Abstract: The present invention relates to a solar cell that can recycle a substrate, and a manufacturing method thereof. The solar cell includes: i) a plurality of nano-structures distanced from each other and extended in one direction; ii) a first conductive layer covering a first end of at least one of the plurality of nano-structures; iii) a second conductive layer distanced from the first conductive layer and covering a second end of the nano-structure; and iv) a dielectric layer disposed between the first conductive layer and the second conductive layer.

Abstract: Provided are an optical coupler, which can improve miniaturization and integration, and an active optical module comprising the same. The optical coupler comprises a hollow optical block having a through hole formed to pass an optical fiber therethrough. The hollow optical block comprises at least one incidence plane, at least one internal reflection plane, and at least one tapering region. The incidence plane is disposed at the bottom of the hollow optical block, which is parallel to the through hole, to incident-transmit light. The internal reflection plane is disposed at the top of the hollow optical block, which is opposite to the incidence plane, to reflect the light, which is received from the incidence plane, into the hollow optical block. The tapering region is configured to concentrate the light on the optical fiber in the through hole. The tapering region is formed such that the outer diameter of the hollow optical block decreases away from the internal reflection plane and the incidence plane.

Abstract: Provided is a double clad fiber device. The double clad fiber device includes a double clad fiber, a pump combiner, at least one first laser diode, and at least one second laser diode. The double clad fiber includes a core and a clad. The pump combiner provides pump light to the core and the clad through one end of the double clad fiber, respectively. The at least one first laser diode provides first pump light to the clad through the pump combiner. The at least one second laser diode provides second pump light to the core through the pump combiner.

Abstract: A light coupler emitting a high power laser with a high beam quality and a fiber laser system including the light coupler is disclosed. The light coupler includes a first optical fiber bundle comprising a plurality of first optical fibers having either a single-mode core or a few-mode core and a second optical fiber, which guides multi-mode beams and is connected to the first optical fiber bundle. The optical fiber laser system includes a light coupler having a first optical fiber bundle comprising a plurality of first optical fiber having either a single-mode core or a few-mode core and a second optical fiber, which is connected to the first optical fiber bundle, is either a single cladding optical fiber or a double cladding optical fiber, and guides multi-mode beams, and one or more gain medium optical fiber, which is connected to the light coupler and emits light.

Abstract: Provided is a method for processing received signal by applying channel status information based on OFDM. The method applies CSI to a soft-decided signal and thus can more enhance performance than a method applied to a typical decoder even without using an additional memory and the increase of a clock speed. The method appropriately perform adjustment suitable for a soft-decided and received signal in applying pre-estimated CSI to a decoder, thereby more enhancing performance and enabling adaptive application based on the change of a channel status.

Abstract: Provided is an all-optical gain-clamped fiber amplifier, comprising transmission and isolation means for periodically transmitting an optical signal or reflecting amplified spontaneous emission (ASE) back to a gain medium. The transmission and isolation means can be embodied by an optical interleaver or a number of optical fiber Bragg gratings. Accordingly, an optical signal can be amplified across the entire C-band, and an ASE reflector-based gain-clamped fiber amplifier having a wider dynamic range than conventional amplifiers can be implemented.

Abstract: A light coupler emitting a high power laser with a high beam quality and a fiber laser system including the light coupler is disclosed. The light coupler includes a first optical fiber bundle comprising a plurality of first optical fibers having either a single-mode core or a few-mode core and a second optical fiber, which guides multi-mode beams and is connected to the first optical fiber bundle. The optical fiber laser system includes a light coupler having a first optical fiber bundle comprising a plurality of first optical fiber having either a single-mode core or a few-mode core and a second optical fiber, which is connected to the first optical fiber bundle, is either a single cladding optical fiber or a double cladding optical fiber, and guides multi-mode beams, and one or more gain medium optical fiber, which is connected to the light coupler and emits light.

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

Abstract: Provided is a multi-resonant optical fiber laser system including a multi-resonator having an optical fiber containing at least one rare-earth element and an optical fiber inducing the stimulated Raman effect. The multi-resonant optical fiber laser system includes a pump light source irradiating pump light, a first resonator, which includes a first gain medium optical fiber containing at least one rare-earth element and first and second reflectors disposed to face each other across the first gain medium optical fiber and irradiates first laser radiation having a first wavelength by converting the pump light using the first gain medium optical fiber, a second resonator, which includes a second gain medium optical fiber inducing the stimulated Raman effect and third and fourth reflectors disposed to face each other across the second gain medium optical fiber and irradiates second laser radiation having a second wavelength by converting the first laser radiation using the second gain medium optical fiber.

Abstract: Provided is a fiber laser system including fiber containing dysprosium. The fiber laser system uses 1.7-?m pump light. A resonator of the fiber laser system includes a dichroic mirror, a partial reflection mirror, and/or an FBG. Therefore, the fiber laser system can provide 3-?m laser light and have high light pumping efficiency and high output power. The fiber laser system includes: fiber including dysprosium, a pump light source disposed at a side of the fiber and emitting pump light having a wavelength exciting electrons of the dysprosium from a ground energy level 6H15/2 to an energy level 6H11/2; a first reflection member, disposed between the fiber and the pump light source, transmitting the pump light, and reflecting first lasing light having a first wavelength; and a second reflection member, disposed at a side opposite to the pump light source with respect to the fiber, transmitting a portion of the first lasing light.

