Concave mirror is a concave optical glass lens plated with protected metalic coating or dielectric coating on the curved surface. The substrate is generally BK7, K9, B270 or Fused Silica Glass.
 

As all we know, there are four coating options for a mirror. How to select the most ideal one? Here're our opinions for this issue as bellow:
 

1. For visible full-reflevtion, we strongly recommend dielectric coating. Especially a single wavelength in the range of 400-700nm, we could offer an excellent reflectivity up to 99.7%.
 

2. Protected Aluminum coating is widely used for 400-700nm visible spectrum, but it delivers a low relflection around 90%. However if you are about to operate a wide range without strictly reflection, Aluminum is a cost-efficient choice.
 

3. Silver coating has better reflectivity than Aluminum, could make a reflectivity more than 98% at a wide range, even at SWIR (2000nm).
 

4. As for Gold coating, it's more expensive. Also, offers higher reflectivity than other matal coating. It's widely used in high power laser system which needs less energy loss.
 

Any further questions, please feel free to contact our sales engineer  

More size and shape is available. If we have stock, sample is also OK.