Today 03/05/10 I did a quick experiment to measure that how much intensity we might have to cut down to snap the beam profile without saturating ccd. It turned out to be roughly 1e-7W, if input is 1W. Later I explored the possibility of using multiple reflections to cut down the intensity. It turned out that 1 plane glass strip cut down the intensity 10%. So 7 consecutively reflection will cut down the intensity up to roughly 1e-7. BUT each reflections contain 2 reflections out of two surfaces (I used 1mm thick), so total 14 REFLECTIONS. If use just an ultra thin may be a glass membrane carefully with one or two NDs than this can be done and beam profile might still be preserved. Still working……
I emailed Mr. Gunn on 03/04/10, about profiling the beam at higher powers, and waiting for his reply.