BEGIN:VCALENDAR VERSION:2.0 PRODID:-//linuxsoftware.nz//NONSGML Joyous v1.4//EN BEGIN:VEVENT SUMMARY:Microstructured Grayscale Optics with Direct Laser Writing for Str uctured Light DTSTART:20260625T100000Z DTEND:20260625T120000Z DTSTAMP:20260623T162934Z UID:ddec152c-8a14-43b8-a584-f4d6a4ef2f24 SEQUENCE:2 CREATED:20260623T104230Z DESCRIPTION:This thesis develops a platform for the fabrication of diffrac tive optical elements in fused silica for structured light generation in h igh-energy ultrafast regimes. For this purpose\, a direct laser writing gr ayscale lithography process\, followed by inductively coupled plasma react ive ion etching transfer into fused silica\, was established. Different bl azed diffractive axicons were fabricated to be used in ultrafast two-dimen sional spectroscopy (27 μm- period)\, synthetic motion experiments (27 μ m- period)\, and light spring (spatio-temporal beams) generation for laser -plasma interaction (9 and 12 μm- period)\, the latter using a narrowband 1030 nm laser.The fabrication process optimization included the AZ 1518 p hotoresist dose-height curve calibration\, the selection of the developmen t time\, and the use of a temporary thermoplastic adhesive layer during et ch transfer\, to limit photoresist thermal degradation. The axicons were c haracterized by profilometry\, scanning electron microscopy\, and first-or der diffraction efficiency measurements. The axicons with a period of 27 μm achieved efficiencies of 62.6% and 65%\, whereas the more demanding pe riods of 9 and 12 μm achieved 29.9% and 38.2%\, respectively. This reduct ion reflects the increased flattening and top rounding of the axicons' \; blazed profiles observed at smaller periods.A spatiospectral hologram m atched to the axicon with period of 12 μm was fabricated with a transferr ed silica depth of 2.22 μm\, close to the 2.29 μm target for full 2π ph ase modulation\, at 1030 nm. This work establishes the optical architectur e required for future light spring generation and spatio-temporal characte rization\, using a system in fused silica scalable towards high-energy str uctured light applications. LAST-MODIFIED:20260623T104239Z LOCATION:Sala V1.01 (Piso 1 do Pavilhão de Civil) do IST URL:http://df.vps.tecnico.ulisboa.pt/pt/eventos/microstructured-grayscale- optics-with-direct-laser-writing-for-structured-light/ X-ALT-DESC;FMTTYPE=text/html:

This thesis develop s a platform for the fabrication of diffractive optical elements in fused silica for structured light generation in high-energy ultrafast regimes. F or this purpose\, a direct laser writing grayscale lithography process\, f ollowed by inductively coupled plasma reactive ion etching transfer into f used silica\, was established. Different blazed diffractive axicons were f abricated to be used in ultrafast two-dimensional spectroscopy (27 μm- pe riod)\, synthetic motion experiments (27 μm- period)\, and light spring ( spatio-temporal beams) generation for laser-plasma interaction (9 and 12 μm- period)\, the latter using a narrowband 1030 nm laser.

The f abrication process optimization included the AZ 1518 photoresist dose-heig ht curve calibration\, the selection of the development time\, and the use of a temporary thermoplastic adhesive layer during etch transfer\, to lim it photoresist thermal degradation. The axicons were characterized by prof ilometry\, scanning electron microscopy\, and first-order diffraction effi ciency measurements.

The axicons with a period of 27 μm achieve d efficiencies of 62.6% and 65%\, whereas the more demanding periods of 9 and 12 μm achieved 29.9% and 38.2%\, respectively. This reduction reflect s the increased flattening and top rounding of the axicons'\; blazed p rofiles observed at smaller periods.



A spatiospectral h ologram matched to the axicon with period of 12 μm was fabricated with a transferred silica depth of 2.22 μm\, close to the 2.29 μm target for fu ll 2π phase modulation\, at 1030 nm. This work establishes the optical ar chitecture required for future light spring generation and spatio-temporal characterization\, using a system in fused silica scalable towards high-e nergy structured light applications.

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