Noob who is lazy!!

Hi guys, apologies if this has been covered in another thread (if it has, please point it out to me).

I've always been interested in lasers. I own a 100mW green laser pointer and actually work with 400-500w pulsed YAG lasers as I'm a quality engineer that works for a company that makes 3D metal laser printers.

I'd like to build a powerful 2-5watt laser. I'm not bothered about colour, I just want something that burns shit! I really don't want to buy pre-made boards etc as I want a project I can work on from scratch, so does anyone have physical plans, circuit diagrams and links to buy the right diodes and components? I already have 2 x 2500mAh batteries from a dual taser I made so I'd like something I could use those with. I'm also fine using multiple diodes. I don't mind spending up to £100 or around $150 for my American friends.

Any suggestions?