6th gen fighters

originally posted by: anzha
a reply to: pteridine

ok. I gotta stop this meme here. Reflective coatings have been tested already by the USAF against continuous wave lasers. They don't work. They even tried the spinning cylinder trick. Again. Doesn't work.

The reasons are multiple.

1. The mirrors are almost never perfect. Pits from sand, dust, etc or even dust, water, etc that stick to the skin of a reflector will convey heat. CW lasers are about conveying as much heat energy into the target as possible to cause the target to melt, cook off, catch fire, etc. Pulsed lasers are about evaporating a thin layer on the target to cause shock damage through a mini explosion. They are actually pretty stunning for what they do.

2. The mirrors have to be set for VERY specific wavelengths to work even close to perfectly: the mirrors for the laser in the beam director (or pointer tracker system), are meant for that wavelength. You don't get it exactly right - assuming a monochromatic laser - and you get heat dumped into you. Oops. You tune for one laser and a different one will get you easily.

3. Lasers are not monochromatic. Ideally, yes. Reality, no. They have a peak energy at a particular wavelength, but also deposit energy in lesser amounts in other wavelengths. This mucks with targets, too.

Its actually better to have something like the shuttle tiles that can take lots of heat and then get out of the way of the laser with your remaining eye. ahem.

Source: Me. I used to work on high energy lasers at white sands.

What is the optical cavity in such lasers made of, and how do you change the peak energy wavelength?