Lisa Ackermann: Changing the color of a shaped laser beam
In several recent publications, Lisa Ackermann reported her progress on laser beam shaping using spatial light modulators (SLMs). Now she adds another interesting piece of work as she was able to change the color of the shaped light in situ. In her publication “Polarization‑controlled nonlinear computer‑generated holography”, she describes a setup where infrared light hits the SLM for initial beam-shaping. Subsequently, it passes a color-changing non-linear crystal and is up-converted resulting in a color change to green.
This is particularly exciting as it opens the path to shape ultra violet (UV) light, which usually is not shaped but absorbed by an SLM: using color up-conversion, visible light can first be shaped and then changed in color to reach the UV region. This is of special interest since UV radiation is of high importance in laser materials processing.