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# "Burning Power" unit of measurement please?

#### GooeyGus

##### New member
1W of 405 will have less photons but they will have higher energy.

1W of 1064 will have more photons with lesser energy.

1W is 1W no matter how you slice it, they will both be able to do the same amount of burning provided that each wavelength is absorbed equally by the material

:beer::beer:

#### Meatball

##### New member
Not interested in Watts. Interested in Watt-seconds- Joules. Power does not determine the work done on a material. It is yes, the absorption spectra, and energy density of the beam (which is related to dot size, in W/cm^2). So yes, the number of photons per unit area over time does affect the work. But could you please explain how 405nm light provides less photons than a larger wavelength laser? I would've thought that the smaller wavelength would allow MORE photons to pass over time!

confusion setting in.... :/

#### john_lawson

##### New member
Yea this is why i got me a meter because 100 looks about the same as 200
and 300 about the same as 500 I mean its brighter but if you don't have a meter

#### Meatball

##### New member
I believe that math can indeed solve this. I'm still in contact with Frothy at the moment. We'll need just a bit more time to figure it out for our use. It will be so worth it!

##### New member
Not interested in Watts. Interested in Watt-seconds- Joules. Power does not determine the work done on a material. It is yes, the absorption spectra, and energy density of the beam (which is related to dot size, in W/cm^2). So yes, the number of photons per unit area over time does affect the work. But could you please explain how 405nm light provides less photons than a larger wavelength laser? I would've thought that the smaller wavelength would allow MORE photons to pass over time!

confusion setting in.... :/
Power is power is power. 1W = 1W. You're taking the wrong conclusions from your calculations.

100mW of violet does EXACTLY the same amount of work as 100mW of red or 100mW or IR. EXACTLY the same amount of power, EXACTLY the same amount of energy per time.

Yes, 1 photon of 405nm has more energy than 1 photon of red, and they both have more energy than 1 photon of IR. A laser beam is a collection of photons. Therefore, 100mW of violet light consists of FEWER photons than 100mW of red light. More energy per photon, fewer photons, since the power is exactly the same.

The only difference then in burning ability is the absorption of your target. If absorption is exactly the same, then burning ability is exactly the same too.

So really, to do what you want, you need to calculate the absorption for your target at each specific wavelength. Beyond power and power density (essentially the same, since you're going to get about the same dot size with any color when just using a simple Aixiz lens), NOTHING else about the laser sets burning. Beyond output power, absorption depends on your target.

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#### GooeyGus

##### New member
Power is power is power. 1W = 1W. You're taking the wrong conclusions from your calculations.

100mW of violet does EXACTLY the same amount of work as 100mW of red or 100mW or IR. EXACTLY the same amount of power, EXACTLY the same amount of energy per time.

Yes, 1 photon of 405nm has more energy than 1 photon of red, and they both have more energy than 1 photon of IR. A laser beam is a collection of photons. Therefore, 100mW of violet light consists of FEWER photons than 100mW of red light. More energy per photon, fewer photons, since the power is exactly the same.

The only difference then in burning ability is the absorption of your target. If absorption is exactly the same, then burning ability is exactly the same too.

So really, to do what you want, you need to calculate the absorption for your target at each specific wavelength. Beyond power and power density (essentially the same, since you're going to get about the same dot size with any color when just using a simple Aixiz lens), NOTHING else about the laser sets burning. Beyond output power, absorption depends on your target.
My hero