Optical coupling with electric field rotation

摘要

An optical coupling device for coupling a semiconductor laser emitting a diverging laser light to a converging optical system converging the laser light onto a rectangle end surface of an optical wavelength converter, comprises: a rotator for rotating the semiconductor laser about an optical axis thereof; a collimator disposed in the optical axis for converting the diverging laser light to a parallel beam along the optical axis; and a polarization rotator for rotating a plane of the electric field vibration of the parallel beam about the an optical axis to guide the beam to the converging optical system, thereby controlling the plane of the electric field vibration direction of the fundamental wave to couple the fundamental wave to a rectangle end surface at a high efficiency.