Abstract: A floating body (4) for a spar-type offshore wind power generation facility floating sideways is raised by injecting ballast water at sea, by steps including a first step of decentering a center of gravity of the floating body for the spar-type offshore wind power generation facility by means of a center-of-gravity decentering device, and a second step of injecting the ballast water to raise upright the floating body for the spar-type offshore wind power generation facility. The center-of-gravity decentering device may be a weight (2) attached to an outer surface of the floating body, or a solid ballast (34) introduced in the floating body.

Abstract: This optical coupler for coupling a plurality of visible light beams having different wavelengths includes: a substrate made of a material different from lithium niobate; and an optical coupling function layer formed on a main surface of the substrate. The optical coupling function layer includes: two multimode-interference-type optical coupling parts; optical-input-side waveguides and an optical-output-side waveguide connected to one multimode-interference-type optical coupling part, and optical-input-side waveguides and an optical-output-side waveguide connected to the other multimode-interference-type optical coupling part. The multimode-interference-type optical coupling parts, the optical-input-side waveguides, and the optical-output-side waveguides are made of a lithium niobate film.

Abstract: A motor includes a stator, a rotor, and a magnetic sensor. The stator includes an annular stator core. The stator core surrounds a central axis extending in an axial direction. The rotor is rotatable about the central axis. The rotor includes a first magnet, a second magnet, and a spacer. The first magnet is outward in a radial direction with respect to the stator core. The second magnet extends in one axial direction with respect to the first magnet and the stator core. The spacer is between the first magnet and the second magnet in the axial direction. The magnetic sensor detects a magnetic force of the second magnet. The spacer is made of a non-magnetic material.