Lasing action in two-dimensional organic photonic crystal lasers with hexagonal symmetry

• Published in: Applied physics. B, Lasers and optics Vol. 82; no. 4; pp. 539 - 541
• Main Authors: FORBERICH, K, DIEM, M, CREWETT, J, LEMMER, U, GOMBERT, A, BUSCH, K
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01-03-2006
• Subjects: Emission; Exact sciences and technology; Fluorescence; Fundamental areas of phenomenology (including applications); Laser materials; Lasers; Lasing; Optical materials; Optics; Photonic bandgap materials; Photonic crystal lasers; Photonic crystals; Physics; Surface chemistry; Symmetry; Two dimensional; Thin films; Semiconductor lasers; Feedback; Surface emitting lasers; Two dimensional structure; Optical activity; Fluorescence; Laser materials; Laser modes; Optical materials; Photonic crystal lasers
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-005-2120-y

We investigate fluorescence and lasing action from strongly modulated two-dimensional surface relief structures with hexagonal symmetry onto which thin films of optically active organic material have been deposited. As compared with second-order laser structures with square symmetry, these organic photonic crystal lasers exhibit unusual feedback mechanisms. As a result, we observe surface-emitting lasing action with a central beam normal to the surface and a hexagonal emission pattern of side-beams whose direction slightly deviates from the normal. A corresponding theoretical analysis allows us to determine the photonic bandstructure and the low-threshold laser modes in this system. These results agree very well with fluorescence data and confirm the hexagonal lasing pattern and the corresponding emission angles.