Abstract: In a soft decision method for demodulation of a received square QAM (Quadrature Amplitude Modulation) signal, the processing speed is improved, and the manufacturing expense is reduced, by using condition probability vector values, which are soft decision values. A condition judgment operation is employed.

Abstract: Provided are a tellurite glass composite, an optical waveguide, and an optical amplifier using the tellurite glass composite. The tellurite glass composite includes an entire composite including 25 (mol %)?TeO2?90 (mol %), 1 (mol %)?T1O3?55 (mol %) or 1 (mol %)?T2O3?40 (mol %), 0 (mol %)?ZnO?35 (mol %), 0 (mol %)?M2O?35 (mol %), and 0 (mol %)?Bi2O3?20 (mol %). Here, T1 includes a transition metal Mo, T2 includes a transition metal W, M2O includes Li2O, Na2O, or two or more of Li2O, Na2O, K2O, Rb2O, and Cs2O including metals having +1 valence electrons, and amounts of M2O and ZnO are not simultaneously “0”.

Abstract: Provided is an all-optical gain-clamped fiber amplifier, comprising transmission and isolation means for periodically transmitting an optical signal or reflecting amplified spontaneous emission (ASE) back to a gain medium. The transmission and isolation means can be embodied by an optical interleaver or a number of optical fiber Bragg gratings. Accordingly, an optical signal can be amplified across the entire C-band, and an ASE reflector-based gain-clamped fiber amplifier having a wider dynamic range than conventional amplifiers can be implemented.

Abstract: Provided is an all-optical gain-clamped fiber amplifier, comprising transmission and isolation means for periodically transmitting an optical signal or reflecting amplified spontaneous emission (ASE) back to a gain medium. The transmission and isolation means can be embodied by an optical interleaver or a number of optical fiber Bragg gratings. Accordingly, an optical signal can be amplified across the entire C-band, and an ASE reflector-based gain-clamped fiber amplifier having a wider dynamic range than conventional amplifiers can be implemented.

Abstract: Provided is a gain-clamped (GC) optical amplifier using a fiber Raman amplifier (FRA) having a Raman cavity. The FRA having a Raman cavity comprises a Raman fiber module (RFM) amplifying and outputting an input optical signal and a resonant cavity generating a Raman laser and a gain clamping laser (GC laser), wherein the resonant cavity is formed as a feedback loop between an input terminal and an output terminal of the RFM. Accordingly, a gain of an optical signal propagating along a core of RFM keeps a constant value regardless of input signal intensity by generating the GC laser for gain clamping between a wavelength band of the Raman laser and a gain band of input signals.

Abstract: Provided is a gain-clamped optical amplifier amplifying light without bandwidth loss of an incident optical signal, and the gain-clamped optical amplifier using a double-clad fiber comprises: an optical fiber including a core doped with a gain material for amplifying an optical signal, a primary clad adjacent to the outside of the core and having a lower refractive index than the core, and a secondary clad adjacent to the outside of the primary clad and having a lower refractive index than the primary clad; a light emitting element emitting a pump light for population inversion of the gain material; and a cavity unit producing laser oscillation by resonating spontaneous emission light emitted from the gain material population-inverted by the pump light.

Abstract: Provided is an optical fiber. The optical fiber includes a core and a cladding, the core containing a first element for inducing non-linear Raman phenomenon, and the cladding containing a second element which is a rare earth element, wherein when the optical fiber is pumped by two pumping light sources having different wavelengths with each other, the optical signals in the first and third band are Raman-amplified by the first element and the signals in the second band are amplified by a direct transition of the second element.

Abstract: Provided is a fiber laser system including fiber containing dysprosium. The fiber laser system uses 1.7-??m pump light. A resonator of the fiber laser system includes a dichroic mirror, a partial reflection mirror, and/or an FBG. Therefore, the fiber laser system can provide 3-?m laser light and have high light pumping efficiency and high output power. The fiber laser system includes: fiber including dysprosium, a pump light source disposed at a side of the fiber and emitting pump light having a wavelength exciting electrons of the dysprosium from a ground energy level 6H15/2 to an energy level 6H11/2; a first reflection member, disposed between the fiber and the pump light source, transmitting the pump light, and reflecting first lasing light having a first wavelength; and a second reflection member, disposed at a side opposite to the pump light source with respect to the fiber, transmitting a portion of the first lasing light.

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

Abstract: An organic-inorganic hybrid nanocomposite thin film for a high-powered and/or broadband photonic device having an organic ligand-coordinated semiconductor quantum dot layer, a photonic device having the same, and a method of fabricating the same are provided. The organic-inorganic hybrid nanocomposite thin film is composed of a stack structure comprising a polymer layer and an organic ligand-coordinated semiconductor quantum dot layer self-assembled on the polymer layer, or composed of a first composite thin film comprising a first polymer layer pattern having a first hole, and an organic ligand-coordinated first semiconductor quantum dot layer pattern filling the first hole. The organic-inorganic hybrid nanocomposite thin film may be formed by spin-coating a semiconductor quantum dot solution and a polymer solution alternately to be stacked by one layer so as to form a multi-layered organic thin film composed of a plurality of layers.