Abstract: Provided are a tunable wavelength filter with an embedded metal temperature sensor and an external-cavity type tunable wavelength laser module. In detail, the tunable wavelength filter with an embedded metal temperature sensor and the external-cavity type tunable wavelength laser module achieve wavelength stability by forming a metal temperature sensor using a resistance change of a metal thin film according to temperature on a point on an isothermal layer having the same temperature distribution as the optical waveguide during a process for fabricating the optical waveguide with polymer to accurately measure a temperature of an optical waveguide.

Abstract: Provided is a tunable wavelength laser module including: an external cavity type light source generating broadband light; an optical waveguide; a Bragg grating formed in the optical waveguide; a heater provided above the optical waveguide in which the Bragg grating is formed and adjusting a reflection band of the Bragg grating by a thermo-optic effect; a direction change waveguide region changing direction of optical signals obtained by the adjusted reflection band of the Bragg grating, by a predetermined angle; a 45-degree reflection part transmitting some of the optical signals direction-changed by the direction change waveguide region and escaping from the optical waveguide therethrough and reflecting the others of the optical signals in a vertical upward direction thereby; and a lens making the optical signals reflected in the vertical upward direction by the 45-degree reflection part collimated light or convergent light.

Abstract: Provided are a tunable wavelength filter with an embedded metal temperature sensor and an external-cavity type tunable wavelength laser module. In detail, the tunable wavelength filter with an embedded metal temperature sensor and the external-cavity type tunable wavelength laser module achieve wavelength stability by forming a metal temperature sensor using a resistance change of a metal thin film according to temperature on a point on an isothermal layer having the same temperature distribution as the optical waveguide during a process for fabricating the optical waveguide with polymer to accurately measure a temperature of an optical waveguide.

Abstract: Provided are a rear camera system for vehicles and a parking guide system using the same, which displays the minimum width and maximum width of a parking area guideline in consideration of the dimensions of a vehicle in displaying a parking area, and displays a stop position in backing. The parking guide system includes a camera mounted on a vehicle, a display unit disposed inside the vehicle, and a parking guide control unit connected to the camera and the display unit. The parking guide control unit includes a parking logic operation unit receiving a steering angle, a speed, or a parking mode from the vehicle, a parking area guideline display unit displaying a guideline for parking guide on the basis of the result of the logic operation, and an image synthesizer synthesizing the results, displayed by the parking area guideline display unit, and an image obtained by the camera.

Abstract: Provided are a rear camera system for vehicles and a parking guide system using the same, which displays the minimum width and maximum width of a parking area guideline in consideration of the dimensions of a vehicle in displaying a parking area, and displays a stop position in backing. The parking guide system includes a camera mounted on a vehicle, a display unit disposed inside the vehicle, and a parking guide control unit connected to the camera and the display unit. The parking guide control unit includes a parking logic operation unit receiving a steering angle, a speed, or a parking mode from the vehicle, a parking area guideline display unit displaying a guideline for parking guide on the basis of the result of the logic operation, and an image synthesizer synthesizing the results, displayed by the parking area guideline display unit, and an image obtained by the camera.

Abstract: Various methods and apparatuses are described for a wavelength division multiplexing passive optical network (WDM-PON) that performs bi-directional communication. The WDM-PON may include two or more remote distribution nodes in between a central office and the most distant optical network unit. Each remote distribution node is located in a physically separate location. A first remote distribution node has two or more optical network units connected to the first remote distribution node. Each remote node separates one or more wavelength channels from a composite optical signal distributed through that remote distribution node.

Abstract: Various methods and apparatuses are described for a wavelength division multiplexing passive optical network (WDM-PON) that performs bi-directional communication. The WDM-PON may include two or more remote distribution nodes in between a central office and the most distant optical network unit. Each remote distribution node is located in a physically separate location. A first remote distribution node has two or more optical network units connected to the first remote distribution node. Each remote node separates one or more wavelength channels from a composite optical signal distributed through that remote distribution node.

Abstract: There is disclosed a mode-locked optical fiber laser stabilizing apparatus for stabilizing the length of the optical fiber laser resonator by feedbacking the optical signals to the laser resonator, in the direction where the signal reflected by the optical fiber loop mirror is detected as an error signal to minimize the signal, and method thereof.

Abstract: An apparatus for generating an optical fiber laser capable of tuning a wavelength thereof.

Abstract: A planar waveguide-type optical amplifier switch is disclosed. The switch is developed with the purpose of solving the problems that the conventional waveguide-type optical switch, which has been being used in the optical communication technique, has an optical loss and thereby requires an external optical amplifier which makes the whole devices not suitable for forming an integrated compact device. The disclosed switch performs switching function from the refractive index change in the optical waveguides induced by electrical or optical controls as well as amplifying function of the optical signal, when it passes through the waveguides, from use of optical waveguides formed of a fluorescence emitting material with an optical pumping and a wavelength division multiplexing (WDM) optical waveguide-type coupler.

Abstract: The present invention relates to a complex rare-earths doped optical waveguide. In particular, the complex rare-earths doped optical waveguide in accordance with an embodiment of the present invention is for modifying emission spectrum of erbium that is able to obtain gain from shorter wavelength than 1530 nm. A complex rare-earths doped optical wavelength is provided. The complex rare-earths doped optical waveguide in accordence with an embodiment of the present invention includes clad and core. The core is doped with erbium (Er) ion. The internal or surface of the core is doped with at least one complex rare-earth ions. The internal and the surface of the core is distanced by certain length from center of the core.

