RT Journal T1 Laser-written three dimensional nonlinear photonic crystals A1 Feng CHEN PB Front. Optoelectron. FD 2019-12-15 YR 2019 JF Frontiers of Optoelectronics JO Front. Optoelectron. VO 12 IS 4 SP 342 DO 10.1007/s12200-019-0982-6 K1 LK {https://journal.hep.com.cn/foe/EN/article/article_26366.shtml}