title: Operation bandwidth optimization of photonic differentiators.
abstract: We theoretically investigate the operation bandwidth limitation of the photonic differentiator including the upper limitation, which is restrained by the device operation bandwidth and the lower limitation, which is restrained by the energy efficiency (EE) and detecting noise level. Taking the silicon photonic crystal L3 nano-cavity (PCN) as an example, for the first time, we experimentally demonstrate that the lower limitation of the operation bandwidth does exist and differentiators with different bandwidths have significantly different acceptable pulse width range of input signals, which are consistent to the theoretical prediction. Furthermore, we put forward a novel photonic differentiator scheme employing cascaded PCNs with different Q factors, which is likely to expand the operation bandwidth range of photonic differentiator dramatically.
authors.forename: Siqi
authors.initials: S
authors.lastname: Yan
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jianji
authors.initials: J
authors.lastname: Dong
authors.forename: Aoling
authors.initials: A
authors.lastname: Zheng
authors.forename: Shasha
authors.initials: S
authors.lastname: Liao
authors.forename: Hailong
authors.initials: H
authors.lastname: Zhou
authors.forename: Zhao
authors.initials: Z
authors.lastname: Wu
authors.forename: Jinsong
authors.initials: J
authors.lastname: Xia
authors.forename: Xinliang
authors.initials: X
authors.lastname: Zhang