[1] Dept. of Elec. and Electron. Eng., University of Hong Kong, Hong Kong, Pokfulam Road
[2] London University, University College
[3] Cambridge University, Robinson College
[4] Kirsten Aeronautical Laboratory, Seattle, WA
[5] K. K. Engineering, Co., Hong Kong
[6] Micro Systems, Hong Kong
[7] National Ion Implantation Facility, Department of EEE, University of Surrey
[8] Optoelectronics Team, Department of EEE