DVDRW lasers

[Tomcat]

i have decided to go driver free because on advice of my dad ( eletronic genius) i dont need to spend that much on a driver board with batries(no noisy voltage or spikes) i am on £80 a week wage ( advance aprenticeship) and i live on my lonesome fending for myself so iv got like 20£ to spend now on this project and a large supply of laser diodes at work i have enough for a module and lens assembaly ( advice plz) most people is the axixs 5mw nodiode system but im looking for a very coherant beam minimal divergance ( that is the Mrad right?)

im useing 3 1.2v battries useing a 2.8v autoregulator


could anyone tell me the ampages i will need for 200mw

EDIT: i have found a 2.8v auto regulator then i would use 3 1.2v rechargables

[Tomcat]

looked around and done some math.. i have found most people use 500ma max for around 250-300mW of power i will be useing a .47Ohm set risistor and a 6ohm pot this would give me between 47ma to 560ma at 2.8v advice?

i also just worked out shorting the diode stright to a pair of AAs would throw around 1A into my diode ( now i know why it fried)

[Laser Ben]

You can expect about 35-38% efficiency from DVD laser diodes. That being said, 250/0.35=714.2mWinput/2.8V=255.1mA input. I would start with about 150mW output if you want it to last.