Abstract: A vehicle steering device includes a turning shaft held in a housing so as to be movable in the axial direction, a ball screw transmitting drive force produced by an electric motor to the turning shaft, a bearing supporting a nut, which is a component of the ball screw, so as to be rotatable relative to the housing, and annular elastic members that support side faces of the bearing in the axial direction of the turning shaft across the entire circumference, and are formed of an elastic material. The elastic members include respective first elastic portions having a first load characteristic that gently increases the ratio of compression load per a unit compression amount deforming in the axial direction of the turning shaft, and respective second elastic portions having a second load characteristic that keenly increases the ratio in comparison with the first load characteristic.

Abstract: A vehicle steering device includes a turning shaft held in a housing so as to be movable in the axial direction, a ball screw transmitting drive force produced by an electric motor to the turning shaft, a bearing supporting a nut, which is a component of the ball screw, so as to be rotatable relative to the housing, and annular elastic members that support side faces of the bearing in the axial direction of the turning shaft across the entire circumference, and are formed of an elastic material. The elastic members include respective first elastic portions having a first load characteristic that gently increases the ratio of compression load per a unit compression amount deforming in the axial direction of the turning shaft, and respective second elastic portions having a second load characteristic that keenly increases the ratio in comparison with the first load characteristic.

Abstract: A fiber laser includes: a solid laser fiber doped with a rare earth element; a first grating fiber provided at one end portion of both ends along an optical axis direction of the solid laser fiber; and a first reflective element provided at the other end portion of the solid laser fiber. The first and second reflective elements constitute a resonator structure for the solid laser fiber; the first grating fiber Bragg-reflects only two polarizations of a first polarization having a first wavelength, and a second polarization having a second wavelength different from the first wavelength and being mutually orthogonal with the first polarization in a polarization direction; and at least one reflection wavelength of light which is reflected at the first reflective element and either one wavelength of the two polarizations which are Bragg-reflected at the first grating fiber coincide with each other.

Abstract: Fiber laser unit 1 comprises a plurality of fiber lasers 2 and 3 that generate laser beams by exciting a laser active substance inside cores 2a and 3a by exciting light, propagate the laser beams inside the cores 2a and 3a, and output the laser beams from the end portions 2c and 3c, wherein the respective fiber lasers 2 and 3 have resonators 4 and 5 that reflect the laser beams on both ends 2b, 2c, 3b, and 3c thereof and have a structure in which a part of the cores 2a and 3a is reduced in diameter, the diameter reduced portions of the cores 2a and 3a are made proximal to each other, injection synchronization is carried out inside the resonators 4 and 5 by laser beams leaked from the cores 2a and 3a, and a loss is applied to the port of either one of the fiber lasers 2 and 3.

Abstract: Fiber laser unit 1 comprises a plurality of fiber lasers 2 and 3 that generate laser beams by exciting a laser active substance inside cores 2a and 3a by exciting light, propagate the laser beams inside the cores 2a and 3a, and output the laser beams from the end portions 2c and 3c, wherein the respective fiber lasers 2 and 3 have resonators 4 and 5 that reflect the laser beams on both ends 2b, 2c, 3b, and 3c thereof and have a structure in which a part of the cores 2a and 3a is reduced in diameter, the diameter reduced portions of the cores 2a and 3a are made proximal to each other, injection synchronization is carried out inside the resonators 4 and 5 by laser beams leaked from the cores 2a and 3a, and a loss is applied to the port of either one of the fiber lasers 2 and 3.