RADIATION HARD GRADED INDEX OPTICAL FIBERS DEVELOPMENT

OPTICAL FIBERS ARE BEING CONSIDERED IN THE DESIGNS OF MANY MILITARY SYSTEMS BECAUSE OF THE NUMEROUS ADVANTAGES INCLUDING EMP AND EMI. HIGH BANDWWIDTH AND/OR LONG RUN SYSTEMS REQUIRES GRADED INDEX FIBERS. ALL COMMERCIALLY AVAILABLE FIBERS SHOW HIGH PERMANENT AND TRANSIENT RADIATION INDUCED OPTICAL LOSSES AND, THEREFORE, DO NOT MET THE NUCLEAR VULNERABILITY REQUIREMENTS OF MANY SYSTEMS. THIS PROGRAM PROPOSES NEW GLASS COMPOSITION WHICH WILL HAVE LOW RADIATION RESPONSE IN THE RESULTING FIBER. THE PROPOSED DOPANT FORM STABLE GLASS AND DOES NOT PRODUCE INTRINSIC ABSORPTION BANDS IN THE WAVELENGTH RANGE OF INTEREST. THE NATURE OF COLOR CENTER FORMATION IN TELECOMMUNICATION FIBERS WILL BE INVESTIGATED IN THE GEO2.SIO2 SYSTEM. SMALL AMOUNT OF CERIUM DOPING WILL BE INTRODUCED WITH THE CORE FIBER CHEMICALS UNDER VARIOUS REDOX CONDITIONS. RADIATION INDUCED COLORATION WILL BE INVESTIGATED USING OPTICAL ABSORPTION SPECTRONSCOPY AND ELECTRON MAGNETIC RESONANCE. TEST RESULTS WILL BE USED TO ESTABLISH REDOX CONDITION FOR MULTIVALENT ELEMENTS OTHER THAN CE AND SB, KNOWN TO FORM STABLE GLASSES WHICH DO NOT EXHIBIT STRONG OPTICAL ABSORPTION IN THE WAVELENGTH OF INTEREST. THE REDOX CONDITION WILL BE CORRELATED WITH THE OPTICAL FIBER RESPONSE TO PULSED AND STEADY STATE IONIZING RADIATION.