Phys.org April 22, 2023
Specifically tailored refractive index of light modifications, directly manufactured inside glass using a short pulsed laser, enable an almost arbitrary control of the light flow. However, the stringent requirements for quantitative knowledge of these modifications, as well as for fabrication precision, have so far prevented the fabrication of light-efficient aperiodic photonic volume elements (APVEs). An international team of researchers (Austria, Germany, UK) has developed a powerful approach to the design and manufacturing of light-efficient APVEs. They optimized application-specific three-dimensional arrangements of hundreds of thousands of microscopic voxels and manufactured them using femtosecond direct laser writing inside millimeter-sized glass volumes and achieved diffraction efficiencies up to 80%, which was enabled by precise voxel characterization and adaptive optics during fabrication. According to the researchers their approach is not limited to borosilicate glass but is potentially extendable to other substrates, including birefringent and nonlinear materials, giving a preview of even broader functionalities, including polarization modulation and dynamic elements… read more. Open Access TECHNICAL ARTICLE
The intensity shaper can convert an input Gaussian beam to precisely direct light… Credit: Advanced Photonics Nexus, Vol. 2, Issue 3, 036006 (April 2023