Abstract: The present invention relates to a multi-layer optical planar waveguide which is vertically coupled using multimode-interference couplers and to the method of manufacturing the same. The purpose of this invention is to increase the degree of integration on the multi-layer optical planar waveguide by applying the concept of via holes of the multi-layer printed circuit board (MLPCB) used in electronic circuits to the optical waveguide devices. According to the present invention, particularly, a multimode interference coupler of a stepped structure has the higher coupling ratio at relatively short length of interference than the usual multimode interference coupler. The present invention can implement a multimode interference coupler at a specialized spot while reducing evanescent field interference between the upper and lower optical waveguides out of the spot by separating the layers enough.

Abstract: Organic dye molecular materials prepared by coupling existing organic chromophore molecules to benzene or carbazole derivatives and nonlinear optical polymeric compounds having polyimide repeating units coupled with the organic dye molecular material are provided. The organic dye molecular material coupled to a polymer main chain in the preparation of the nonlinear optical polymeric compound has one of the following formula: where X1 is carbon, oxygen, sulfur, nitrogen, ester (CO2), or amide (CONR1), where R1 is an alky or phenyl group having 1 to 6 carbon atoms, D is an organic chromophore molecule, and n is an integer from 1 to 10.

Abstract: The present invention relates to the polarization-independent optical polymeric intensity modulator independent of input signal using polymers with electro-optical property. To use the electro-optical property for electro-optical polymer, polymers must be poled by applying high voltage to the waveguide. The size of phase modulation caused by such an poling varies from the biggest value at polarization parallel to the poling to the smallest value at polarization perpendicular to the poling. Therefore, the performance of the electro-optical polymeric intensity modulator depends on the polarization state of input light. The present invention provides the polarization-independent optical polymeric intensity modulator capable of modulating the optical intensity without regard to the polarization of the input signal by making the polarizing directions of two optical paths of M-Z interferometer perpendicular each other.

Abstract: Organic dye molecular materials prepared by coupling existing organic chromophore molecules to benzene or carbazole derivatives and nonlinear optical polymer compounds having polyimide repeating units coupled with the organic dye molecular material are provided.

Abstract: Organic dye molecular materials prepared by coupling existing organic chromophore molecules to benzene or carbazole derivatives and nonlinear optical polymeric compounds having polyimide repeating units coupled with the organic dye molecular material are provided.

Abstract: The present invention relates to an optical waveguide and method of manufacturing the same. An optical waveguide is constructed using a clad layer having a refractive index almost same to a core layer in an input/output region coupled to an optical fiber. The optical waveguide is constructed using the clad layer having a large difference in the refractive index with the core layer in an active region having an electrode. Therefore, a driving voltage, a driving power and a coupling loss are reduced to improve a characteristic of the optical waveguide device.

Abstract: A host-guest polymer system including a polymer with an isoimide group and an organic chromophore and capable of converting into a side-chain polymer system, a side-chain nonlinear optical polymer derived from the host-guest polymer system, and a method for synthesizing the side-chain nonlinear optical polymer are provided.

Abstract: In a wavelength converter using a nonlinear polymeric waveguide, a wavelength variable wavelength converter having a nonlinear polymeric waveguide in which insertion losses are minimized and wavelength conversion efficiencies are improved, and an optical device using the wavelength converter are provided. The wavelength converter for converting the wavelength of inputted light includes a semiconductor substrate, a first electrode formed on the semiconductor substrate, a lower cladding layer formed on the first electrode, a core layer formed on the lower cladding layer and formed of nonlinear polymer by which the wavelength of light is substantially converted by the inputted light, an upper cladding layer formed on the core layer, and a second electrode formed on the upper cladding layer, which tunes center wavelengths of the conversion by adjusting the refractive index of the core layer.

Abstract: A wavelength selector to be used in WDM networks is provided. The wavelength selector is composed of a circulator, an arrayed waveguide grating (AWG), which is used for wavelength demultiplexing and multiplexing part, and an electro-optical (EO) switching part. The input light after the circulator is demultiplexed through the AWG part and each channel of the demultiplexed lights is modulated and reflected through the EO switching part which is formed as Michelson type interferometer with mirror parts returning the light to the AWG. The modulated and reflected light is multiplexed through the AWG and the direction is changed to the output through the circulator.

Abstract: The present invention relates to a multi-layer optical planar waveguide which is vertically coupled using multimode-interference couplers and to the method of manufacturing the same. The purpose of this invention is to increase the degree of integration on the multi-layer optical planar waveguide by applying the concept of via holes of the multi-layer printed circuit board (MLPCB) used in electronic circuits to the optical waveguide devices. According to the present invention, particularly, a multimode interference coupler of a stepped structure has the higher coupling ratio at relatively short length of interference than the usual multimode interference coupler. The present invention can implement a multimode interference coupler at a specialized spot while reducing evanescent field interference between the upper and lower optical waveguides out of the spot by separating the layers enough.

