Theory

So today was a bit of slow day here at LOA, my project's not quite ready for me despite how ready I might be. We're mostly just setting up the lab, but I can't really be trusted with the equipment cause I have no idea what it does so I mostly just help in whatever small way I can. Anyway, I thought it'd be helpful to go into a bit of the theory of my measurement for my sake. So here goes. When a laser as powerful as the lasers we're dealing with hits a solid object it immediately creates a plasma. You might be asking yourself, "self, what's a plasma?" Well hold on, I'll explain. It's the fourth state of matter. Not enough? Yeah I didn't get it after that either. Basically it's a state of matter where all the particles are ionized. You can think of it as almost a jello-like structure with layers of negative charge/positive charge,      

(delicious and plasma-y)

and when you push on one side of the jello, the forces between the charge particles cause them to oscillate  which is a fancy word for jiggle, in this case. (This metaphor brought to you by the Letter J, for John Nees) So when the laser hits the solid object, ion jello is made because of the energy of the light. Now if this plasma is dense enough, it will act as a mirror more or less, causing the light to be reflected, and also transferring energy to the light. The natural reaction for things with energy imparted to them is for them to speed up. (Think kicking a soccer ball). However light is the speed limit for the universe, and unlike road speed limits, you can't surpass it. So the light cannot speed up. What it does do is speed up its frequency. So say the light was traveling roughly with a frequency of 10^-15 s or a femtosecond, which creates this plasma, and is thus reflected off of it. It would leave with a frequency of 10^-18 s. Or an attosecond (abbreviated as).

What my mission, should I choose to accept it (which I already have I suppose), is to help create a machine that will emit attosecond pulses of light.

"In the time of chimpanzees, I was a monkey."
-Beck