This application relates generally to an optical fiber for the delivery of infrared light where the polarization state of the light entering the fiber is preserved upon exiting the fiber and the related methods for making thereof. The optical fiber has a wavelength between about 0.9 m and 15 m, comprises at least one infrared-transmitting glass, and has a polarization-maintaining (PM) transverse cross-sectional structure. The infrared-transmitting, polarization-maintaining (IR-PM) optical fiber has a birefringence greater than 10.sup.5 and has applications in dual-use technologies including laser power delivery, sensing and imaging.

This application relates generally to an optical fiber for the delivery of infrared light where the polarization state of the light entering the fiber is preserved upon exiting the fiber and the related methods for making thereof. The optical fiber has a wavelength between about 0.9 m and 15 m, comprises at least one infrared-transmitting glass, and has a polarization-maintaining (PM) transverse cross-sectional structure. The infrared-transmitting, polarization-maintaining (IR-PM) optical fiber has a birefringence greater than 10.sup.5 and has applications in dual-use technologies including laser power delivery, sensing and imaging.

This application relates generally to an optical fiber for the delivery of infrared light where the polarization state of the light entering the fiber is preserved upon exiting the fiber and the related methods for making thereof. The optical fiber has a wavelength between about 0.9 ?m and 15 ?m, comprises at least one infrared-transmitting glass, and has a polarization-maintaining (PM) transverse cross-sectional structure. The infrared-transmitting, polarization-maintaining (IR-PM) optical fiber has a birefringence greater than 10.sup.?5 and has applications in dual-use technologies including laser power delivery, sensing and imaging.

Disclosed are apparatuses and methods for growing thin crystal fibers via optical heating. The apparatuses may include and the methods may employ a source of optical energy for heating a source material to form a molten zone of melted source material, an upper fiber guide for pulling a growing crystal fiber along a defined translational axis away from the molten zone, and a lower feed guide for pushing additional source material along a defined translational axis towards the molten zone. For certain such apparatuses and the methods that employ them, the lower feed guide's translational axis and upper fiber guide's translational axis are substantially aligned vertically and axially so as to horizontally locate the source material in the path of optical energy emitted from the optical energy source, in some cases to within a horizontal tolerance of about 5 m.