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Subject: Extracting refractive indices / Flowmeter
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Date: 01/12/01 at 8:41 AM
Posted by: Hemang Jesrani
What is the best method for extracting refractive indices of thin films of HfO2, Ta2O5, SiO2, TiO2 etc. We have a Leybold L-560 unit with e-b gun and a Perkin Elmer lambda 15 spectrometer.
How much does the oxygen affect the indices? We have a pressure controller installed but the coatings vary at different base pressures say 2x10^-5 mbar and 8x10^-6 mbar. Is it better to use a flowmeter? What flowrate? Should it be fixed or do flowmeters come with controllers?
What is considered a good AR coating for visible region? We have a 4 layer one of Substance 1 and MgF2 taken from Leybold but I have noticed absorption in the coating from time to time.What could be the reason. Is the reflection important or the transmission?
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