Abstract: An optical antenna system for a free-space communication system includes a fixed and an adjustable optical antenna assemblies. The fixed optical antenna assembly includes a dual wavelength optical transmitter assembly and a single wavelength receiver assembly. The dual wavelength optical transmitter assembly includes a convex lens with a focal point and a dual wavelength optical transmitter mounted at the focal point to produce a first and a second laser beam with different wavelengths. The adjustable optical antenna assembly includes a dual wavelength optical receiver assembly and a single wavelength transmitter assembly. The dual wavelength optical receiver assembly uses an optical splitter to direct the two laser beams respectively through two optical filters to an optical alignment detector and an optical data detector. Thereby saving cost, size and weight of the optical antenna system.

Abstract: A reflective optical apparatus for a free-space optical communication system includes a housing, an optical transceiver, a reflective member and the protective window. The housing has a front opening. The reflective member is mounted in the housing and has a reflective surface with a focal point, which faces the front opening. The optical transceiver is mounted at the focal point of the reflective surface. The protective window is mounted in the housing between the transceiver and the front opening of the housing. Consequently, the reflective member can be made of machinable materials, such as composite materials and can be machined precisely to form the reflective surface with an exact curvature and smooth surface. The materials and sizes of the reflective member are not restricted, and the objectives of being low cost and easy to machine in fabrication for the reflective optic apparatus are accomplished.

Abstract: A bearing assembly has a bottom base, a lower plate, an upper plate and a top base. At least one first locking device is configured between the lower plate and the bottom base. At least one second locking device is configured between the upper plate and the top base. Accordingly, the bearing assembly can bear a large shear stress by means of the locking devices. Enlarging the diameter of the bolts for attaching the lower plate to the bottom base or for attaching the upper plate to the top plate is not needed. The bearing assembly can bear a larger shear stress with fewer bolts than a conventional bearing assembly. The cost to manufacture the bearing assembly with a high structural strength is reduced.

Abstract: A prestressing device for a mechanical component of a mechanical finishing device has at least one rigid prestressing unit mounted in the mechanical component. This can provide a prestressing tension to the mechanical component. The bending and the deformation of the mechanical component can be prevented. The useful life of the mechanical finishing device is prolonged.

Abstract: A prestressing device for a mechanical component of a mechanical finishing device has at least one rigid prestressing unit mounted in the mechanical component. This can provide a prestressing tension to the mechanical component. The bending and the deformation of the mechanical component can be prevented. The useful life of the mechanical finishing device is prolonged.