The fixed frame length maximum correlation method which is the optimum methodover the binary symmetric channel has been proved.With Poisson distribution,the frame syncacquisition probability is obtained and followed b...The fixed frame length maximum correlation method which is the optimum methodover the binary symmetric channel has been proved.With Poisson distribution,the frame syncacquisition probability is obtained and followed by computer simulation.By Markov modelingtechniques,the probability and the mean time into lock mode are given.Finally,it is shown thatthe optimum frame sync method is far superior to conventional,and it is very useful in practice.展开更多
Enhancing the photoluminescence and depressing the background emission are important problems in rare earth ion-doped materials. In this letter, the two-photon absorption （TPA） probability in a Pr3＋ ion system is e...Enhancing the photoluminescence and depressing the background emission are important problems in rare earth ion-doped materials. In this letter, the two-photon absorption （TPA） probability in a Pr3＋ ion system is enhanced by a factor of 12.3 by a π-phase step scanning of ultrashort laser pulses. This level is significantly higher than that achieved by a transform-limit pulse. However, the laser intensity of shaped pulse is reduced to 37% of the initial transform-limited pulse. In this method, the TPA probability can also be reduced to 58%. Furthermore, the el＇feet of the shift of the intermediate energy level and the bandwidth of final states on TPA probability is discussed.展开更多
文摘The fixed frame length maximum correlation method which is the optimum methodover the binary symmetric channel has been proved.With Poisson distribution,the frame syncacquisition probability is obtained and followed by computer simulation.By Markov modelingtechniques,the probability and the mean time into lock mode are given.Finally,it is shown thatthe optimum frame sync method is far superior to conventional,and it is very useful in practice.
基金supported by the National Natural Science Foundation of China(Nos.5113200 and 411027403)the National Special Science Research Program of China(Nos.2010CB923203 and 2011CB808105)the Shanghai Municipal Science and Technology Commission(Nos.11JC1403500 and 10PJ1403400)
文摘Enhancing the photoluminescence and depressing the background emission are important problems in rare earth ion-doped materials. In this letter, the two-photon absorption （TPA） probability in a Pr3＋ ion system is enhanced by a factor of 12.3 by a π-phase step scanning of ultrashort laser pulses. This level is significantly higher than that achieved by a transform-limit pulse. However, the laser intensity of shaped pulse is reduced to 37% of the initial transform-limited pulse. In this method, the TPA probability can also be reduced to 58%. Furthermore, the el＇feet of the shift of the intermediate energy level and the bandwidth of final states on TPA probability is discussed.
