Bounce mirror question

[dilbert]

Daft newbie question but want to be 100% sure before I glue these....

When using a broadband glass hr mirror for a bounce in a projector the beam is not passed through the actual glass is it? I.E the glass part gets glued to the mount & the beam is bounced off the 'back' of the mirror.

[allthatwhichis]

Correct; kinda. You should be using a first surface mirror, meaning the glass side is actually the back. If you bounce it through the glass you will get a double reflection which is not what you want.

[Solarfire]

Daft newbie question but want to be 100% sure before I glue these....

When using a broadband glass hr mirror for a bounce in a projector the beam is not passed through the actual glass is it? I.E the glass part gets glued to the mount & the beam is bounced off the 'back' of the mirror.

No you don't want the beam going thru the glass and these mirrors are usually called first surface mirrors. Sending the beam thru the glass will cause distortions, ghost beams or interferences due to a part of the beam being reflected on the surface of the glass and the rest of the beam reflecting on the actuall reflective surface on the back side of the glass. The beam will even ping pong within the glass like an echo with several beam instances leaving the glass with a steady reduction in power

cheers!

[dilbert]

Thanks a lot guys, that's what I thought - just wanted to be sure!