Abstract: A tunable Fabry-Perot filter is provided with two optical fibers each being coated with a high-reflective thin film at its one end, a silicon block for aligning the two optical fibers with each other having a pair of V-shaped grooves formed at both ends thereof, respectively, a resonant cavity medium of silicon or polymeric material having a high coefficient of thermo-optic effect, and a thermal electrode for applying heat to the resonant cavity medium.

Abstract: Organic dye molecular materials prepared by coupling existing organic chromophore molecules to benzene or carbazole derivatives and nonlinear optical polymeric compounds having polyimide repeating units coupled with the organic dye molecular material are provided.

Abstract: The present invention makes light input/output portions being a coupling portion with an optical fiber and a Y-branch using a rib waveguide, and a bending portion using a channel waveguide, wherein the rib waveguide and the channel waveguide is connected by a tapered waveguide. So that the present invention can improve the crosstalk, loss and operating voltage characteristics.

Abstract: Disclosed is a thermo-optic tunable attenuator, which comprises a single mode channel optical waveguide, an optical waveguide of a Mach-Zehnder interferometer structure coupled with the single mode channel optical waveguide, the optical waveguide including two symmetric Y-branches, and two metal heating wires for applying power to one side of each of the two symmetric Y-branches, wherein the two metal heating wires are in a facing relationship with each other, wherein a refractive index of the optical waveguide is changed in response to a power applied to any one of the two metal heating wires.

Abstract: The present invention makes light input/output portions being a coupling portion with an optical fiber and a Y-branch using a rib waveguide, and a bending portion using a channel waveguide, wherein the rib waveguide and the channel waveguide is connected by a tapered waveguide. So that the present invention can improve the crosstalk, loss and operating voltage characteristics.

Abstract: The present invention relates to a multi-channel wavelength division multiplexer/demultiplexer capable of efficiently coupling or separating wavelength multiplexed optical signals. The multi-channel wavelength division multiplexer/demultiplexer according to the present invention comprises a band splitting means for splitting the band of wavelength multiplexed optical signals (&lgr;1˜&lgr;n) into M bands, a demultiplexing means for separating each band split by the band splitting means into a plurality of single wavelength channels, and a multiplexing means for coupling the single wavelength channels separated by the demultiplexing means. Therefore, the present invention can significantly increase the number of available wavelength channels while minimizing optical loss of wavelength channels.

Abstract: A wavelength converter for converting wavelength of a signal beam combined to a pump beam. The wavelength converter comprises a mode converting region for converting mode of the pump beam; a direction combining region for combining the signal beam to the pump beam; and wavelength converting region for converting the wavelength of the signal beam combined to the pump beam. The mode converting region and the wavelength converting region are formed as integrated by nonlinear polymeric material to construct a polymeric waveguide extended along propagation direction. The wavelength converting region includes the nonlinear polymer poled to a predetermined direction. According to the present invention, a DFG device, a cascade wavelength converting device, and second harmonic generation device of higher energy converting efficiency can be developed.

Abstract: A tunable Fabry-Perot filter is provided with two optical fibers each being coated with a high-reflective thin film at its one end, a silicon block for aligning the two optical fibers with each other having a pair of V-shaped grooves formed at both ends thereof, respectively, a resonant cavity medium of silicon or polymeric material having a high coefficient of thermo-optic effect, and a thermal electrode for applying heat to the resonant cavity medium.

Abstract: Disclosed is a thermo-optic tunable attenuator, which comprises a single mode channel optical waveguide, an optical waveguide of a Mach-Zehnder interferometer structure coupled with the single mode channel optical waveguide, the optical waveguide including two symmetric Y-branches, and two metal heating wires for applying power to one side of each of the two symmetric Y-branches, wherein the two metal heating wires are in a facing relationship with each other, wherein a refractive index of the optical waveguide is changed in response to a power applied to any one of the two metal heating wires.

Abstract: A method of fabricating a thermooptic tunable wavelength filter of optical communication systems using WDM is provided, which includes the steps of forming a polymer optical waveguide on a semiconductor substrate using a polymer material, forming a polymer Bragg grating on the optical waveguide using O2 RIE and polymer spin coating, and forming a thermooptic tuning electrode over the polymer optical waveguide in which the Bragg grating is integrated. This provides the thermooptical tunable wavelength filter which has very narrow wavelength band width of transmission signal, low crosstalk with optical signals adjacent thereto, stable wavelength tuning characteristic using thermooptic effect and wide tuning ranges. Furthermore, the optical devices using the polymer optical waveguide can be fabricated with low cost. Thus, they have advantages in terms of economy and marketability.