Abstract: An optical fiber cascaded Raman laser scheme is provided. An optical fiber cascaded Raman laser scheme in accordance with an embodiment of the present invention includes a pump light source, an optical fiber, a wavelength division multiplexing optical fiber combiner, another wavelength division multiplexing optical fiber combiner, a short period optical fiber bragg grating, a long period bragg grating, first means, and second means. The pump light source generates pump light. The optical fiber causes Raman scattering regarding the optical pump light as nonlinear material. The wavelength division multiplexing optical fiber combiner forms intra cavity regarding light of second order stoke frequency shifted wavelength. The light is stoke frequency shifted by Raman scattering of the optical fiber. The another wavelength division multiplexing optical fiber combiner forms intra cavity regarding light of first and third order stoke frequency shifted wavelength.

Abstract: Provided are complex optical material that trivalent ytterbium ion is codoped into single crystalline, poly crystalline or amorphous material containing tetravalent chromium ion or trivalent vanadium ion as an active medium, and a using method of the material. In application of the material to solid-state lasers, optical fiber amplifiers and the likes, when excitation occurs in the 980 nm wavelength band in which absorption strongly occurs at the ytterbium ion with avoiding the wavelength range of 600˜800 nm in which the excited-state absorption occurs at the chromium ion, the energy is transferred from the ytterbium ion to the chromium ion to emit fluorescence in the range of 1200˜1600 nm wavelength. Accordingly, the present invention is to solve the problem of the excitation efficiency decrease of the tetravalent chromium ion due to the excited-state absorption and to enhance the fluorescence emission intensity.

Abstract: The present invention relates to an optical fiber amplifier incorporating therein a wavelength division multiplexer and a plurality of diffraction grating pairs for generating a number of optical signals with a pumping light of one wavelength, each optical signal having a different wavelength. The optical device includes a first optical means for guiding the first pumping light and the optical signals, a second optical means for generating a second pumping light with the first pumping light and generating the plurality optical signals with the second pumping light, and an optical coupler for introducing the first pumping light into the second optical means and outputting the optical signals.

Abstract: A mode-locked fiber laser and a fiber amplifier using a single pump laser, the fiber laser using a pump source to generate soliton optical short pulse and the fiber amplifier amplifying the optical short pulse. The mode-locked fiber laser and fiber amplifier use a single pump laser in accordance with an embodiment of the present invention that includes a tunable directional coupler, a mode-locked fiber laser, and an optical amplifier. The tunable directional coupler is connected to the pump source. The mode-locked fiber laser receives the pump output of the pump source and generates a soliton optical pulse. The mode-locked fiber laser is connected to an output port of the tunable directional coupler. The optical amplifier receives the pump output of the pump source, receives the soliton optical pulse generated by the mode-locked fiber laser, and amplifies the soliton optical pulse. The optical amplifier is connected to the other output port of the tunable directional coupler.

Abstract: An apparatus for measurement of an optical pulse shape intended to measure the temporal waveform of an ultrashort single optical pulse is disclosed. The present invention comprises a linearly chirped supercontinuum light source that is synchronized with an optical pulse to be measured; a nonlinear optical interferometer to transform the temporal waveform of an incident optical pulse into a spectrum using an incident light from said supercontinuum light source; and an optical spectrum analyzer to measure the wavelength of the light passing through the nonlinear interferometer so that it can measure the temporal waveform of a single optical pulse. The present invention employs the method that transforms the temporal waveform of an incident optical pulse into a spectrum and measures the wavelength using a linearly chirped supercontinuum light source, a nonlinear optical interferometer, and an optical spectrum analyzer.

Abstract: The present invention provides a tunable optical filtering system using fiber-optic polarimetric interferometer. The tunable optical filtering system using fiber-optic polarimetric interferometer in accordance with the present invention comprises a stabilization light source, a first polarization beam splitter, a first optical fiber node, a number of polarization maintaining optical fibers, a phase modulator, a stabilization electronics, a second optical fiber node, a second polarization beam splitter, and two wavelength division optical multiplexers. The stabilization light source supplies stabilization light. The first polarization beam splitter polarizes the stabilization light and the input light to be filtered and generates polarized light. The first optical fiber node connects the output of the first polarization beam splitter with polarization maintaining fibers with the angle of 45 degree between their birefringent axes and splits the polarized light.

Abstract: The present invention provides a demultiplexer for generating a constant four-wave-mixing beam without regard to an input polarization state using a dispersion-shifted fiber that is a nonlinear material with high refractive index. A number of parts in conventional demultiplexer implementations, which are sensitive to input polarization state has been replaced with optical fibers of high polarization mode dispersion.

Abstract: An optical fiber Mach-Zehnder interferometer optical filter is disclosed.

Abstract: The present invention discloses an all-optical wavelength converter using a semiconductor optical amplifier and a polarization interferometer. The all-optical wavelength converter using a semiconductor optical amplifier and a polarization interferometer including a wavelength converter which modulates a probe light into a inverting waveform to a signal light and outputs the modulated light by using cross gain modulation, a phenomenon that occurs while the signal light and the probe light pass together through an optical splitter/combiner, a semiconductor optical amplifier and a filter at the same time, a polarization interferometer which makes the probe light outputted from the wavelength converter and having the inverting waveform to the signal light undergo a double-refraction so that a predetermined time split occurs on it and provides a non-inverting wavelength conversion and suppresses the slow XGM components in the converted outputs due to the slow carrier recombination time.