You are using a standard microscope with a 0.18 NA 4× objective and switch to a 0.61 NA 40× objective. (Assume the microscope is immersed in air.)
What are the acceptance angles for each (in degrees)?
? 0.18 NA 4× = _____ °
? 0.61 NA 40× = _____°
Solution
The NA is related to the acceptance angle A, which indicates the size of a cone of light that can be accepted by the fibre.
Both numerical aperture and acceptance angle are linked to the refractive index via:
NA = n a Sin(A); where n a is refractive index of air (1.00);
a) 0.81 = 1*Sin(A);
A = 54.095 degrees.
b) 0.61 =1*Sin(A);
A = 37.589 degrees.
.
Seal of Good Local Governance (SGLG) 2024Final.pptx
You are using a standard microscope with a 0-18NA 4 objective and swit.docx
1. You are using a standard microscope with a 0.18 NA 4× objective and switch to a 0.61 NA
40× objective. (Assume the microscope is immersed in air.)
What are the acceptance angles for each (in degrees)?
? 0.18 NA 4× = _____ °
? 0.61 NA 40× = _____°
Solution
The NA is related to the acceptance angle A, which indicates the size of a cone of light that can
be accepted by the fibre.
Both numerical aperture and acceptance angle are linked to the refractive index via:
NA = n a Sin(A); where n a is refractive index of air (1.00);
a) 0.81 = 1*Sin(A);
A = 54.095 degrees.
b) 0.61 =1*Sin(A);
A = 37.589 degrees.
