The lasers used in some photosensitive components like laser printers can have their output intensity controlled electrically. Due to the drum either picking up toner or not, half tones are often created with a dither pattern than with in-between light intensity.
I don't understand:
Laser modulation change with what settings/parameter (and what math formula is used to make this) to 'print' the right negative image on photosensitive component (called also laser projection) ? what electronic component drive this laser modulation usually ?
What values, frequency is need to have the correct modulation ?
What is a dither pattern and how is made it ?
I imagine that there is a range through which the modulation transfer function can operate, it can not exceed a certain range - this step I am not clear on how it is managed physically.
EDIT: some references connected seems to be Refractive index, Pockels effect & Kerr effect but how you control electric-electronically laser modulation to print correct patterns on photoreceptor belt or drum ?