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« on: March 04, 2012, 04:05:26 AM »
Many of the focus lenses used with CO2 and other lasers are of the single element Plano-convex type. As there have been some discussions recently, in various forums, regarding the orientation of these lenses I would like to clarify the situation.
Whilst this type of lens will operate in either direction the focal point will not be as sharply defined unless the convex surface is placed towards the photon source and I have tried to illustrate this point in the following photos. (Please ignore the backscatter from the test lenses as they do not have the customary anti-reflection coatings).
Basically, the tighter the focal point the greater the concentration of photons the greater the power and thus the greater the efficiency.
Tweakie.