I'm trying to compare some figures of power for continuous wave vs. pulsed lasers.(adsbygoogle = window.adsbygoogle || []).push({});

I have a known application which uses pulsed nitrogen lasers (λ = 337.1nm, such as this one) to produce fluences of ~20-200Jm^-2 and pulse widths on the order of ~2ns to produce irradiance figures of roughly 10^11 Wm^-2.

I would like to see how close I can get to these figures of power using an InGaN laser diode (even though I understand these types of laser are generally much less powerful). If I have a multiquantum well InGaN laser (λ =405nm, a blu-ray player laser), with an output power of1-2.5Wand a pulse width of (as low as)60 ps, spot sizes on the order of 0.3-0.5μm, and repetition rates of20-80 MHz, what is the maximum power I could produce from this setup?

When I do the math as I understand it, I get

power = 1 J/s (W)

spot size = (0.363E-6m)2

Irradiance = 7.754820E6 J/m2·s (Wm^-2)

I get a little lost when incorporating the pulse width. How do I calculate fluence (Jm^-2) from these figures? Even if the diode laser is a CW laser can I get more power from it by pulsing it at 60ps pulse widths? Does pulsing a CW laser yield any possibility of a power boost? Would there be any other conceivable means of increasing the power of the InGaN laser?

Any help on this calculation and any help on understanding the benefits/downsides of pulsing a CW laser is much appreciated!

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# Comparing power ratings between CW and pulsed laser

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