Co2 laser Mirrors 101. everything you wanted to know but were afraid to ask.

American Photonics talks about the 4 different types of Co2 laser mirrors

[@SarbarMultimedia]

Let me add a few facts Material Thermal conductivity Thermal expansion (low is poor conductor) (low is little expansion) Glass 1 6 Molybdenum 139 5 Copper 400 16 Silicon 3 4 Using a worst case 2% percentage power loss per mirror for a 100 watt laser beam ie 2 watts.Let's take a look at how such heating will affect each material. The thermal conductivity of glass and silcon are both in the same region of poor and thus for the same amount of energy input they will heat up quicker than metal mirrors but with relatively low expansion rates they both will be mechanically stable. It is true that copper has 4 times the expansion rate of silicon but it is also 133 times better at dissipating 2 watts and will never suffer as much expansion as the silicon. Molybdenum is similar expansion to silicon but 45 times better at dissipating 2 watts, so even less distortion there. Neither glass nor silicon are natural reflectors .The get their reflective properties from higly reflective gold plating. Damage that gold surface, even with micro porosity, and the substrate will rapidly heat up. That risk is nil with metal mirrors. Pure copper mirrors are not available because of the supposed oxidation propensity.Thus they are gold coated to deal with this percieved problem Micro porosity of the coating will not affect its reflectve properties and will not cause it to heat up any faster. Compare the cost of each mirror type with it's strengths and weaknesses and you will see why most machines (as mentioned in the video) are supplied with molybdenum mirrors.

[@VladOnEarth]

Hi Russ, again was checking what mirrors are the best and of course saw you here! :D Going with Molybdenum just like you suggested, it all makes sense. And i totally agree that copper wont suffer thermal expansion from absorbing 1.5 watts of laser energy, as it dissipates it nearly instantly, and if you have a more powerful tube you can always stick a round heatsink in the back just like I did. I personally disliked copper a lot being in Florida and working in my garage, it oxidizes horribly and very fast, scratch super easy and they are pricey. So I am not gonna use it again for these reasons.

[@srirajrajaram5733]

Thank you. I learned a lot. You have a customer in me

[@PatrickHillPhotography]

Thanks for the info

[@ebersalcido8810]

This was great

[@ragcell]

Setting aside potential damage from the heat of a laser beam, what is the best way to _clean_ mirrors and laser lenses? Anytime one physically touches a lens, there is a risk of scratching the surface and / or damaging the lens / mirror coating. While alcohol seems to be the preferred solvent because it is readily and inexpensively available and does dissolve oily contaminants to which lasering debris (smoke, etc., from whatever is being lasered). Do vapors from acrylic, “laserable” resins in laminate (Formica), etc., degrade lens surfaces? Additionally, if the cotton swab does not absorb / adsorb everything, it will just smear oily contaminants over the surface of the lens, and if a small, harder piece of debris is between the cotton swab and the lens, the lens will get scratched. Smearing an oily substance over the surface of the glass just helps floating or airborne debris to adhere more easily to the lens surface. So, one solution is to use an ultrasonic bath to “pop off” the contaminants, especially oily substances, from the lens surface. Keep in mind the only thing physically touching the mirror or lens surface is liquid, water with a very small amount of some surfactant to ‘grab’ contaminates, particularly solid debris. So, my basic question, does / can ultrasonic cavitation (cleaning) damage lens coatings, that are generally electrostatically bonded to lens and mirrors? Some suggest using acetone; this is a pretty potent solvent. However, while it does clean lenses and mirrors better than alcohol, there is still the problem of rubbing the surface of lenses and mirrors with a cotton swab. Additionally, many lenses and mirrors are held in place with epoxy (or whatever) to lens tubes. Acetone would most certainly dissolve or degrade (most) bonding agents - and other non-metal components. So again, what is the best way to clean lenses and mirrors, particularly if the lens is embedded deep (2¾± inches) inside a ¾" lens tube? There is very little, as in almost no, wiggle room to clean the lens. Most laser machines now have their lenses “enclosed” in a metal tube or housing that precludes a lot of debris from getting on the lens in the first place, still the lenses and mirrors in these seemingly well sealed lens assemblies still get dirty.

[@VladOnEarth]

just invest in overpowered exhaust fan and thank me later. I burn not only acrylic, but even rubber and mirrors are always super clean. My head mirror is sealed though.

[@muserbellamy1140]

Thankyou for your help how do I determine the diameter I need thanks

[@senthilkumar-fy1cq]

Thank you for your help, which mirror is a suitable LiDAR sensor, I am using this sensor buy.garmin.com/en-US/US/p/557294#specs,please help me to find a mirror, I don't know about mirror so.

[@robertbogan7557]

Has anyone tried wearing them? 😎🥸? I was wondering if a lazer mirror could concentrate light for passive night vision? Kind of like how cat eyes reflect light.