Ex medical ophthalmic (eye) class IV laser Nd:YAG 3W 20ms 15J, Q switched 12ns 0.2J with HeNe 0.1 mW. It weighs 400 kg including a solid pallet.
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It is vintage 1988 but is now serviced and functioning at 1/3 power (5 J pulse) with the old lamp. I have a new one but am not game to install it yet. The Zeiss binocular optics for the slit lamp are amazing. The aiming HeNe laser is used to focus as well.
The control panel and complete unit.
Rear view, capacitor bank and front panel
The 3 laser head components with output to the right.
The slit lamp and aiming He-Ne laser and a view of standard 2 mm newspaper print.
My laser goggles.
The dark green ones made by Yamamoto have an OD of 6 at the Nd:YAG wavelength of 1064nm. I don’t want any unintended laser eye surgery done on me! The red goggles are supposedly UK army surplus but sold cheap as a fashion item. They are however, very effective for the green laser making it almost invisible as shown in a photo earlier on this page.
I have now got it running such that it can burn holes in paper and even leave small pits in metal. The focused beam will leave a hole in paper much smaller than a newsprint full stop. More pictures soon.
The rated power of the Q switched 0.2 J at 20 nS is an instantaneous power of 100 megawatts. It is enough to ionise air when focussed.
Above: I visited the ophthalmologist today (as a patient but took along my YAG goggles and camera as you do). This photo shows air ionization from a Q switched ophthalmic laser (theirs) which is a more modern version of mine above and is also a Q-switched Nd:YAG running at 1064nm in the infrared. It was firing 8 millijoule pulse trains of up to 8 pulses. At the point of focus a small spot of ionization appeared in mid air 6 inches away from the output lens and about 2 inches in front of my hand but being an out of focus point in free air there is no reference to place it. My hand was needed for focus as sadly the autofocus on my camera is not up to nanosecond pulses. It was a tiny bright bluish white point like an electrical spark.
This photo makes it look larger than it is. The net result looks like someone has put a blue dot in the picture using MS Paint. Honest I didn’t. There is some motion blur of the laser assembly as we tried to fire a second shot in a different position in the same exposure.
This group uses air ionization to make 3D images.
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Photo date : 2005