This in turn left its mark on the polarization of the next photon, so amplifying the signal.
光子就这样轮流地将它的偏振标记留给下一个光子，因而增强了信号。
2
Because the image of backscattered electron could reveal structure of the mark as well as the surface, we chose the backscattered electron signal to detect the position of the mark.
A form of frequency modulation in which the carrier frequency is shifted between a mark frequency and a space frequency in response to the impressed intelligence signal (frequency-shift keying).