DISCLAIMER: I’m not responsable for what you’re doing! It’s dangerous and may be not successful if you’re not paying enough attention. If you have any questions regarding this topic, feel free to ask!
In today’s experiment to manipulate lights character, such as amplitude and phase, using a spatial light modulator has become a common method to change the properties of a ligthfield to individual needs.
By generating digital hologramms and displaying them on a digital output such as an LCoS (Liquid Crystal on silicon) or a DMD (Digital Mirror Device) it can change an incomming wave in phase and amplitude. As an example it’s possible to generate multiple laser spots in the focus of an microscope objective, to generate optical tweezers which can trap particles in the scale of a few microns (link). Another application of thes SLMs are adaptive optics, to compensate optical aberrations in the optical path, by writing the inverse of the deformed wavefront.