Abstract: A CAN type optical module according to the present invention includes a stem (201) including an insulating first plate-shaped member (201b) having an optical component (102) mounted on an inner surface thereof and a conductive second plate-shaped member (201a) having an opening and being fixed with the first plate-shaped member (201b) so as to cover the opening. A conductive CAN member (103) is fixed to the second plate-shaped member 201a so as to include the optical component (102) provided on the first plate-shaped member (201b). A plurality of lead terminals (203) are electrically connected with respective electrical wires from the optical component (102) and are fixed to an outside of the first plate-shaped member (201b).

Abstract: An element is mounted on a carrier by removing an oxide film sufficiently. An element mounting method in which electrodes of the element are fusion bonded to electrodes of the carrier so that the element is mounted on the carrier, the method includes the steps of: positioning the electrodes of the element at electrodes of carrier respectively, one of the electrodes of the carrier being a striped electrode in an arc shape formed on a concentric circle centered on one of the electrodes of the element, and another being a center electrode formed near the center location of the concentric circle; and then rubbing the striped electrode of the carrier and an electrode of the element together in a direction of the concentric circle centered the center electrode so as to fusion bond the electrodes.

Abstract: An element is mounted on a carrier by removing an oxide film sufficiently. An element mounting method in which electrodes of the element are fusion bonded to electrodes of the carrier so that the element is mounted on the carrier, the method includes the steps of: positioning the electrodes of the element at electrodes of carrier respectively, one of the electrodes of the carrier is a striped electrode in an arc shape formed on a concentric circle centering one of the electrodes of the element, and another is a center electrode formed near the center location of the concentric circle; and then rubbing the striped electrode of the carrier and the electrode of the element together in a direction of the concentric circle centering the center electrode so as to fusion bond the electrodes.

Abstract: A pin photo-diode 13 is used as a light reception device. When an input revel detection circuit 14 detects that an electrical signal outputted from pin photo-diode 13 exceeds a predetermined level, a transmittivity of an EA device 11 is dropped through an EA control circuit 12, and an externally supplied optical input signal is inputted through the EA device 11 to the pin photo-diode 13. Accordingly, a level of an optical signal to be inputted to the pin photodiode 13 can be always reduced to the predetermined level or less without any mount of an input protection circuit and without any usage of two EA devices.

Abstract: A wavelength multiplexing optical transmitting apparatus includes a plurality of optical transmitters for transmitting optical signals having mutually different wavelengths, a wavelength multiplexing circuit for wavelength multiplexing optical signals, an optical amplifier for directly amplifying the wavelength multiplexed optical signal and for producing an amplified multiplexed optical signal, an optical signal counting detector for branching the amplified multiplexed optical signal into signals of the respective wavelengths and for detecting the number of optical signals presently being transmitted, and an optical amplifier control circuit for controlling an output from the optical amplifier according to the number of optical signals; the optical amplifier includes a fiber made of a material to which a rare earth element is added and an excitation light to the fiber; the optical amplifier control circuit includes an excitation light control circuit for controlling an intensity of the excitation light accor

Abstract: In an optical transmission system in which an optical main signal and a monitoring control optical signal are wavelength-multiplexed and transmitted from a transmitter and the optical signal is directly amplified by a repeater and transmitted, low frequency pulse signals which are synchronized with the respective optical main signal and monitoring control signal are multiplexed with each others, a distance of a transmission section is specified by a phase difference between the low frequency pulse signals according to a difference in propagation rate of a transmission line due to a difference of wavelength between the optical main signal and the monitoring control signal and the optimal dispersion compensation is made possible even when a required dispersion compensation is changed due to a change of the transmission line by switching the optical transmission line to a DCF having an optimal amount of dispersion compensation.

Abstract: Optical signals transmitted from optical transmission panels are received by photodetectors, which detect the number of actually transmitted optical signals. A control signal depending on the number of optical signals detected is supplied to an optical amplifier. The intensity of a combined optical signal amplified by the control signal is controlled by controlling a current supplied to a pumping light source. Information representative of the number of optical signals detected is superposed onto the amplified optical signal by generating the current supplied to the pumping light source as a sine-wave signal depending on the detected number of optical signals. In a downstream optical repeater, the information representative of the number of optical signals is extracted, and the optical signal is amplified, after which the information representative of the number of optical signals is superposed again onto the amplified optical signal for transmission.