fresnel number การใช้

• The near field can be specified by the Fresnel number, of the optical arrangement.
• Numerical calculation of the integral using the trapezoidal rule or Simpson's rule is not efficient and becomes numerically unstable especially for configurations with large Fresnel number.
• Where \ theta is the maximal angle described by \ theta \ approx a / L, and the same as in the definition of the Fresnel number.
• As the figures explain, the Gaussian pilot beam criterion allows describing the diffractive propagation for all the near / far field approximation cases set by the coarse criterion based on Fresnel number.