PHOTON NUMBER AMPLIFIER FOR OPTICAL COMMUNICATIONS AND DETECTIONS

THE NOVEL CONCEPT OF PHOTON NUMBER AMPLIFIER HAS BEEN RECENTLY SUGGESTED, WHICH IS QUANTUM DEVICE CAPABLE OF NOISE-FREE AMPLIFICATION OF THE INPUT SIGNAL PHOTON NUMBER. NO EXPERIMENTAL PROGRESS ON THE REALIZATION OF THIS DEVICE HAS YET BEEN REPORTED. IN PRINCIPLE, PHOTON NUMBER AMPLIFIER CAN GREATLY IMPROVE THE SENSITIVITY OF DIRECT OPTICAL DETECTION WHICH IS IMPORTANT IN MANY SCIENTIFIC AND TECHNOLOGICAL APPLICATIONS. IT CAN ENHANCE THE DATA RATE BY UP TO AN ORDER OF MAGNITUDE COMPARED TO ORDINARY AMPLIFIERS IN A CONVENTIONAL OPTICAL COMMUNICATION LINK. IT CAN LEAD TO GREATLY IMPROVED OPTICAL COMMUNICATIONS BY ORDERS OF MAGNITUDE IN CONJUNCTION WITH INTENSITY-SQUEEZED SOURCES. IN THIS REPORT PROPOSE TO ANALYZE THREE NEW SCHEMES WHICH PROMISE TO PROVIDE EFFECTIVE REALIZATIONS OF PHOTON NUMBER AMPLIFIER. ONE OF THESE SCHEMES DOES NOT INVOLVE ELECTRONIC INTERMEDIATE PROCESSING AND CAN THUS OPERATE AT PICO- AND FEMTO-SECOND RATE. WE WILL ANALYTICALLY DERIVE THE AMPLIFIER PERFORMANCE OF THESE SCHEMES IN A REALISTIC IMPLEMENTATION AS A FUNCTION OF THE SYSTEM PARAMETERS. THE RESULTS WILL ENABLE US TO DESIGN THE MOST EFFICIENT EXPERIMENTS DEMONSTRATING NOISE-FREE PHOTON NUMBER AMPLIFICATION. ANTICIPATED BENEFITS/POTENTIAL APPLICATIONS - BY REPLACING ORDINARY OPTICAL AMPLIFIERS BY PHOTON NUMBER AMPLIFIERS, ONE CAN ENHANCE THE PERFORMANCE OF ANY DIRECT DETECTION OPTICAL COMMUNICATION OR SIGNAL PROCESSING SYSTEM BY A MODERATE TO A LARGE AMOUNT DEPENDING ON THE SITUATION, FOR BOTH COMMERCIAL AND MILITARY APPLICATIONS.