I think you can use it because of high flexibility of shaping and does not absorb such wavelengths.

For more reasons please refer to the link: https://www.gwplastics.com/top/

Best wishes

I think you can use it because of high flexibility of shaping and does not absorb such wavelengths.

For more reasons please refer to the link: https://www.gwplastics.com/top/

Best wishes

Dear Flemming,

Indeed silicone is flexible and thus has a high form factor. That means, it can be easily shaped to a TIR lens. However, even though silicones are rather transparent at 365 nm, they are not completely transparent at 265 nm, i.e. there is somewhat absorption, which is a function of the type of silicone and manufacturer. This absorption leads to material degradation and yellowing. Therefore, I would recommend to stay with inorganic materials, such UV transparent glasss or quartz, if you want to work in the UV-C range.

Success,

Thomas

PS: You may have a look at this article too:

https://www.led-professional.com/resources-1/articles/transparent-material-considerations-for-uv-optics-in-horticultural-lighting-applications

Dear Flemming, silicones rather have UV blocking capability. Shigeo.

Article Ultraviolet (UV) transmittance characteristics of daily disp...

Thanks for answers..

So it seems that for the design I have it would be prudent to try out optical grade silicone..

So I would like to ask if any has knowledge of a silicone mould type that could withstand 265nm with low absorbance and liferange in the range 1000 hours before changing yellowish

Dr. Flemming

https://www.laserfocusworld.com/optics/article/14040094/moldable-optical-silicone-elastomers-spark-creativity-in-led-lighting