Flat Top distribution by means of 2 arrays
This optical scheme allows for 2 positive MLAs or single monolithic 2-array system of positive or negative or both positive and negative microlenses
Wavelength.......................... | λ | |
Lens pitch............................. | PA | |
A2 focal length...................... | fA2 | |
Lens FL focal length.............. | fL | |
Flat Top size........................ | DFT | |
Fresnel Number.................... | FN | |
 | ||
 | ||
FN < 1 | - severe diffraction effects | |
1 < FN < 5 | - diffraction effects | |
5 < FN < 20 | - acceptable | |
FN > 20 | - excellent | |
A rather long focal array, if its fabrication is technologically not appropriate, can be replaced by a monolithic 2-side array of positive or negative (or combination of both) microlenses.