title: Comment on "Uncertainty relation for photons".
authors.affiliation: School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054, China. zywang@uestc.edu.cn
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Wang
authors.forename: Cai-Dong
authors.initials: CD
authors.lastname: Xiong
authors.forename: Qi
authors.initials: Q
authors.lastname: Qiu