Abstract: A resonance type optical modulator includes an optical path having electro-optical effect characteristics, a modulation electrode formed along the optical path for applying an electric field to the optical path, a common electrode formed in opposition to the modulation electrode, a feeding line that is connected to the modulation electrode and stubs connected to the feeding line, wherein the feeding line, stubs and common electrode are provided on one side of a region that is divided by the modulation electrode.

Abstract: A wavelength stabilization module which can restrain light reflected by the fiber grating from returning to a light source, and a stable wavelength laser beam generating device. A wavelength stabilization module of the invention comprises an optical splitter 122 for splitting light lead from a light source 110 through a fiber 143 into first and second lights, a fiber grating 210 which has light of a specific wavelength in the first light pass therethrough and reflects light of the other wavelengths in the first light, and a light quantity change operating unit 311 for detecting a change in quantity of light passing through the fiber grating using the second light as reference light, and is configured to direct light, reflected by the fiber grating 210, to the outside of the fiber, and is configured to feed back the detected change in light quantity to the light source 110.

Abstract: A resonance type optical modulator includes an optical path having electro-optical effect characteristics, a modulation electrode formed along the optical path for applying an electric field to the optical path, a common electrode formed in opposition to the modulation electrode, a feeding line that is connected to the modulation electrode and stubs connected to the feeding line, wherein the feeding line, stubs and common electrode are provided on one side of a region that is divided by the modulation electrode.

Abstract: A method of stabilizing the frequency of a semiconductor laser comprises stabilizing a time-dependent frequency fluctuation by utilizing an optical energy absorption medium including an isotope acetylene gas molecule. An apparatus for stabilizing the frequency of a semiconductor laser, comprises a semiconductor laser, an optical energy absorption medium, a photodetector and a control circuit as essential elements. The optical energy absorption medium includes an isotope acetylene molecule.

Abstract: A nonlinear optical device having an optical medium and an optical element including a polarizer, an optical resonator and a reflector is provided. The optical medium includes an organic nonlinear optical material represented by a formula: ##STR1## wherein each of R.sub.1 and R.sub.2 is an alkyl group having 2 to 6 carbon atoms or a hydroxyalkyl group having 2 to 6 carbon atoms, R.sub.1 and R.sub.2 being same or different groups; or R.sub.1 is an ethyl group and R.sub.2 is an acryloyloxyethyl group (CH.sub.2 .dbd.CH--COO--CH.sub.2 CH.sub.2 --) or a methacryloyloxyethyl group (CH.sub.2 .dbd.C(CH.sub.3)--COO--CH.sub.2 CH.sub.2 --); and each of X.sub.1, X.sub.2, X.sub.3, and X.sub.4 is individually a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, an alkoxy group, an alkyl ester group, or an alkylamide group, where X.sub.1, X.sub.2, X.sub.3 and X.sub.4 may be the same or different groups.

Abstract: An organic nonlinear optical device having a nitrostyrene compound represented by a formula: ##STR1## wherein R.sub.1 is an ethyl group R.sub.2 is a group selected from the group consisting of an acryloyloxyethyl group (CH.sub.2 .dbd.CH--COO--CH.sub.2 CH.sub.2 --) and a methacryloyloxyethyl group (CH.sub.2 .dbd.C(CH.sub.3)--COO--CH.sub.2 CH.sub.2 --); and X.sub.1, X.sub.2, X.sub.3, and X.sub.4 are the same or different and each is selected from the group consisting of a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, an alkoxy group, an alkyl ester group, and an alkylamide group, is provided.