You can consider the use of perfluoronated polymers. An example I came across is CYTOP from AGC. It has high transmittance >200 nm, especially the grade made especially for high UV transmittance. Dirk Renckens Chem Eng PhD Candidate Delft University of Technology -----Original Message----- From: kamlesh_engg@iitb.ac.in [mailto:kamlesh_engg@iitb.ac.in] Sent: 25 March 2009 07:28 To: mems-talk@memsnet.org Subject: [mems-talk] polymer which has transmission in UV Hi i am using SU8 polymer for optical waveguide but it has very high absorbance in UV region (280nm). I want to use 280nm wavelength for my optical waveguide. Can someone suggest any polymer which has good transmission at 280nm and can be used for fabrication. -- Kamlesh Pawar M.Tech (Biomedical Engg) Mob :+919870062960 IIT-Bombay