A new FFT algorithm has been deduced, which is called the base-6 FFT algorithm. The amount for calculating the DFT of complex sequence of N =2 r by the base-6 FFT algorithm is M r( N )=14/3· N log 6 N -4 N +4 for...A new FFT algorithm has been deduced, which is called the base-6 FFT algorithm. The amount for calculating the DFT of complex sequence of N =2 r by the base-6 FFT algorithm is M r( N )=14/3· N log 6 N -4 N +4 for multiplication operation of real number and A r( N )=23/3· N log 6 N -2 N +2 for addition operation of real number. The amount for calculating the DFT of real sequence is a half of it with the complex sequence.展开更多
The shift mechanism of Bragg wavelength with stress variation for a fiber grating is investigated in detail. The influence of strain change on reflection and bandpass is theoretically analyzed. By applying stress, the...The shift mechanism of Bragg wavelength with stress variation for a fiber grating is investigated in detail. The influence of strain change on reflection and bandpass is theoretically analyzed. By applying stress, the dynamic single/dual channel filter with tunable fiber Bragg gratings is achieved.展开更多
文摘A new FFT algorithm has been deduced, which is called the base-6 FFT algorithm. The amount for calculating the DFT of complex sequence of N =2 r by the base-6 FFT algorithm is M r( N )=14/3· N log 6 N -4 N +4 for multiplication operation of real number and A r( N )=23/3· N log 6 N -2 N +2 for addition operation of real number. The amount for calculating the DFT of real sequence is a half of it with the complex sequence.
文摘The shift mechanism of Bragg wavelength with stress variation for a fiber grating is investigated in detail. The influence of strain change on reflection and bandpass is theoretically analyzed. By applying stress, the dynamic single/dual channel filter with tunable fiber Bragg gratings is achieved.
