Flat Top distribution by means of 1 array
This optical scheme allows for single MLA of either positive or negative microlenses
Wavelength.......................... | λ | |
Lens pitch............................. | PA | |
Array A focal length............... | fA | |
Lens FL focal length.............. | fL | |
Flat Top size........................ | DFT | |
Fresnel Number.................... | FN | |
 | ||
 | ||
FN < 10 | - severe diffraction effects | |
10 < FN < 50 | - diffraction effects | |
50 < FN < 100 | - acceptable | |
FN > 100 | - 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.