Open AccessLow phase noise microwave extraction from femtosecond laser by frequency conversion pair and IF-domain processing
Author(s) -
Yitang Dai,
Qizhuang Cen,
Lei Wang,
Yue Zhou,
Feifei Yin,
Jian Dai,
Jianqiang Li,
Kun Xu
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.031936
Subject(s) - phase noise , femtosecond , optics , materials science , microwave , dbc , laser , relative intensity noise , noise (video) , physics , semiconductor laser theory , quantum mechanics , artificial intelligence , computer science , image (mathematics)
Extraction of a microwave component from a low-time-jitter femtosecond pulse train has been attractive for current generation of spectrally pure microwave. In order to avoid the transfer from the optical amplitude noise to microwave phase noise (AM-PM), we propose to down-convert the target component to intermediate frequency (IF) before the opto-electronic conversion. Due to the much lower carrier frequency, the AM-PM is greatly suppressed. The target is then recovered by up-conversion with the same microwave local oscillation (LO). As long as the time delay of the second LO matches that of the IF carrier, the phase noise of the LO shows no impact on the extraction process. The residual noise of the proposed extraction is analyzed in theory, which is also experimentally demonstrated as averagely around -155 dBc/Hz under offset frequency larger than 1 kHz when 10-GHz tone is extracted from a home-made femtosecond fiber laser. Large tunable extraction from 1 GHz to 10 GHz is also reported.