Dr. Khan later worked at different research laboratories in USA, such as General Dynamics, Phil Co. Ford, and General Telephones and Electronics as a Senior Engineering Specialist. His research work was on thin film technology, a very challenging and attractive field for scientists even today. He was then invited to work as a research scientist at NASA Electronics Research Centre in Cambridge, Massachusetts. Later he was transferred to NASA's Moffet Field Laboratories, where he was involved in fundamental research on thin film materials. He was well-respected as a thin film technology expert in the scientific community of his time. He published numerous technical papers in international journals and made presentations in many well-known conferences. His contribution in Handbook of Thin Film Technology, edited by Dr. Andrew Mossel of IBM bears testimony to this fact. After his retirement from NASA, he was involved in acquisition and management of real estate properties.

Dr. Khan was actively involved in philanthropic activities around the globe. He sacrificed his own personal needs to fulfill the needs of his family and others. His mentorship and guidance helped many in their struggle to uplift their socioeconomic status. He considered his responsibility very seriously. He had empathy for anyone who came across him. His family foundation, known as The Khan Family Foundation, through SpaandanB, a US nonprofit organization, has been sponsoring "Imdad-Sitara Khan Scholarship" which provides substantial financial support to meritorious but economically disadvantaged Bangladeshi students to pursue higher education in medical science, engineering and science. His family foundation sponsored JRCASE, and a VLSI (Very Large Scale Integration) R&D Centre at East-West University, Dhaka, Bangladesh. His foundation is also a sponsor of the Jahangirabad Institute of Technology, India. The Khan Family Foundation, is currently working with ORCA-USA (Old Rajshahi Cadets' Association, USA Chapter), to set up 5 kidney dialysis centres at Rajshahi, Kushtia, Bogra Rangpur and Dhaka. His Foundation has also set up a large number of computer learning centres in different parts of Bangladesh.

Dr. Khan passed away on May 7, 2006.