12x diodes from Sanyo and Nichia

[chipdouglas]

somebody correct me if i am wrong..... I thought you get the highest power reading straight from the LD die with out a lens. and a good lens will will let you keep as much of that power as possible?

 

[Meatball]

correct.

 

[nikokapo]

Just wondering ..... but, probably, cause they don't worth the efforts, for the same amount of delivered power.

I mean, a "pulsed" driver, can give to the diode the double (or more, depend from the duty cycle you choose) of the current, and you can take the double of the power, but just for the half of the duty cycle, so the final energy delivered to the target point is the same.

Basically, is the same principle that is used for led's, where they drive them at the double (or more) of the power for 50% duty cycle, and the retinal persistence of our eyes give you the impression that they emit more light ..... but, if i emit , as example, 1 watt CW (that means 1 watt/second energy), and i double the power and half the cycle, like 2 Watt for half second, then half second off, i still have 1 watt/second energy at target point ..... i tried, using a high power led, rated for 1 A CW, drived it with a mosfet switch at 10A for 1 mS, with 9 mS off time (that is a 10% duty cycle), and it looks at least 4 or 5 times more bright at bare eyes (but on a camera, no difference, ccd's have not the same persistence effect of our retina) ..... but the current total was still 1A, and the total energy was still the same, only the impression on the eyes, is that the led is much more bright

btw, this is the same reason for which i don't trust to these blue (not blu-rays) lasers, sold at certain declared power, and having pulsed drivers (you can see if a driver is pulsed moving the dot quickly on a surface, if you see it as a -------- line, instead a continuous line, the driver is pulsed ..... and, maybe, the power is less than the declared )

I know, I had to build a remote controller for a project in 4th year in secondary school...I'll never forget
I had to pulse the diode so I could get a higher power for bursts because I needed a longer range.

If we got pulsed drivers we could improve visibility, the pulse could be over 1000Hz if we wanted, but I don't know how laser diodes take it. I know the final power would be the same for BURNING but for regular pointing it could be a great innovation (in the DIY community) since we could get at least 1/3 more out of the diodes.

 

[HIMNL9]

I think that, if the output stage is well designed, with clear and sharp wave fronts, the diodes don't suffer for the pulsed operation ..... after all, in a 20X dvd burner, the diode is usually drived pulsed at almost 2 MHz, so it must be safe to use it also at 100 KHz with a mosfet-driver pulsed unit .....

let me do some experiments with that, i just have a phr diode that is starting to go weak (i probably fried it a little bit, testing it 24/7 for 3 weeks at 120mA ) ..... can use it and see if there's some difference in visibility, between CW and pulsed modes (but need a pair of days ..... real world pretend that i work for pay bills, too )