Picowatts to photons per second
Type a value in pW to get it in photons/s instantly.
1,278,666photons/s
That's 1.28× as bright as a sensitive detector, while a laser pointer is 2,346,195,898× more. That is about 2.123×10⁻¹² µmol of photons a second.
What it means
How many photons?
This counts photons arriving, not photons detected. A detector’s quantum efficiency decides how many of them are actually recorded.
The math
How to convert pW to photons/s
Each photon carries E = hc ÷ λ, so photons per second = watts × λ(nm) ÷ 1.986 × 10⁻¹⁶. The figures below use the wavelength selected above.
Example: 1 pW = 1,278,670 photons/s.
The table below is for Ultraviolet, 254 nm.
Every unit
Your flux in every unit
Tables
pW to photons/s conversion table
| pW | photons/s |
|---|---|
| 1,000 pW | 1.279×10⁹ photons/s |
| 1,000,000 pW | 1.279×10¹² photons/s |
| 1×10⁹ pW | 1.279×10¹⁵ photons/s |
| 1×10¹² pW | 1.279×10¹⁸ photons/s |
| 1×10¹⁵ pW | 1.279×10²¹ photons/s |
| 1×10¹⁶ pW | 1.279×10²² photons/s |
| 1×10¹⁷ pW | 1.279×10²³ photons/s |
| 1×10¹⁸ pW | 1.279×10²⁴ photons/s |
| 1×10²⁰ pW | 1.279×10²⁶ photons/s |
photons/s to pW conversion table
| photons/s | pW |
|---|---|
| 1,000 photons/s | 0.000782065 pW |
| 1,000,000 photons/s | 0.782065 pW |
| 1×10⁹ photons/s | 782.065 pW |
| 1×10¹² photons/s | 782,065 pW |
| 1×10¹⁵ photons/s | 782,065,000 pW |
| 1×10¹⁶ photons/s | 7.821×10⁹ pW |
| 1×10¹⁷ photons/s | 7.821×10¹⁰ pW |
| 1×10¹⁸ photons/s | 7.821×10¹¹ pW |
| 1×10²⁰ photons/s | 7.821×10¹³ pW |
Quick answers
Quick answers
- How many photons/s is 1 pW?
- 1 pW is 1,278,670 photons/s.
- How many photons/s is 10 pW?
- 10 pW is 12,786,700 photons/s.
The units
About these units
Picowatts (pW)
The noise floor of a good photodiode.
Photons per second (photons/s)
The raw count of photons arriving each second.
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