What is the best material for my desired reflectivity?

[rasgar]

I need a good reflecting collimation material that is faily cheap and has a reflectivity of about 95% for both infrared and visible light. I know polished aluminum meets the criteria for the infrared, and the fused silica also works well for the visible spectrum, but I need somthing that can collimate both.

 

[Claude Bile]

This has been posted in the General Physics forums.

https://www.physicsforums.com/showthread.php?t=143323

Claude.

 

[astrokreng]

After researching and considering your desired reflectivity and cost requirements, I would recommend using a dielectric coating on a substrate of either aluminum or fused silica. Dielectric coatings are thin layers of material that can be applied to a surface to enhance its reflectivity. They are commonly used in optical applications for their high reflectivity and durability.

In terms of cost, aluminum is a more affordable option than fused silica. However, fused silica has a higher refractive index and can achieve a higher reflectivity for visible light. By using a dielectric coating on either substrate, you can achieve a reflectivity of 95% for both infrared and visible light.

It is important to note that the exact composition and thickness of the dielectric coating will affect the final reflectivity. Therefore, I recommend consulting with a materials expert or conducting further research to determine the best combination for your specific needs.

In summary, a dielectric coating on either aluminum or fused silica would be the most suitable and cost-effective option for achieving a high reflectivity of 95% for both infrared and visible light.