question about light absorption

Thread Starter

kkhh

Joined Jan 2, 2013
1
. The absorption coefficient for GaAs at λ = 633 nm is α = 3×10^6m-1
. Find, what percentage of the incident light will pass through the layer, the thickness of which is:
1) 200 nm; 2) 500 nm; 3) 1 µm; 4) 2 µm; 5) 10 µm;
i have tried solving the question but didn't find it in the materials
i have found I=I0exp(-ax)
where a is absorption cofficient and x s the thickness

thank you very much
 

GopherT

Joined Nov 23, 2012
8,009
Beer Lambert law,
A=abc

a=your molar extinction co-efficient
b=thickness of sample
c= concentration

Since concentration is always constant, set it equal to 1. Your co-efficient is in micrometers so re-adjust all sample thicknesses to micrometers.
 

WBahn

Joined Mar 31, 2012
30,045
. The absorption coefficient for GaAs at λ = 633 nm is α = 3×10^6m-1
. Find, what percentage of the incident light will pass through the layer, the thickness of which is:
1) 200 nm; 2) 500 nm; 3) 1 µm; 4) 2 µm; 5) 10 µm;
i have tried solving the question but didn't find it in the materials
i have found I=I0exp(-ax)
where a is absorption cofficient and x s the thickness

thank you very much
Q1) This should be in the Homework Help section.

Q2) What are your attempts to answer the question?

Q3) What does I=Io*exp(-ax) tell you?

Q4) What are you looking for?

Q5) What is the difference between the answers to Q3 and Q4?
 
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