Source Diameter (mm):

Lens 1 Diameter (mm):

Lens 1 Focal Length (mm):

Lens 2 Diameter (mm):

Lens 2 Focal Length (mm):

Source to Lens 1 Distance (mm): --     

Lens 1 to Lens 2 Distance (mm): --     

Lens 2 to Spot Diameter Distance (mm): --     

System Length (mm): --     

Spot Diameter (mm): --     

Input Numerical Aperture, NA: --     

Output Numerical Aperture, NA: --     

$$ d_1 = \text{FL}_1 \left[ \frac{D_{\text{Source}} + D_{L_2}}{D_{L_2}} \right] $$

$$ d_2 = \frac{d_1 \, \text{FL}_1}{d_1 - \text{FL}_1} $$

$$ d_3 = \frac{d_2 \, \text{FL}_2}{d_2 - \text{FL}_2} $$

$$ \text{System Length} = d_1 + d_2 + d_3 $$

$$ D_{\text{Spot}} = \frac{D_{L_1} \, \text{FL}_2}{d_2 - \text{FL}_2} $$

$$ \text{NA}_{\text{Input}} = \sin{\left[ \tan^{-1}{\left( \frac{D_{L_1}}{2 d_1} \right)} \right]} $$

$$ \text{NA}_{\text{Output}} = \sin{\left[ \tan^{-1}{\left( \frac{D_{L_2}}{2 d_3} \right)} \right]} $$

d1	Source to Lens 1 Distance
d2	Lens 1 to Lens 2 Distance
d3	Lens 2 to Spot Distance
DL1	Diameter of Lens 1
DL2	Diameter of Lens 2
FL1	Focal Length of Lens 1

FL2	Focal Length of Lens 2
Dsource	Source Diameter
Dspot	Spot Diameter
NAinput	Input Numerical Aperture
NAoutput	Output Numerical Aperture

Description

Mathematically determine how to configure a source and two lenses into a Koehler Illumination setup. Calculator uses the paraxial lens approximation and enables an initial lens selection. Once lenses are selected, EO recommends modeling one's Koehler Illumination setup in optical design software such as Zemax, CodeV, or FRED to analyze and revise as needed. Please note that performance will vary based on source and lens selections.