1. DTU Fotonik, Technical University of Denmark, Ørsteds Plads, Building 345, DK-2800 Kongens Lyngby, Denmark
2. Department of Engineering, Aarhus University, Finlandsgade 22, 8200 Aarhus N, Denmark
3. NKT Photonics, Blokken 84, DK-3460 Birkerød, Denmark
4. Center for Integrative Petroleum Research, King Fahd University of Petroleum and Minerals, KFUPM Box 5070, Dhahran 31261, Saudi Arabia