Abstract: Light having components of frequencies f0, f+1 and f?1 outputted from an optical modulator (10) is monitored, a second light detection means (14b) measures the power P2 of all the components, and a first light detection means (14a) measures the power P1 with frequency f0 component cut out by a filter means (13). Based on these light receiving powers (P1) and (P2), phase differences imparted by the respective DC electrodes of Mach-Zehnder optical waveguides (MZ-A, MZ-B, MZ-C) of the optical modulator (10) are controlled. The control is performed to minimize the light receiving power (P1) and to maximize the light receiving power (P2).

Abstract: An optical modulator is provided which includes: an optical splitting part that splits an input light wave into two light waves; two optical waveguides that propagate the two light waves into which the input light wave is split, respectively; a first SSB modulating part that is provided in one of the two optical waveguides and modulates a light wave, which propagates into the first SSB modulating part, with a carrier frequency so that the light wave is converted into a different light wave having a single side band; a second SSB modulating part that is provided in the other of the two optical waveguides and modulates a light wave, which propagates into the second SSB modulating part, with a data signal in order to generate a signal light wave having a different single side band; and an optical combining part that combines the light wave modulated by the first SSB modulating part with the signal light wave generated by the second SSB modulating part.

Abstract: Light having components of frequencies f0, f+1 and f?1 outputted from an optical modulator (10) is monitored, a second light detection means (14b) measures the power P2 of all the components, and a first light detection means (14a) measures the power P1 with frequency f0 component cut out by a filter means (13). Based on these light receiving powers (P1) and (P2), phase differences imparted by the respective DC electrodes of Mach-Zehnder optical waveguides (MZ-A, MZ-B, MZ-C) of the optical modulator (10) are controlled. The control is performed to minimize the light receiving power (P1) and to maximize the light receiving power (P2).

Abstract: An optical modulator which magnifies a modulation index and reduces affection of SBS by suppressing a light source carrier component in an equivalent light source spectral width and performs more long-distance transmission by suppressing one of sideband spectrums generated by a modulation signal to reduce affection of fiber dispersion, having a light branch means that branches input light having a carrier component into two light waves; a SSB modulation means that modulates one branched wave and generates a wave having the carrier component and one sideband spectrum; an intensity adjustment means that adjusts intensity of the carrier component of the other wave; a phase adjustment means that adjusts the phase of the carrier component with respect to at least one of the two waves; and a multiplexing means that multiplexes the two waves passing through the modulation means, and the intensity and phase adjustment means, and emits output light.

Abstract: An optical modulator is provided which includes: an optical splitting part that splits an input light wave into two light waves; two optical waveguides that propagate the two light waves into which the input light wave is split, respectively; a first SSB modulating part that is provided in one of the two optical waveguides and modulates a light wave, which propagates into the first SSB modulating part, with a carrier frequency so that the light wave is converted into a different light wave having a single side band; a second SSB modulating part that is provided in the other of the two optical waveguides and modulates a light wave, which propagates into the second SSB modulating part, with a data signal in order to generate a signal light wave having a different single side band; and an optical combining part that combines the light wave modulated by the first SSB modulating part with the signal light wave generated by the second SSB modulating part.

Abstract: The present invention provides an optical modulation element module capable of stably operating for long periods without limiting the operating conditions. An optical modulation element module comprising an optical modulation element 12, a case 11 with said optical modulation element being integrated thereto, input output fibers 13, 14 being connected to said optical modulation element and also guided to an exterior of said case, a terminal for introducing a modulating signal and a bias adjustment voltage that are to be applied to said optical modulation element, said case being hermetically sealed, is characterized in that said case 11 is made of a material having almost the same coefficient of linear expansion as the optical modulation element 12, said optical modulation element is affixed to said case by using a thermoplastic and high-elastic adhesive material 19, a linear expansion difference between each material of said case and said fiber is less than 16×10?6/° C.

Abstract: An optical modulator which magnifies a modulation index and reduces affection of SBS by suppressing a light source carrier component in an equivalent light source spectral width and performs more long-distance transmission by suppressing one of sideband spectrums generated by a modulation signal to reduce affection of fiber dispersion, having a light branch means that branches input light having a carrier component into two light waves; a SSB modulation means that modulates one branched wave and generates a wave having the carrier component and one sideband spectrum; an intensity adjustment means that adjusts intensity of the carrier component of the other wave; a phase adjustment means that adjusts the phase of the carrier component with respect to at least one of the two waves; and a multiplexing means that multiplexes the two waves passing through the modulation means, and the intensity and phase adjustment means, and emits output light.

Abstract: The present invention provides an optical modulation element module capable of stably operating for long periods without limiting the operating conditions. An optical modulation element module comprising an optical modulation element 12, a case 11 with said optical modulation element being integrated thereto, input output fibers 13, 14 being connected to said optical modulation element and also guided to an exterior of said case, a terminal for introducing a modulating signal and a bias adjustment voltage that are to be applied to said optical modulation element, said case being hermetically sealed, is characterized in that said case 11 is made of a material having almost the same coefficient of linear expansion as the optical modulation element 12, said optical modulation element is affixed to said case by using a thermoplastic and high-elastic adhesive material 19, a linear expansion difference between each material of said case and said fiber is less than 16×10?6/° C.

