Hello. My name is Michael. I can help you with your question.
If you are referring to just being behind glass, that's not a problem.
But if you are talking about the laser passing through the glass, if it isn't passing through at exactly 90 degrees to the surface, the beam will refract. The amount it will refract will depend on the refractive index of the glass. You CAN get zero refractive index glass, but I believe it would be fairly expensive. Here's a page where you can find it:
Is that what you are looking for? Do you have any additional questions?
I see that you were able to go to the link that I provided, but I haven't received a rating from you yet. Is there something else I can do for you that will earn a 5 star rating, or do you have all the information you need with that link?
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