Abstract: A floating connector includes a movable housing accommodated in an accommodation portion of a stationary housing in a loosely fitted state and a terminal integrally formed of a single member. The terminal includes a first fixed portion fixed to a first fixing portion of the stationary housing, a second fixed portion fixed to a second fixing portion of the movable housing, a mating terminal fitting portion, and an elastic portion coupling the first fixed portion and the second fixed portion. The elastic portion is elastically deformable along with movement of the movable housing with respect to three orthogonal directions including a connector fitting direction.

Abstract: An electrical connector includes a housing and a contact having a bellows contact structure. The contact has a substantially rectangular parallelepiped frame body including an upper-surface portion, a lower-surface portion, and a pair of side surface portions facing each other therebetween. At one end of the substantially rectangular parallelepiped frame body in a longitudinal direction, a contact-spring portion for contacting with a mating terminal is provided. At the other end of the substantially rectangular parallelepiped frame body in the longitudinal direction, a fixing portion that is fixed to the housing is provided. The contact has an elastic structure that is included in the substantially rectangular parallelepiped frame body interposed between the contact-spring portion and the fixing portion. The elastic structure of the contact is segmented into the upper-surface portion, the pair of side-surface portions, and the lower-surface portion of the substantially rectangular parallelepiped frame body.

Abstract: An optical direct amplifier device can detect failure of an excitation light source without using an electric circuit even when a monitoring system of the optical direct amplifier device based on a line turning back is employed. The optical direct amplifier device includes first and second optical amplifiers respectively amplifying signal lights of first and second transmission path. The optical direct amplifier device has a monitoring circuit branching only monitoring light wavelength of different from a wavelength of the signal lights and extracting means for extracting a part of an excitation light incided to the optical amplifiers.

Abstract: An optical direct amplifier device can detect failure of an excitation light source without using an electric circuit even when a monitoring system of the optical direct amplifier device based on a line turning back is employed. The optical direct amplifier device includes first and second optical amplifiers respectively amplifying signal lights of first and second transmission path. The optical direct amplifier device has a monitoring circuit branching only monitoring light wavelength of different from a wavelength of the signal lights and extracting means for extracting a part of an excitation light incided to the optical amplifiers.

Abstract: An optical direct amplifier includes an O/E converter for converting a branched output light into an electric signal, a frequency variable filter for detecting a modulated frequency specific to a signal light from the electric signal, a counter for counting the number of modulated frequencies detected, and a control circuit. When the count value (number of signal lights) output from the counter changes, the control circuit controls the output of the optical direct amplifier such that the optical output level per signal light can be equal to the optical output level per signal light indicated before the count value (number of signal lights) changes.

Abstract: Output light beams from first and second laser diodes are combined by a first optical polarization combiner, and output light beams from third and fourth laser diodes are combined by a second optical polarization combiner. Combined light beams from the first and second optical polarization combiners are multiplexed by an optical multiplexer/demultiplexer into a light beam, which is demultiplexed thereby into first and second pumping light beams to be applied to first and second rare-earth-doped fibers in upstream and downstream optical direct amplifiers.