Reflection at metal vs glass/air boundaries for mirrors

[ZedCar]

I was looking at this webpage:
http://www.ap.smu.ca/demos/index.php?option=com_content&view=article&id=120&Itemid=85

I was wondering, when n2(imag)=0 what would be the merits of using a metal surface and a glass/air boundary (ie internal reflection in a prism) as a mirror surface?

Also, in what situations might it be important to achieve the maximum reflectance possible?

Thank you.

 

[ZedCar]

Is it because the metal keeps grime off the glass?

I think, in a laser cavity, would be one example of this. Are there any other examples?

Thanks

 

[ehild]

Total reflection really produces 100% reflection while the reflection of a metal mirror never reaches 100%.

If you dive below the surface of water and see upward you will see the the world above water in a circle surrounded by the image of the world below the water surface.
Mirage appears because of total reflection.
The enhanced sparkle of diamond crystals is caused by total reflection.

As applications, fibre optics is one of most important. And yes, it happens in the optical cavity of a laser.
It is also used in optical instruments to turn an upside-down image back to normal with a prism or change the direction of light ray without loss.

Waveguides and ATR (attenuated total reflection prisms) are used in some optical methods of material testing.

ehild

 

[ZedCar]

Thank you ehild!