Current absorption and beam measurement

[hozone]

Hello,
a simple question.
If i measure the laser beam of a diode that absorbs 100mW current, what value should i read.
I mean, i suppose there is some power loss between current absorption and light emission, isn's so?
Thanks!!

 

[Alaskan]

What kind of laser? Green 532nm, 520nm, or other? A Osram TB450B is advertised to have 29-30 percent efficiency but is a fairly high power blue laser diode. Any idea what kind of diode is used in it?

 

[The Lightning Stalker]

It could be anything. Every diode is different.

 

[Alaskan]

If it is a 532nm laser pointer pumped with an IR diode it would be difficult to tell you as you have the efficiency of the IR diode itself and then the efficiency of the conversion to 532nm green on top of that and lens loss too.

If it is a 532nm laser pointer drawing 100 milliamps of current (is that what you meant, or milliwatts of power?) at 2 volts that would be about 200 milliwatts of IR power and you could get 20, 30, 40 or so mw of 532nm out of it, I suppose, along with 25 percent infrared you can't see too.... efficiencies can vary greatly from laser pointer to laser pointer if 532nm.

If 520nm or any of the non IR pumped diodes the efficiency is much easier to figure to tell you what the approx. output might be, within reason.

 

[hozone]

I'm sorry but i forgot to tell you the diode type.
For the specific question is a red 635mW one, do not know the model.
Anyway this question is pretty generic.
Speaking in general terms, non IR diode, has more or less 30 percent efficiency. It means that if a diode absorbs 100mW, it should output 30mW. Right?
And also I suppose this is not linear efficency.
Tks

 

[The Lightning Stalker]

If you need to know the power output of a
diode, you should get an LPM. The LaserBee
is pretty good and will measure anything up
to 3.7W, depending on the model.

 

[hozone]

I've a cheap LPM, a DIY TEC based.
Calibrated on a 20mW laser.
I'm asking this question even because, trying the 300mW absorbtion red laser I'm reading 120mW on my LPM. It makes sense if the efficenciy is almost 30%. Unfortunately this LPM is the only one I've, so i can not be sure about my readings.
Tks for help!