The following section is the special issue for the Eleventh Finland-Japan Joint Symposium on Optics in Engineering (OIE’15) held on September 1–3, 2015, at Carelicum, Joensuu, Finland. The special section contains 8 papers based on the presentations at the OIE’15. Each paper has been reviewed and accepted under the editorial policy of Optical Review. The total number of papers presented at the symposium was 58 including 2 keynote, 32 invited, and 24 poster papers.

The OIE’15 was organized by the Institute of Photonics of University of Eastern Finland (https://www.uef.fi/photonics). OIE is an international symposium series in optics in engineering that started in Lappeenranta in 1995 and has been held in Tsukuba in 1997, Kajaani 1999, Suita 2001, Saariselkä 2003, Sapporo, 2005, Tampere 2007, Tokyo 2009, Turku 2011, Utsunomiya 2013, and Joensuu 2015.

The aim of the symposium series is to provide a timely forum for presenting latest novel and innovative works on new photonics, technologies and device applications, and to promote the interaction between Finnish and Japanese scientists who are working in the fields of pure and applied optics and photonics.

The next, i.e., the 12th OIE (OIE’17) will be held at Niigata, Japan. We hope that Finnish and Japanese researchers will meet and have valuable scientific discussions at the OIE symposium continuously.

Finally, we sincerely appreciate all the participants in the conference, the organizers, and sponsors.

April 2016

Editors of Special Section

Yoshio Hayasaki

Erik Vartiainen

Takeshi Yasui

Jarkko J. Saarinen

Katsuhiro Ishii