Abstract: A method and device for stabilizing operation point and optical output of an external optical modulator. A low-frequency signal below a lower limit of signal frequency band of an input signal inputted to optical modulator is superimposed onto direct current bias. A low-frequency component included in detector output is extracted. On the basis of the low-frequency signal, output of the low-frequency component is normalized, and output-light of light source is controlled in accordance with normalized low-frequency component. Means of controlling optical output of light source, in control of output-light of light source, detects the output-light, compares the value of detected output-light to a standard value of primary optical output, and adjusts the output-light. The standard value is modified according to a ratio of primary value of normalized low-frequency component to a subsequent value, and means controlling optical output of light source is operated on the basis of modified standard value.

Abstract: “This invention offer optical modulator module with fulfilling the effective and the stable optical modulation, which stabilizes the emission of semiconductor and control the shift of optic axis between the optical component by the temperature change and so on, when using the semiconductor laser. Peculiarly, the optical modulator module includes, in same package, the semiconductor laser (27) as light source, the optical modulation device (28) that has optical waveguide on the surface of the chip made by the element of the electro-optical effect, and the polarization rotating element (40) between said semiconductor laser and said optical modulation device, for bringing plane of polarization of light from said semiconductor laser (27) to optimum plane of polarization in waveguide of the said optical modulation device in line and blocking the returning light from said optical modulation device to said semiconductor laser.

Abstract: The purpose of present invention is to provide the method and device for stabilizing the operation point and optical output of external optical modulator, which can control the wave pattern deformation of electrical signal array and set up stably the operation point of modulation curve of optical modulator and the optical output from optical modulator, even in case there is an optical output variation of the light source itself or a transmission factor variation in optical modulator.

Abstract: This invention offer optical modulator module with fulfilling the effective and the stable optical modulation, which stabilizes the emission of semiconductor and control the shift of optic axis between the optical component by the temperature change and so on, when using the semiconductor laser.

Abstract: A laser applying apparatus is provided with a laser source, setting means for setting the intensity of laser light applied to a portion to be irradiated, excitation means disposed in the laser source for selecting a stage of laser light intensity conforming to the set value by the setting means from among a plurality of stages of laser light intensity and causing it to be output from the laser source, and adjusting means disposed in the optical path for adjusting the intensity of the laser light output from the laser source to the intensity set by the setting means, by varying the light attenuation rate.

Abstract: A cornea thickness measuring ultrasonic probe is provided with an ultrasonic wave propagation layer being in contact with an eye to be examined and formed substantially concentrically with the center of curvature of the cornea of the eye to be examined, a plurality of ultrasonic wave vibrators are disposed on at least one meridian, and a fixation light source is presented to the eye to be examined.

Abstract: An eye refractive power measuring apparatus having a unit for projecting a plurality of index images onto the fundus of an eye to be examined, a unit for detecting the eye fundus reflected light beams of the index images correspondingly to each measuring meridian direction, a unit for operating the refractive power of the eye on the basis of the output of the detecting means, a unit for moving a fixation target for fixing the eye to be examined thereto or the projection system thereof in the direction of the optic axis, and a unit for controlling the movement speed of the fixation target or the projection system thereof on the basis of the degree of variation in the result of the measurement of the operated refractive power of the eye which results from the movement.

Abstract: A light metering system for obtaining a light value by scanning the brightness distribution of the object space within a predetermined field of view. Of the thus-produced brightness signals, those which correspond to a particular target area in the view-field are given respective predetermined weights. The light value is derived on the basis of these weighted signals and the remaining signals.

Abstract: A distance detecting device comprising radiation projecting means for projecting a radiation beam; radiation sensing means which is disposed away from the radiation projecting means with a given length and is arranged to receive a reflected radiation beam coming from an object whose distance is to be detected as the radiation beam is projected from the projecting means; and movable means for relatively varying the incident condition of the projected radiation beam onto the sensing means. The distance to the object is found either by the position of the movable means or by the amount of displacement thereof which occurs at a time point at which the sensing means optimally receive the reflected radiation beam coming from the object in the process of relatively varying the incident condition of the projected radiation beam onto the sensing means.

Abstract: In the device disclosed, an image formed by an optical system is scanned by an image sensor composed of independently arranged photoelectric transducing elements to produce an image scanning signal. A detecting circuit detects the variation of the brightness between the adjacent image elements as a measure of the sharpness of the image and the focus of the optical system. The focus detection accuracy is improved by non-linear transformation of the brightness variation signal with a non-linear transformation circuit that weighs the brightness variation signal on the basis of the signal level. A signal forming circuit detects the difference between the outputs of transducing elements and adds the differences to produce a comparator signal when a predetermined relationship is reached between the sharpness indication and the addition signal.

Abstract: In the device disclosed, an image formed by an optical system is scanned by an image sensor composed of independently arranged photoelectric transducing elements to produce an image scanning signal. A detecting circuit detects the variation of the brightness between the adjacent image elements as a measure of the sharpness of the image and the focus of the optical system. The focus detection accuracy is improved by non-linear transformation of the brightness variation signal with a non-linear transformation circuit that weighs the brightness variation signal on the basis of the signal level.

Abstract: An eye-fundus camera provides change-over and selection between automatic focusing and manual focusing. The eye-fundus camera includes a projector, a photo-sensor array, a focus controller and an illuminator. The projector projects a first focus mark and a second focus mark on the fundus of an eye to be examined. The photo-sensor array detects the first focus mark reflected from the fundus and the output from the sensor array is introduced into the controller to adjust the focus of the camera. The illuminator illuminates the fundus uniformly with light within a first wavelength range. The first focus mark is with light within the first wavelength range and within a second wavelength range other than the first one whereas the second focus mark is formed only of light within the first wavelength range. The eye-fundus camera further comprises a wavelength selecting mirror which cuts off light of the first wavelength range among rays of light incident upon the photo-sensor array.