fluorescence lifetime of the 3H4 level of the Tm3+ is more than 50 ?s. The silicate glass can be easily formed into a waveguide, such as optical fiber, and it has an excellent ability to splice with the optical fiber for transmission. They have excellent chemical durability and the characteristic of 1.4 ?m band fluorescent emission by suppressing the non-radiative transition through multi-phonon relaxation. Thus they have long fluorescence lifetime of the 3H4 of Tm3+.

Abstract: The present invention relates to a main wavelength band of a pump light source capable of improving the pump efficiency while using 1.6 ?m fluorescence emitted from Ho3+:5I5?5I7 transition as an optical amplifier, and an assistant pump wavelength band capable of accomplishing population inversion between 5I5 level and 5I7 level to improve the signal gain characteristics of such amplifier. The optical amplifier using optical materials to which holmium or holmium and terbium, holmium and europium, holmium and neodymium or holmium and dysprosium, etc. are doped can be pumped using a light source that emits light of 11,200˜11,500 cm?1 or a light source that emits light of 6,000˜6,500 cm?1.

Abstract: The present invention relates to a main wavelength band of a pump light source capable of improving the pump efficiency while using 1.6 &mgr;m fluorescence emitted from Ho3+:5I5→5I7 transition as an optical amplifier, and an assistant pump wavelength band capable of accomplishing population inversion between 5I5 level and 5I7 level to improve the signal gain characteristics of such amplifier. The optical amplifier using optical materials to which holmium or holmium and terbium, holmium and europium, holmium and neodymium or holmium and dysprosium, etc. are doped can be pumped using a light source that emits light of 11,200˜11,500 cm−1 or a light source that emits light of 6,000˜6,500 cm−1.

Abstract: The present invention is a thulium doped silicate glass having an excellent fluorescent emission in the 1.4 &mgr;m band, and the usage thereof. The silicate glass of this invention includes: 65˜95 mol % SiO2; 0.5˜30 mol % bivalent metal oxide consisting of one or more material selected from ZnO, BaO, SrO and PbO; and 1˜15 mol % of SnO2 or TiO2, wherein 3˜30 mol % oxygen of the glass composition are replaced with fluorine, and 0.01˜1 mol % of thulium ions are doped, and the fluorescence lifetime of the 3H4 level of the Tm3+ is more than 50 &mgr;s. The silicate glass can be easily formed into a waveguide, such as optical fiber, and it has an excellent ability to splice with the optical fiber for transmission. They have excellent chemical durability and the characteristic of 1.4 &mgr;m band fluorescent emission by suppressing the non-radiative transition through multi-phonon relaxation. Thus they have long fluorescence lifetime of the 3H4 of Tm3+.

Abstract: An optical amplifier of the present invention includes a pump source for generating a pumping light, a wavelength division multiplexing (WDM) coupler for multiplexing an inputted optical signal and the pumping light and an optical fiber including a core and a clad, wherein the core has holmium ions less than 0.5 mole % and the clad has ions selected from the group consisting of transition metal ions, rare earth ions and a combination thereof. In addition, the phonon energy of a host material is less than 600 cm−1 and an absorption band at short-wavelength side is shorter than 530 nm.

Abstract: An optical amplifier of the present invention includes a pump source for generating a pumping light, a wavelength division multiplexing (WDM) coupler for multiplexing an inputted optical signal and the pumping light and an optical fiber including a core and a clad, wherein the core has holmium ions less than 0.5 mole % and the clad has ions selected from the group consisting of transition metal ions, rare earth ions and a combination thereof. In addition, the phonon energy of a host material is less than 600 cm−1 and an absorption band at short-wavelength side is shorter than 530 nm.