Controllable photonic crystal with periodic Raman gain in a coherent atomic medium Zhang, Zhaoyang ; Feng, Jingliang ; Liu, Xing ; Sheng, Jiteng ; Zhang, Yiqi ; Zhang, Yanpeng ; Xiao, Min Abstract Publication: Optics Letters Pub Date: February 2018 DOI: 10.1364/OL.43.000919 Bibcode: 2018OptL...43..919Z