Diffraction Limit of an Aperture
Calculator of diffraction limit
Parameter Calculation
Program Description
Main Formulas
Reference

1. Laser central wavelength:  nm
2. Laser beam diameter:  mm
3. Focal length of focusing lens:  mm



1. Laser central wavelength:  nm
2. Numerical aperture:  
 
This program is used to calculate the diffraction limit of an aperture.
Function 1: Given the laser wavelength, beam size, and focal length, calculate the diffraction-limited focused spot size.
Function 2: Given the laser wavelength and numerical aperture, calculate the diffraction-limited resolution.
1. Angular radius of the Airy disk:
$$\Delta \theta = \frac{1.22 \lambda}{D}$$
2. Diffraction limit under the Rayleigh criterion:
$${R_{R}} = \frac{0.61\lambda}{NA}$$
3. Diffraction limit under the Abbe criterion:
$${R_{A}} = \frac{0.51\lambda}{NA}$$
where λ is the wavelength of light, D is the beam diameter, and NA is the numerical aperture.
[01] Cai Lizhong et al., Optics, p.218.