Authors: Wilm, Tobias; Wieland, Max; Fiess, Reinhold & Stork, Wilhelm
Abstract: “We present highly transparent, wave front printed volume holographic optical elements (vHOEs), realized with a new recording method based on the pre-illumination of incoherent light patterns. The introduced amplitudemodulated pattern illuminates a distinct area on the unexposed, photopolymer-based holographic recording material prior to the hologram recording sequence. The incoherent pre-illumination scheme enables a precise tuning of the material’s local photosensitivity without the formation of a holographic volume diraction grating. As a consequence, the pre-illumination exposure signicantly suppresses the formation of transparency diminishing structures in the material that are formed concurrently with the volume diraction grating during the hologram recording sequence. The pre-illumination component is integrated in an extended immersion-based wave front printing setup, which realizes vHOEs by sequentially recording single holographic elements in an array-like structure. A wide range of dierent recording congurations is enabled by our recording setup due to independent modulation of both wave fronts and the possibility to realize large o-axis recording angles. We introduce two hologram characterization methods, based on a diraction eciency and a slanted-edge method analysis, which are used to evaluate the implemented pre-illumination method and demonstrate signicant improvements to the see-through quality of the presented wave front recorded vHOEs.”
Restricted Access
Publication: Proc. SPIE 12445
Issue/Year: Proc. SPIE 12445, Practical Holography XXXVII: Displays, Materials, and Applications, 124450S, 2023
Authors:Reza Esmaeilzadeh, Jamasp Jhabvala, Lucas Schlenger, Mathijs van der Meer, Eric Boillat, Cyril Cayron, Amir Mohammad Jamili, Junfeng Xiao, and Roland E. Logé
Toward Architected Microstructures Using Advanced Laser Beam Shaping in Laser Powder Bed Fusion of Ti-6Al-4V
Authors:Kuznetsov, A. G., Munkueva, Z. E., Dostovalov, A. V., Kokhanovskiy, A. Y., Elizarova, P. A., Nemov, I. N., Revyakin, A. A., Kharenko, D. S., & Babin, S. A.
Random Raman Lasing in Diode-Pumped Multi-Mode Graded-Index Fiber with Femtosecond Laser-Inscribed Random Refractive Index Structures of Various Shapes