#Steve-Mould #video on hand-drawn #holograms #toread
on 02026-08-11#Holograms made with a pen plotter following Bill Beaty’s approach.
on 02026-08-11#Applied-Science #video on using Cloudray’s GM-100 US$7000 100-watt MOPA laser to engrave diffraction patterns (LIPS: laser-induced periodic structuring) and near-holograms on stainless steel with LightBurn. “MOPA” is “master oscillator power amplifier” and gives you a lot of control over the pulse power waveform from a fiber laser. He holds his too-thin stainless-steel sheets down with an aluminum vacuum chuck to get repeatable focusing, which doubles as a heatspreader and a heatsink. 300mm/s and 300kHz, thus 1μm pitch, worked well to get diffraction gratings, which he thinks are made of varying-thickness oxide layers changing the phase delay. He was using 45ns pulses at 19.6% power. He tried making optical #holograms: “How could you not do it after you realize you have full pitch and angle control over a #diffraction grating?”.
on 02025-10-15