- #1

Irishdoug

- 102

- 16

- Homework Statement
- I am reading a paper and want to calculate the average power and peak power of the laser they have used in it.

- Relevant Equations
- Pav = Energy*rep.rate / Ppeak = Energy/pulse duration

Hi, I am reading paper that I have to give a quick presentation on. I want to calculate the average power and peak power of the laser used, a Ti:Saphire laser.

I have the wavelength they are lasing at (450nm), the repetition rate 81Mhz and the pulse duration (pulse width) of 100fs.

I have done the following calculation: ##E = \frac{hc}{\lambda} = \frac{6.626x10^{-34}c}{450x10^{-9}} = 5.372x10^{-19}J##

##P_{peak} = \frac{5.372x10^{-19}J}{100x10^{-15}} = 4.417x10^{-6} J/s##

##P_{av} = Energy*Repetition Rate = 5.372x10^{-19}J (81x10^{6}Hz) = 3.6x10^{-11}J = ~0.04nJ/s##

I am unsure as to my calculations as the numbers seem incredibly small. I was expecting mW and W at least. The laser is being used in biophotonics so maybe these low powers are required, but I am unsure as I have no experience in this area. Thankyou.

I have the wavelength they are lasing at (450nm), the repetition rate 81Mhz and the pulse duration (pulse width) of 100fs.

I have done the following calculation: ##E = \frac{hc}{\lambda} = \frac{6.626x10^{-34}c}{450x10^{-9}} = 5.372x10^{-19}J##

##P_{peak} = \frac{5.372x10^{-19}J}{100x10^{-15}} = 4.417x10^{-6} J/s##

##P_{av} = Energy*Repetition Rate = 5.372x10^{-19}J (81x10^{6}Hz) = 3.6x10^{-11}J = ~0.04nJ/s##

I am unsure as to my calculations as the numbers seem incredibly small. I was expecting mW and W at least. The laser is being used in biophotonics so maybe these low powers are required, but I am unsure as I have no experience in this area. Thankyou.