In theory - no. In practice, some lasing can be obtained with CO2 and air (nitrogen). Optimal performance is obtained using 10% CO2, 20% N2, and 70% He. There's a big difference between this and a commercial laser, in terms of performance for it's size. For me personally, homemade lasers are more interesting than commercial ones. To each his own. I've seen some truly amazing work with commerical tubes/lasers. Some folks, more than I, are inclined towards theory and electronics.
@magx1 cool, and is that just regular aluminium first surfaced mirror? also, i am currently designing a co2 laser, and i like to build things from scratch cos its cheep and more fun. so instead of a glass neon or xenon tube (i want the glass so i can see the cool purple colour :P and i cant find any neon tubes) do you think i could use clear glass beer bottles, cut open and either expoxied or, if i can get a blow torch, braised together to make my laser tube? or will it be too fat?
@rbneville You can get away with a lot if you just want a working laser. In fact, it's really more fun when you do it as much as possible from scratch. It's obviously easier (if not altogether necessary) to get good performance with a proper ZnSe output coupler.
With my examples, the beam spreads more than with ZnSe. It's passing through a hole and non-polished salt window, so this isn't surprising.
@magx1 I am saving up for a small vacuum vapor deposition system and i was thinking about masking off a dot in the center before coating the mirror with Al then after coating just remove the masking. Do you think that would work?
@rbneville You must have a hole in the glass. The CO2 laser wavelength will not pass through glass. This is the purpose of using the rock salt window over the hole: rock salt is the only common substance I know of that is transparent to 10.6 microns.
Pretty ingenious with using rock salt for an output coupler. I never thought a regular mirror would have enough reflectiveness so i read to work in a co2 laser. well, how bout that it does.instead of O rings optics could be placed flat against both ends regular optics that is and epoxied into place. I like what you have come up with I was going to build a home made model myself but I bought one off ebay I use now a sealed unit. good luck
@bg0821 It's been done before. Rock salt optics are also used in spectroscopy, for mid-IR range wavelengths and beyond. An ordinay mirror will work only because CO2 lasers have high gain relative to other common CW gas lasers. An O-ring between a fixed plate and a movable plate is necessary. It permits movement required for adjusting and aligning the mirrors. The laser will not work unless the mirrors are aligned. O-rings also make an air-tight seal.
@magx1 I wonder why adjustment would be needed when lets say like with sealed laser tubes the optics are affixed permanently in place and epoxy would give an air tight seal if used under the edges of the optic and then placed down on a flat surface.
@bg0821 The mirrors on commercially manufactured laser tubes must also be aligned. If not, the laser will not work. The difference is that big companies mass produce tubes as part of a very precise and controlled process. The mirrors are both permanently mounted and aligned as part of that process. But proper alignment is always necessary. To be practical, a homemade laser tube needs adjustable mirrors. I'm not saying it's impossible, but you cannot just stick mirrors on the ends of a tube ...
@magx1 ...and approximate everything by eye. Once permanently locked in place, you could not correct or alter mirror alignment if they later became misaligned due to shock or impact. Besides this, you might later want to experiment with different types of mirrors. You will probably also need to replace the salt window from time to time, as the surface quality of salt windows slowly degrade due to the absorption of moisture.
You say rocksalt, would ordinary table salt work as well or this is the same? How do you make the salt window?
dtiydr 6 months ago
Put your hand infront of it and let us see!! lol
169Phoenix 6 months ago
looks like a giant ear plug for james bond.. new gadget maybe?
sil0o 6 months ago
a laser full of pure co2 will work? nicely?
chilidress 6 months ago
@chilidress
In theory - no. In practice, some lasing can be obtained with CO2 and air (nitrogen). Optimal performance is obtained using 10% CO2, 20% N2, and 70% He. There's a big difference between this and a commercial laser, in terms of performance for it's size. For me personally, homemade lasers are more interesting than commercial ones. To each his own. I've seen some truly amazing work with commerical tubes/lasers. Some folks, more than I, are inclined towards theory and electronics.
magx1 6 months ago
@magx1 cool, and is that just regular aluminium first surfaced mirror? also, i am currently designing a co2 laser, and i like to build things from scratch cos its cheep and more fun. so instead of a glass neon or xenon tube (i want the glass so i can see the cool purple colour :P and i cant find any neon tubes) do you think i could use clear glass beer bottles, cut open and either expoxied or, if i can get a blow torch, braised together to make my laser tube? or will it be too fat?
Lachieh923 5 months ago
Man you saved me alot of worry. i had been thinking about using a mirror with a hole in it instead of Zinc mirrors, but i wasnt sure if it would work
rbneville 1 year ago
@rbneville You can get away with a lot if you just want a working laser. In fact, it's really more fun when you do it as much as possible from scratch. It's obviously easier (if not altogether necessary) to get good performance with a proper ZnSe output coupler.
With my examples, the beam spreads more than with ZnSe. It's passing through a hole and non-polished salt window, so this isn't surprising.
magx1 1 year ago
@magx1 I am saving up for a small vacuum vapor deposition system and i was thinking about masking off a dot in the center before coating the mirror with Al then after coating just remove the masking. Do you think that would work?
rbneville 1 year ago
@rbneville You must have a hole in the glass. The CO2 laser wavelength will not pass through glass. This is the purpose of using the rock salt window over the hole: rock salt is the only common substance I know of that is transparent to 10.6 microns.
magx1 1 year ago
Pretty ingenious with using rock salt for an output coupler. I never thought a regular mirror would have enough reflectiveness so i read to work in a co2 laser. well, how bout that it does.instead of O rings optics could be placed flat against both ends regular optics that is and epoxied into place. I like what you have come up with I was going to build a home made model myself but I bought one off ebay I use now a sealed unit. good luck
bg0821 1 year ago
@bg0821 It's been done before. Rock salt optics are also used in spectroscopy, for mid-IR range wavelengths and beyond. An ordinay mirror will work only because CO2 lasers have high gain relative to other common CW gas lasers. An O-ring between a fixed plate and a movable plate is necessary. It permits movement required for adjusting and aligning the mirrors. The laser will not work unless the mirrors are aligned. O-rings also make an air-tight seal.
Thank you for your comments
magx1 1 year ago
@magx1 I wonder why adjustment would be needed when lets say like with sealed laser tubes the optics are affixed permanently in place and epoxy would give an air tight seal if used under the edges of the optic and then placed down on a flat surface.
bg0821 1 year ago
@bg0821 The mirrors on commercially manufactured laser tubes must also be aligned. If not, the laser will not work. The difference is that big companies mass produce tubes as part of a very precise and controlled process. The mirrors are both permanently mounted and aligned as part of that process. But proper alignment is always necessary. To be practical, a homemade laser tube needs adjustable mirrors. I'm not saying it's impossible, but you cannot just stick mirrors on the ends of a tube ...
magx1 1 year ago
@magx1 ...and approximate everything by eye. Once permanently locked in place, you could not correct or alter mirror alignment if they later became misaligned due to shock or impact. Besides this, you might later want to experiment with different types of mirrors. You will probably also need to replace the salt window from time to time, as the surface quality of salt windows slowly degrade due to the absorption of moisture.
magx1 1 year ago