Enter the optical power that propagates away from grating and the optical power incident on the grating into the calculator to determine the Diffraction Efficiency. 

Diffraction Efficiency Formula

The following formula is used to calculate the Diffraction Efficiency. 

Ediff = Pm / Pinc *100

  • Where Ediff is the Diffraction Efficiency (%)
  • Pm is the optical power that propagates away from grating 
  • Pinc is the optical power incident on the grating 

How to Calculate Diffraction Efficiency?

The following two example problems outline how to calculate the Diffraction Efficiency.

Example Problem #1:

  1. First, determine the optical power that propagates away from grating. In this example, the optical power that propagates away from grating is given as 50.
  2. Next, determine the optical power incident on the grating. For this problem, the optical power incident on the grating is given as 70.
  3. Finally, calculate the Diffraction Efficiency using the equation above: 

Ediff = Pm / Pinc *100

Inserting the values from above and solving the equation: 

Ediff =50 / 70 *100 = 71.14 (%)


Example Problem #2: 

Using the same process as above, first define the variables required by the formula. In this case, these values are:

optical power that propagates away from grating = 30

optical power incident on the grating = 80

Entering these values yields:

Ediff = 30/ 80 *100 = 37.5 (%)