Hey Jerzy, its great to see you're eager to learn, but it seems like the forums is flooded by questions from you recently. Just a personal request but could you please do us a favor and try a bit harder to search the web or these forums for answers to your questions? You'll find the old posts of LPF will more than answer almost all of your questions. That way we can save some of our time and keep the place from getting too cluttered. Thanks!
I was finding a lot of highly technical info on topics like diode lasers and coherence with Googling, so I posted instead. An idea would be to establish stickies with basic info under the General thread with links that use Flashplayer, like the one I got from SenKat_Stonetek.