An optical fiber manufacturing method includes: drawing an optical fiber preform to form a bare optical fiber; cooling the bare optical fiber by a non-contact direction changer; adjusting a temperature of the bare optical fiber in a temperature adjusting unit disposed downstream of the non-contact direction changer and upstream of a coating unit; disposing, in the coating unit, an uncured coating layer that comprises a resin precursor on an outer periphery of the bare optical fiber; and curing the uncured coating layer in a curing unit.

A non-contact direction changer includes: a guide groove that guides an optical fiber and changes a direction of advancement of the optical fiber from a first direction to a second direction; a bottom ejection opening at a bottom of the guide groove; and one or more side ejection openings on at least one of opposite side surfaces of the guide groove. A fluid is ejected into the guide groove through the bottom ejection opening. A fluid is ejected into the guide groove through the one or more side ejection openings.

A non-contact direction changer includes: a guide groove that guides an optical fiber and changes a direction of advancement of the optical fiber from a first direction to a second direction; a bottom ejection opening at a bottom of the guide groove; and one or more side ejection openings on at least one of opposite side surfaces of the guide groove. A fluid is ejected into the guide groove through the bottom ejection opening. A fluid is ejected into the guide groove through the one or more side ejection openings.

A non-contact direction changer includes: a guide groove that guides an optical fiber and changes a direction of advancement of the optical fiber from a first direction to a second direction; a bottom ejection opening at a bottom of the guide groove; and one or more side ejection openings on at least one of opposite side surfaces of the guide groove. A fluid is ejected into the guide groove through the bottom ejection opening. A fluid is ejected into the guide groove through the one or more side ejection openings.

A non-contact direction changer includes: a guide groove that guides an optical fiber and changes a direction of advancement of the optical fiber from a first direction to a second direction; a bottom ejection opening at a bottom of the guide groove; and one or more side ejection openings on at least one of opposite side surfaces of the guide groove. A fluid is ejected into the guide groove through the bottom ejection opening. A fluid is ejected into the guide groove through the one or more side ejection openings.

An optical fiber manufacturing method includes: drawing an optical fiber preform to form a bare optical fiber; cooling the bare optical fiber by a non-contact direction changer; adjusting a temperature of the bare optical fiber in a temperature adjusting unit disposed downstream of the non-contact direction changer and upstream of a coating unit; disposing, in the coating unit, an uncured coating layer that comprises a resin precursor on an outer periphery of the bare optical fiber; and curing the uncured coating layer in a curing unit.

An optical fiber with low attenuation is provided. The fiber is produced under conditions that reduce fictive temperature. Processing includes maintaining the fiber at temperatures at or near the glass transition temperature (T.sub.g) for an extended period of time. For silica-based fibers, the preferred temperatures are temperatures between 1000 C. and 1700 C. The extended residence times are achieved in a continuous fiber manufacturing process by increasing the path length of the fiber through a processing region maintained at temperatures between 1000 C. and 1700 C. The increased path length is achieved by including one or more fluid bearing devices in the processing region. The extended residence time in the processing region allows the structure of the glass fiber to relax more completely and to more closely approach the equilibrium state. The more relaxed glass structure leads to a lower fictive temperature and provides fibers with lower attenuation.

An optical fiber with low attenuation is provided. The fiber is produced under conditions that reduce fictive temperature. Processing includes maintaining the fiber at temperatures at or near the glass transition temperature (T.sub.g) for an extended period of time. For silica-based fibers, the preferred temperatures are temperatures between 1000 C. and 1700 C. The extended residence times are achieved in a continuous fiber manufacturing process by increasing the path length of the fiber through a processing region maintained at temperatures between 1000 C. and 1700 C. The increased path length is achieved by including one or more fluid bearing devices in the processing region. The extended residence time in the processing region allows the structure of the glass fiber to relax more completely and to more closely approach the equilibrium state. The more relaxed glass structure leads to a lower fictive temperature and provides fibers with lower attenuation.

An optical fiber with low attenuation is provided. The fiber is produced under conditions that reduce fictive temperature. Processing includes maintaining the fiber at temperatures at or near the glass transition temperature (T.sub.g) for an extended period of time. For silica-based fibers, the preferred temperatures are temperatures between 1000 C. and 1700 C. The extended residence times are achieved in a continuous fiber manufacturing process by increasing the path length of the fiber through a processing region maintained at temperatures between 1000 C. and 1700 C. The increased path length is achieved by including one or more fluid bearing devices in the processing region. The extended residence time in the processing region allows the structure of the glass fiber to relax more completely and to more closely approach the equilibrium state. The more relaxed glass structure leads to a lower fictive temperature and provides fibers with lower attenuation.

An optical fiber with low attenuation is provided. The fiber is produced under conditions that reduce fictive temperature. Processing includes maintaining the fiber at temperatures at or near the glass transition temperature (T.sub.g) for an extended period of time. For silica-based fibers, the preferred temperatures are temperatures between 1000 C. and 1700 C. The extended residence times are achieved in a continuous fiber manufacturing process by increasing the path length of the fiber through a processing region maintained at temperatures between 1000 C. and 1700 C. The increased path length is achieved by including one or more fluid bearing devices in the processing region. The extended residence time in the processing region allows the structure of the glass fiber to relax more completely and to more closely approach the equilibrium state. The more relaxed glass structure leads to a lower fictive temperature and provides fibers with lower attenuation.