Abstract: A detection device is provided with a light-receiving module configured to output an electrical signal according to a power of an input light received at a light-receiving surface, an optical lens configured to collimate and guide to the light-receiving surface the input light from the outside, and at least one condensing unit that is provided in a path of the input light between the optical lens and the light-receiving surface and configured to decrease a beam diameter of the input light at the light-receiving surface.

Abstract: A detection device is provided with a light-receiving module configured to output an electrical signal according to a power of an input light received at a light-receiving surface, an optical lens configured to collimate and guide to the light-receiving surface the input light from the outside, and at least one condensing unit that is provided in a path of the input light between the optical lens and the light-receiving surface and configured to decrease a beam diameter of the input light at the light-receiving surface.

Abstract: A light from an optical fiber is incident on a dispersive element via an optical circulator and an optical fiber. The dispersive element disperses the incident light toward directions different depending on wavelength to apply the dispersed lights to a lens. The lens focuses the lights at positions different for each wavelength of the light. The patterning plate has desired reflection characteristics. The lights reflected on the patterning plate are multiplexed by the dispersive element through the identical path to be emitted from an optical fiber via the optical circulator. Desired characteristics can be obtained by arbitrarily changing a pattern with reflection characteristics of the patterning plate. In addition, a characteristic of the optical filter can be changed by moving the patterning plate.

Abstract: A light from an optical fiber is incident on a dispersive element via an optical circulator and an optical fiber. The dispersive element disperses the incident light toward directions different depending on wavelength to apply the dispersed lights to a lens. The lens focuses the lights at positions different for each wavelength of the light. The patterning plate has desired reflection characteristics. The lights reflected on the patterning plate are multiplexed by the dispersive element through the identical path to be emitted from an optical fiber via the optical circulator. Desired characteristics can be obtained by arbitrarily changing a pattern with reflection characteristics of the patterning plate. In addition, a characteristic of the optical filter can be changed by moving the patterning plate.

Abstract: A downlink signal and WDM-PON signal from an OLT 1 are separated by an optical filter part 11, and a downlink signal is split by a power splitter part 12. A WDM-PON signal is also split in each wavelength by a demultiplexer part 13, and a downlink signal and a WDM-PON signal of either one of the wavelengths are outputted to each ONU, in an optical filter part 14. Moreover, an uplink signal from the ONU is introduced to the power splitter part 12 via the optical filter part 14, and outputted to the OLT 1 via the optical filter part 11. Therefore, it is possible to realize a hybrid splitter module which allows upgrading a downlink signal to a WDM-PON without adding changes to a device on a subscriber side.

Abstract: In order to realize an optical attenuator which has an attenuation factor independent of the wavelength of incident light, a glass substrate is used in an attenuator plate, and the glass substrate is formed in a tapered section so that its incident and exit planes may not be parallel to each other. On one side thereof, a metal film corresponding to the attenuation factor is formed. Also one side of the glass substrate is covered with an antireflection coating for canceling the wavelength dependence of the metal film. Thereby ripple of attenuation factor due to wavelength can be eliminated, and the wavelength dependence may be minimized.

Abstract: In order to realize an optical attenuator which has an attenuation factor independent of the wavelength of incident light, a glass substrate is used in an attenuator plate, and the glass substrate is formed in a tapered section so that its incident and exit planes may not be parallel to each other. On one side thereof, a metal film corresponding to the attenuation factor is formed. Also one side of the glass substrate is covered with an antireflection coating for canceling the wavelength dependence of the metal film. Thereby ripple of attenuation factor due to wavelength can be eliminated, and the wavelength dependence may be minimized.

Abstract: In order to realize an optical attenuator which has an attenuation factor independent of the wavelength of incident light, a glass substrate is used in an attenuator plate, and the glass substrate is formed in a tapered section so that its incident and exit planes may not be parallel to each other. On one side thereof, a metal film corresponding to the attenuation factor is formed. Also one side of the glass substrate is covered with an antireflection coating for canceling the wavelength dependence of the metal film. Thereby ripple of attenuation factor due to wavelength can be eliminated, and the wavelength dependence may be minimized.

Abstract: The light emitted by a laser diode 1 is entered into a beam splitter 5, and its reflected light is given to an optical band pass filter 8. The light passing through the optical band pass filter 8 is received by a photo diode PD1.The light once reflected by the optical band filter 8 and passing through the beam splitter 5 is received by a photo diode PD2. The reception ratio of the photo diodes PD1, PD2 is calculated in output ratio calculator 9. By controlling the emission wavelength of the laser diode 1 so that its ratio may be constant, laser light of high precision and stable wavelength is emitted.

Abstract: A wavelength locker 4 is provided at one light beam exit end of a laser diode 1. The wavelength locker 4 incorporates an interference optical filter 3, and photo diodes PD1, PD2 for detecting its transmitted light and reflected light. A thermistor 15 and a temperature detector 14 for detecting the temperature of the interference optical filter 3 are provided. Calculating the output ratio of the photo diodes PD1, PD2, the wavelength is controlled so that the correction value by the temperature of the output ratio may be a specified value. The laser diode 1 and wavelength locker 4 are sealed in an optical module 11, and mounted on a substrate together with other blocks. Thus is obtained a laser light source apparatus composed in a simple and small constitution within a emission possible wavelength range of laser light source and capable of emitting stably.

Abstract: The light emitted by the laser diode 1 is put into an interference optical filter 5. The light passing through the interference optical filter 5 and the reflected light are respectively received in photo diodes PD1, PD2. Their output ratio is calculated by an adder 13, a subtracter 14, and a divider 15, and a wavelength signal is obtained. The difference of the output ratio and reference value is detected as error signal by an error detector 16, and the emission wavelength of the laser diode 1 is controlled so that the error signal may be zero.

Abstract: An optical waveguide device includes an optical waveguide formed on a surface of a substrate having an electrooptical effect, and a pair of electrodes formed on corresponding regions above the optical waveguide and receiving a driving electric signal thereacross. By applying the electric signal to the electrodes, an electric field is formed in a vicinity of the optical waveguide. By changing a distribution of the electric field in accordance with a change in a frequency of the electric signal, it is possible to suppress a DC drift of the device to effectively compensate a fluctuation in operational characteristics due to the DC drift, stress of the like.

Abstract: A method of connecting optical fibers with each other or with optical waveguides using a connection aid. The connecting aid has a hole into which the fiber is inserted and secured and from which hole a tip portion of the fiber protrudes slightly, and an adhesive or solder is applied to a gap between two adjacent connection aids or between an end surface of the waveguide and an opposed surface of the connection aid. The connection aid may contain an array of two or more optical fibers. The connection method can be used to produce reliable, strong and low-loss connections between the optical fibers or between and optical waveguide and the optical fibers.