Formulae (4)

Question 1

Near Field

Answer 1

NF = D² / 4λ

or

NF = D²f / 4V

Question 2

Angle of Beam Spread at 10% intensity

Answer 2

sin0 = 1.08λ / D

or

sin0 = 1.08V / fD

Question 3

Angle of Beam Spread at 50% intensity

Answer 3

sin0 = 0.56λ / D

or

sin0 = 0.56V / fD

Question 4

Theoretical Angle of Spread (Angle Beam at 100% intensity)

Answer 4

sin0 = 1.22λ / D

or

sin0 + 1.22V / fD