Infrared-transmitting, polarization-maintaining optical fiber and method for making

A method of making an infrared-transmitting, polarization maintaining (IR-PM) optical fiber, comprising:

• making a preform with an approximately round cross-sectional shape comprising an approximately round core surrounded by a cladding, wherein the preform comprises an infrared-transmitting, non-silica glass;
• compressing the preform to form a compressed preform where both the core and cladding have an approximately elliptical shape;
• altering the compressed preform by grinding, polishing, machining, or any combination thereof to make an altered preform with an approximately round cladding;
• and
• drawing the altered preform into a fiber that is approximately round with an approximately elliptical core, wherein the fiber has a birefringence greater than 10−5.