Production method of polarization maintaining fiber

摘要

The invention provides a production method for a PMF. Two or more bores at regular intervals are formed in a glass rod including a core and a clad so that the bores may be located on a concentric circle around a center axis of the glass rod. A stress applying member is inserted into the bore. The glass rod and the stress applying member may be heated before or after inserting. The glass rod with the stress applying is drawn without exposure to the atmosphere after heating in order to form an optical fiber.