808nm vs 650nm

[zxn474l]

I realize that lasers have a specific wave length but each wave length seems to have unique properties too...so having said that I have a 650nm 200mw red dilda that I really like and it can focus to a fine PIN POINT but power is still power! It seems that 808nm diodes are cheaper to buy and stronger in power usually, so I have seen "you tube" videos of 808nm IR lasers and they burn well but will they focus to such a small pin point spot like the red 650nm red lasers? Also if they can will they have a "burning range" like the reds as long as you can manually focus them using a glass collimating lens instaed of a "fixed" point? Is there any formuls that yield temperature of a laser at a given power output if it is focused as small as it can be focused? I saw a video of a 808nm laser at a couple of watts and the maker of the video said at a few watts...I think 2 watts maybe the "farenhiet" temp. was 1100 degrees... is that about right? and does temp. change with wave lengths at the same power outout? Say 1 Watt red 650nm vs 808nm 1 Watt I.R.? PLEASE RESPOND if you can answer accuratetly. THANKS!

 

[ElektroFreak]

Other than visibility, there will be little difference between the two. They're not very far apart in the spectrum.. As far as equations and formulae go, you could check the RP photonics link in my signature. There may be some info there.

 

[c4r0]

808nm light has a bit less focusing ability, the smallest possible point diameter is the same as wavelength or wavelength/2 (don't remember which one). But you wouldn't notice this difference. The problem with focusing 808nm diodes is because they usually has long emmiter (emmitting area 100x1 or 150x1 um). It means that when you focus it you won't get a point but a line. That's why I didn't use a 808nm diode in my laser ploter. You need much more sophisticated optics than a regular spheric lens to focus a 808nm diode light to a point.