Hello,
I am interested about the index of refraction of polyethylene and polypropylene at wavelengths around 178nm. Does anybody know where can I find this data?
Thanks a lot,
Itamar
israelashvili@gmail.com
Hello Itamar,
This site (http://mst-online.nsu.edu/mst/electronic/electronic3.htm) contains material reproduced from the book Engineering Materials Technology which lists the index of refraction as 1.49 for polypropylene and 1.51 for polyethylene. No wavelengths are specified.
This article (http://www.opticsinfobase.org/abstract.cfm?uri=ao-42-3-592) gives the index of refraction of polypropylene as "1.492(15) for the wavelengths between 118.834 and 251.140 μm, for a polypropylene film of 12.71(2)-μm thickness and 0.9049(7) g/cm3 density." Unfortunately this wavelength range is larger than the 178nm which you are interested in.
This site (http://www.filmetrics.com/refractive-index-database/Polyethylene/PE-Polyethene) allows the download of a .txt file which gives the refraction index of polyethylene over various wavelengths.
I checked the book Handbook of Optics which we have on-site, but polypropylene and polyethylene were not listed in the refractive index table.
These resources are what I was able to find with a quick online search. I'm sure a more thorough search of optical and thermal databases would give you more data.
Best regards,
Ian WilliamsLinear Applications EngineerPrecision Analog and Sensing Products
Hello Ian,
Thank you for your detailed answer. I am deeply sorry for my delayed response.
It seems that it is not easy to find information about polypropylene and polyethylene in the 180nm region. I think maybe polypropylene and polyethylene are totally absorbing in this wavelength.
Actually, for my needs, I am not limited to polypropylene or polyethylene. I need a high hydrogen contained material with index of refraction below 1.5 in the 180nm region. Maybe I should use Ethylene tetrafluoroethylene (ETFE) or kapton (http://www2.dupont.com/Photovoltaics/en_US/assets/downloads/pdf/OptPropCPVMatls-Slides.pdf ). Do you know about other possible materials?
Thank you very much for your help,sorry again for my delayed response,
It looks like ETFE or kapton would meet your < 1.5 index of refraction at 180nm requirement, but the document did not provide the IR transmission characteristic over the wavelength range of 4000nm to 8000nm which the TMP006 measures.
Unfortunately I do not have any other knowledge of materials which will meet your index of refraction requirements.
Ian Williams
Thank you very much for your kind help.