Publication

Optical characterization of high numerical aperture microlenses for quality assessment and fabrication process optimization

Publications associées (30)

Application of Fundamental In-Body Radiation Limitations to Practical Design of Antennas for Implantable Bioelectronics

Fundamental in-body limitations on achievable radiation efficiency could provide decision-making assistance to engineers working on antennas for implantable bioelectronics. In this study, proof-of-concept conformal microstrip antennas are proposed based on ...

IEEE2020

Phase resolved characterization of nanoscale features in optical microstructures

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In this study, we apply interferometric microscopy to study the phase, alongside the intensity, of the light field transmitted through a wide variety of samples. Additionally, we conduct those interferometric measurements at different wavelengths within th ...

EPFL2019

Specification of aspherical surfaces used as refractive elements in micro-optical systems

Wilfried Noell, Toralf Scharf, Jeremy Béguelin

The optical performance of refractive plano-convex microlenses is mainly related to the quality of their (a)spherical surface. An efficient tolerancing of this surface is a key step towards the manufacturing of high quality microlenses. However, we demonst ...

SPIE-INT SOC OPTICAL ENGINEERING2019

Leveraging wafer-level manufacturing process limitations to increase large scale fused silica microlens array uniformity

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The wafer-level production of Fused Silica microlens arrays is limited by systematic process non-uniformities. The common molten resist-reflow process with subsequent dry-etching allows for manufacturing of microlens arrays on 200 mm wafers. A thorough pro ...

SPIE-INT SOC OPTICAL ENGINEERING2019

Raman imaging through multimode sapphire fiber

Demetri Psaltis, Christophe Moser, Damien Claude-Marie Loterie, Georgia Konstantinou, Sunan Deng

We report on a sapphire fiber Raman imaging probe's use for challenging applications where access is severely restricted. Small-dimension Raman probes have been developed previously for various clinical applications because they show great capability for d ...

OPTICAL SOC AMER2019

Improvements on the uniformity of large-area microlens arrays in Fused Silica

Wilfried Noell, Toralf Scharf, Jeremy Béguelin, Raoul Kirner

The uniformity of large microlens arrays in Fused Silica is governed by the production process. It comprises photolithographic patterning of a spin-coated layer of photoresist on a 200mm wafer with a molten resist reflow process and subsequent dry etching. ...

OPTICAL SOC AMER2019

Spatial coherence properties of an LED-based illumination system for mask-aligner lithography

Hans Peter Herzig, Wilfried Noell, Toralf Scharf, Johana Bernasconi, Raoul Kirner

A high-power LED-based illumination system has been developed as a replacement for the mercury arc lamps used in mask-aligner lithography. LEDs are arranged in a grid array and placed in the entrance aperture of individual reflectors. Those reflectors decr ...

SPIE2019

High-resolution interference microscopy of binary phase diffractive optical elements

Toralf Scharf, Michail Symeonidis, Dong Cheon Kim

In this work, we apply the high-resolution interference microscopy technique to investigate the intensity and phase of light transmitted through a binary phase element. Using a combination of simulation and experimental results, we identify specific featur ...

2019

A Real-Time Multi-Camera Depth Estimation ASIC with Custom On-Chip Embedded DRAM

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The capability to process high-resolution videos in real-time is becoming more important in a wide variety of applications such as autonomous vehicles, virtual reality or intelligent surveillance systems. The high-accuracy and complex video processing algo ...

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Are Photonic Nanojets Achromatic?

Myun Sik Kim, Toralf Scharf, Michail Symeonidis

In this work we study the evolution of the photonic nanojet (PNJ) phenomenon as the ratio of the sphere's diameter over the illumination wavelength changes, for microspheres with diameters from 2 mu m to 100 mu m. We measure the focal point position by usi ...

SPIE-INT SOC OPTICAL ENGINEERING2019