The Portuguese Society for Optics and Photonics is organizing the IV International Conference on Applications in Optics and Photonics, AOP2019, which will be held in Lisbon, Portugal, on May 31 to June 4, 2019. Upon the major success of SPOF’ first three conferences - AOP2011 in Braga (www.optica.pt/aop2011), AOP2014 in Aveiro (www.aop2014.org), and AOP2017 at the University of Algarve in Faro (www.aop2017.org) - it was decided to change the conference periodicity to biennial and therefore this next conference will take place at the University of Lisbon in 2019. With a rich history of over twenty centuries, a delightful atmosphere and welcoming people, Lisbon charms all visitors making their stay an unforgettable one. In the open friendly environment characteristic of SPOF’ conferences, this forum will be an excellent opportunity to further foster the establishment of the widest range of cooperation projects and relationships with colleagues and institutions from Portugal and from all around the world. Open to contributions in all topics of Optics and Photonics and application’ fields, with this conference we expect to review the state-of-the art in these subjects and to foresee and discuss the future of research in Optics and Photonics. A good number of plenary and key lectures by world renowned researchers in all fields of optics and photonics, will mark a varied and exciting scientific program. We expect to have boots and presentations of research labs and industries in order to promote and facilitate the setting-up of future new collaborations. A special space will be reserved for photonics spin-offs and young companies and entrepreneurs. As it is tradition in our AOP conferences an enjoyable social program will be organized further contributing to the setting up and cementing of long lasting friendship and cooperation relationships. Important dates Abstract Submission Deadline: January 18, 2019 Notification of Acceptance: February 22, 2019 Early Registration Deadline: March 15, 2019 Full Paper Submission: April 30, 2019 www.aop2019.org aop2019@optica.pt