Different algorithms are used to demodulate the interference
signal detected by PD and the demodulation results are shown
in Fig. 5. From Fig. 5 (a), demodulation result based onPGC-DCM algorithm is unstable and varying with LID signal.
The LID exits and deteriorates the demodulation result. From
Fig. 5 (b), demodulation result based on PGC-Arctan algorithm
has steady amplitude. The LID is greatly suppressed. However,
the wave shape of the result has obviously distortion due to
harmonic distortion. From Fig. 5 (c), demodulation result based
on our improved PGC algorithm has highly steady amplitude,
furthermore, it does not exist harmonic distortion.