The 4th Laser and Optoelectronics Conference (LOC 2018) will be held from December 1-3, 2018 in Sanya, China. This Conference will cover issues on Laser and Optoelectronics. LOC 2018 is sponsored by Engineering Information Institute, Open Access Library, Scientific Research Publishing, and 1000thinktank. It dedicates to creating a stage for exchanging the latest research results and sharing the advanced research methods.