INFARED OPTICAL WAVEGUIDES FOR REMOTE POWERING OF SMALL UNDERSEA DEVICES

EXISTING LONG-LINE FIBER OPTIC LINKS UTILIZE VARIOUS LASER DIODES AS SOURCES; GRADED - INDEX, FUSED - SILICA CORE FIBERS AS THE TRANSMISSION MEDIA; AND PHOTO-DETECTING DIODES AS THE RECEIVING DEVICE. BY 1990 IT IS ESTIMATED THAT 10 PERCENT OF THE TOTAL COMMUNICATIONS CABLE INDUSTRY WILL UTILIZE THIS TRANSMISSION METHODOLOGY AS THE CONVENTIONAL, TWISTED WIRE PAIR WILL BE 10 8TH POWER TIMES MORE EXPENSIVE ON A COST/CHANNEL/KM BASIS. EVEN AS THE ATTENUATION OF THESE SYSTEMS DROPS, THE POSSIBILITY OF POWERING THE PRESENTLY REQUIRED REPEATERS AND OTHER DEVICES DIRECTLY BY EMPLOYING THE SAME METHODOLOGY SEEMS REMOTE WITHOUT THE INVENTION OF A SPECIALIZED SYSTEM, DESIGNED EXPLICITLY FOR THESE POWERING APPLICATIONS. SUCH A SYSTEM EMPLOYING IR WAVELENGTH LASER RADIATION WOULD ENJOY THREE MAJOR BENEFITS: (1) THE QUANTUM EFFICIENCY OF A THERMAL CONVERSION TRANSDUCER IMPROVES WITH INCREASING WAVELENGTH; (2) THE THEORETICAL POSSIBILITIES OF EMPLOYING DIRECT CONVERSION OF DELIVERED IR OPTICAL POWER IS CURRENTLY AVAILABLE FROM COMPACT, FULLY DEVELOPED IR LASERS. THUS, THIS PROPOSAL SEEKS TO INVESTIGATE THE THEORETICAL AND PRACTICAL LIMITATIONS OF ENERGY TRANSMISSION VIA OPTICAL LINKS AND BY ITS SUCCESSFUL COMPLETION SHALL DEFINE AND DEMONSTRATE NEW TECHNIQUES FOR IR POWERING OF REMOTE DEVICES.