Transmissive polarization control device, optical isolator, polarization variable light source, and method of manufacturing transmissive polarization control device

A manufacturing method of a transmissive polarization control device, comprising:

• providing a semiconductor layer having a first surface and a second surface opposite to the first surface, a first electrode disposed on the first surface of the semiconductor layer, and a second electrode disposed on the second surface of the semiconductor layer, the semiconductor layer comprising:
• a first conductivity type region having a conductivity type that is one of p-type and n-type,
• a second conductivity type region having a conductivity type that is the other of p-type and n-type, and
• a pn junction located between the first conductivity type region and the second conductivity type region;
• irradiating the semiconductor layer with laser light while a forward current flows between the first electrode and the second electrode, to form a near-field light formation region in which an impurity of the first conductivity type for formation of near-field light is distributed;
• removing the first electrode and the second electrode;
• and
• forming a loop electrode through which an electric current flows to produce a magnetic field in a direction penetrating the pn junction, the loop electrode disposed on the first surface.