Laser diodes - J8Y4M4C

[The_Doctor]

He says they can get up to 300mw if they are "properly heat sinked" but I think he forgot "in Antarctica"

Ahhh dry humor... ...

Pulsed. Might get CW to match a pulse rating with SHORT life, and only if there is headroom. There isn't though, those are ABSOLUTE MAX ratings according to Mitsubishi, who made them. Laser data sheets are notoriously short on detail, but trust what's there first, then your own experience. I'd never buy from a listing that did not even tell me the make and part code let alone offer a data sheet somehow. And I'd never sell one that way either.

[mliptack]

Right, but wouldn't the diode operate pulsed at 300mw, even if it is not properly heat sinked? The pulse length would just be shorter correct?

[The_Doctor]

Sure, but there's not much point to it. The average is what matters if you want to do it for show. Most are rated for 50% pulse width ratio at around 1 MHz, though they are often stated as pulse lengths and ratios from which you can deduce a maximum repeat rate. Some are only rated for 40% on times, you have to be careful to read the figures right. In practise, it's VERY unlikely you'll get any more brightness than with well chosen CW drive current, and CW drives are far easier to build too.

Got to sleep, I posted a lot now, and it's 03:16 here now...

[mliptack]

Heh, we're fighting for the same point here lol, I think I just worded my post weird. But yeah I am well aware we are looking for the CW value, since pulsed isn't much use to us...

Yeah, it's getting a bit late here now too... :/ oh well, PL is more interesting then most dreams I have ever had. And plus theres always some light so I walk towards it, but it's not an Arctos unit (or Vari-lite for that matter)... so I'm not really interested so I turn back around

[The_Doctor]

There was some talk a few years ago of pulsing making eyes more sensitive to the beam, especially when it is scanned. I think that was for low power diodes though where it might make a difference if eye sensitivity tails off at low powers, or ambient light noise makes it hard to see. Not sure if there's much point even there, but it IS a cool effect if you can see the dotted beam. Most showmakers want to avoid it but I can imagine it being useful at times, as the dot intensity could be double what the CW beam can do safely. Might just be enough to give a display an edge in the presence of other bright sources. The main problem with that is that the useful range of pulse lengths and rates puts the diode into CW rating conditions, much slower than the nanoseconds usually specified for pulses.