Register to reply

Percentage excitation

by sciphys1
Tags: excitation, percentage
Share this thread:
sciphys1
#1
Mar19-14, 12:46 PM
P: 2
Hi Everyone,

I am new to this forums. I am not sure where to post but general discussion is a good place. I am trying to figure out a problem:

I have a sample X in gas phase. Say it has an absorption coefficient of 9.895e-18 cm2 molecule-1 @ 532nm. I have a laser pulsed source (say 50 Hz) giving me 532nm light. How does one calculate what energy one needs to excite 5% or any percentage of the sample? The measured power of the pulsed laser is related to the energy by:

E=power/rep.rate

and one can use this to calculate the number of photons N,by

E=Nhc/lambda where lambda is the wavelength (in the example above it is 532nm).

we can also calculate the fluence by measuring the spot size as we focus the laser beam into the sample. I can't figure out how people choose the energy/power from absorption cross section calculations? I am a novice, so need a little help please. Thank you.

sciphys1
Phys.Org News Partner Physics news on Phys.org
New study refines biological evolution model
Fiber optic light pipes in the retina do much more than simple image transfer
Production phase for LSST camera sensors nears
sciphys1
#2
Mar20-14, 07:20 AM
P: 2
anyone please?


Register to reply

Related Discussions
Nuclear Excitation Introductory Physics Homework 5
Percentage uncertainty and percentage difference Introductory Physics Homework 1
Hydrogen Excitation(s) and De-excitation(s) Advanced Physics Homework 1
Percentage uncertainty and percentage error Introductory Physics Homework 1
Excitation of an electron by a photon Introductory Physics Homework 2