Abstract:
The present invention relates to a method of manufacturing a waveguide using an ion exchange process. The present invention controls the refractive index and the thickness of a surface layer on a glass substrate using an ion exchange process, forms the waveguide pattern on the surface layer by means of photolithography and etching process and coats with materials having the refractive index same to or lower than that of the glass substrate to form a cladding layer. Accordingly, the present invention can manufacture a planar waveguide, which is excellent in dimension control and reproducibility and has a sharp step wall.
Abstract:
A high-speed wavelength channel selector has properties of relatively easy manufacturing and easy extension to multi-channel integration, and a high-speed space and wavelength multiplexed channel selector uses the high-speed wavelength channel selector. The high-speed wavelength channel selector is integrated with electro-optic waveguide switches of non-crystalline materials, such as electro-optic polymers or glasses, in the middle of a pair of wavelength multiplexer and demultiplexer and the high-speed space and wavelength multiplexed channel selector has the photonic integrated circuit-type composition of a space multiplexed channel selector containing M electro-optic waveguide switches and an M×1 channel combiner, the high-speed wavelength channel selector, optical amplifier and a high-speed wavelength converter.
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 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. The optical amplifier switch scheme, which provides a simultaneous optical switching and amplification in an optical waveguide form, allows the device fabricable in a compact integrated manner and more useful in practical applications. The optical amplifier switch in accordance with the present invention can replace the conventional optical switches of the prior art, and can promote technical development in the areas of high-capacity optical communication systems, massive optical signal processing, optical switching, optical computing, and so on.
Abstract:
An optical fiber Mach-Zehnder interferometer optical filter is disclosed. The filter includes a stabilization light source for varying a first wavelength of a light signal for stabilizing a Mach-Zehnder interferometer, first and second optical fiber couplers for receiving an optical signal from the stabilization light source and an optical signal of a second wavelength different from a first wavelength inputted from an input port and dividing into two parts having the same intensity for thereby forming a Mach-Zehnder interferometer, a polarization controller connected with one side of the first optical fiber coupler for controlling a polarization of the interfered light of the interferometer, first and second wavelength division multiplex optical couplers connected with the second optical fiber coupler for separately outputting a first wavelength optical signal and a second wavelength optical signal, an optical fiber phase modulator connected with the other side of the first optical fiber coupler for varying the length of the optical fiber in accordance with a fed-back phase difference, and a stabilization circuit for receiving two optical signals of the first wavelength from the first and second wavelength division multiplex optical couplers and feeding back the phase difference to the optical fiber phase modulator for thereby implementing a constant optical path difference of the interferometer.
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. According to the present invention, a resonator stabilizing apparatus in an optical fiber laser includes a non-linear optical amplitude loop mirror (NALM) for non-linearly amplifying a laser pumped laser light, a linear loop mirror of a closed loop shape for confining the laser light sufficiently amplified by the non-linear optical amplitude loop mirror; a light isolator for proceeding the light confined by said linear loop mirror only in one direction, an optical coupler for detecting the light proceeding in the direction opposite to the light isolator by the linear loop mirror, the phase of which is varied in the non-linear optical amplitude loop mirror, and a piezo-electric transducer (PZT) for performing a signal processing for minimizing the amount of light proceeding in an opposite direction when the light detector detects the light proceeding in the opposite direction and feedbacking again the light to stabilize the light, the light detector is coupled by the linear loop mirror and the optical 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. The present invention provides an apparatus for measurement of an optical pulse shape that is able to measure the waveform not with the repeated measurements but with a single shot measurement.
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. The number of polarization maintaining optical fibers carries the split light by the first optical fiber node. The phase modulator maintains phase difference between two birefringent axes of the polarization maintaining fibers. The stabilization electronics supply feedback signal to the phase modulator. The second optical fiber node connects the polarization maintaining fibers with the input of second polarization beam splitter with the angle of 45 degree between their birefringent axes, receives split light by said first optical fiber node, and generates interference signals. The second polarization beam splitter divides the interference signals into output signals by polarization axes. The wavelength division optical multiplexers divide the output signals into signals for the stabilization electronics and filtered signals by wavelengths.
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.
Abstract:
Provided is a polymeric optical device comprising a substrate, a lower cladding layer formed on the substrate, at least one core layer pattern formed on a predetermined region of the lower cladding layer and an upper cladding layer having at least two sub-upper cladding layers and formed on the lower cladding layer in which the core layer pattern is formed, and a method of fabricating the same, whereby birefringence of a polymeric optical device could be improved and polarization dependence could be reduced by adjusting the thickness of the sub-upper cladding layer and the number of stacks thereof.