| 09.1996- | Associate Research Professor, |
| | Physics Department, |
| | Carnegie Mellon University, |
| | Pittsburgh,
Pennsylvania,
USA. |
| 11.1992-08-1996 | Associate Research Scientist, |
| | Center for Astrophysical Sciences, |
| | Johns Hopkins University, |
| | Baltimore,
Maryland,
USA. |
| 03.1992-10.1992 | Research Associate,
|
| | Medium Deep Survey, |
| | NASA/
AURA/
Space Telescope Science Institute, |
| | Baltimore,
Maryland,
USA. |
| 03.1991-02.1992 | Visiting Senior Research Associate, |
| | Institute Fundamental Studies, |
| | Hantana, Kandy,
Sri Lanka. |
| 01.1989-02.1991 | Research Associate, |
| | National Research Council, |
| | NASA/
GSFC/
Astronomy Data Center, |
| | Greenbelt,
Maryland,
USA. |
| 09.1986-12.1988 | Research Associate,
|
| | National Research Council, |
| | HIA/
Dominion Astrophysical Observatory, |
| | Victoria,
British Columbia,
Canada. |
| 01.1984-08.1986 | Member, |
| | School of Natural Sciences, |
| | Institute for Advanced Study, |
| | Princeton,
New Jersey,
USA. |
| 09.1978-04.1979 | Teaching Assistant, |
| | Department of Physics and Astronomy, |
| | University of Pittsburgh, |
| | Pittsburgh,
Pennsylvania,
USA. |
| 04.1976-06.1978 | Assistant Lecturer, |
| | Department of Physics, |
| | University of Sri Lanka,
Colombo Campus, |
| | Cinnamon Gardens, Colombo,
Sri Lanka. |