Lisa Ackermann: Changing the color of a shaped laser beam

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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 Polarizationcontrolled nonlinear computergenerated 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.

Infrared laser light is shaped to form a snowflake (left), or guided through the non-linear crystal beforehand, resulting in a green snowflake (right)

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.

Lisa Ackermann works at the Institute of Photonic Technologies, her supervisor is Michael Schmidt. The original publications can be found in Scientific Reports.

Light hits the non-linear crystal.