6 research outputs found
Additive manufacturing of solid diffractive optical elements via near index matching
Diffractive optical elements (DOEs) have a wide range of applications in
optics and photonics, thanks to their capability to perform complex wavefront
shaping in a compact form. However, widespread applicability of DOEs is still
limited, because existing fabrication methods are cumbersome and expensive.
Here, we present a simple and cost-effective fabrication approach for solid,
high-performance DOEs. The method is based on conjugating two nearly refractive
index-matched solidifiable transparent materials. The index matching allows for
extreme scaling up of the elements in the axial dimension, which enables simple
fabrication of a template using commercially available 3D printing at
tens-of-micrometer resolution. We demonstrated the approach by fabricating and
using DOEs serving as microlens arrays, vortex plates, including for highly
sensitive applications such as vector beam generation and super-resolution
microscopy using MINSTED, and phase-masks for three-dimensional single-molecule
localization microscopy. Beyond the advantage of making DOEs widely accessible
by drastically simplifying their production, the method also overcomes
difficulties faced by existing methods in fabricating highly complex elements,
such as high-order vortex plates, and spectrum-encoding phase masks for
microscopy
Supplementary document for Monocular Kilometer-Scale Passive Ranging by Point-Spread Function Engineering - 6036580.pdf
Supplemental documen
3D printable diffractive optical elements by liquid immersion
Diffractive optical elements (DOEs) are used to shape the wavefront of incident light. This can be used to generate practically any pattern of interest, albeit with varying efficiency. A fundamental challenge associated with DOEs comes from the nanoscale-precision requirements for their fabrication. Here we demonstrate a method to controllably scale up the relevant feature dimensions of a device from tens-of-nanometers to tens-of-microns by immersing the DOEs in a near-index-matched solution. This makes it possible to utilize modern 3D-printing technologies for fabrication, thereby significantly simplifying the production of DOEs and decreasing costs by orders of magnitude, without hindering performance. We demonstrate the tunability of our design for varying experimental conditions, and the suitability of this approach to ultrasensitive applications by localizing the 3D positions of single molecules in cells using our microscale fabricated optical element to modify the point-spread-function (PSF) of a microscope
Programmable thermocapillary shaping of thin liquid films
We present a method that leverages projected light patterns as a mechanism
for freeform deformations of a thin liquid film via the thermocapillary effect.
We developed a closed-form solution for the inverse problem of the thin-film
evolution equation, allowing to obtain the projection pattern required in order
to achieve a desired topography. We experimentally implement the method using a
computer controlled light projector, which illuminates any desired pattern onto
the bottom of a fluidic chamber patterned with heat absorbing metal pads. The
resulting heat map induces surface tension gradients in the liquid-air
interface, giving rise to thermocapillary flow that deforms the liquid surface.
If a polymer is used for the liquid film, it can then be photocured to yield a
solid device. Based on the inverse problem solutions and using this system, we
demonstrate the fabrication of several diffractive optical elements (DOEs),
including phase masks for extended depth of field imaging, and for 3D
localization microscopy. The entire process, from projection to solidification,
is completed in less than five minutes, and yields a sub-nanometric surface
quality without any post-processing.Comment: Manuscript and supplementary information combine
Near index matching enables solid diffractive optical element fabrication via additive manufacturing
Abstract Diffractive optical elements (DOEs) have a wide range of applications in optics and photonics, thanks to their capability to perform complex wavefront shaping in a compact form. However, widespread applicability of DOEs is still limited, because existing fabrication methods are cumbersome and expensive. Here, we present a simple and cost-effective fabrication approach for solid, high-performance DOEs. The method is based on conjugating two nearly refractive index-matched solidifiable transparent materials. The index matching allows for extreme scaling up of the elements in the axial dimension, which enables simple fabrication of a template using commercially available 3D printing at tens-of-micrometer resolution. We demonstrated the approach by fabricating and using DOEs serving as microlens arrays, vortex plates, including for highly sensitive applications such as vector beam generation and super-resolution microscopy using MINSTED, and phase-masks for three-dimensional single-molecule localization microscopy. Beyond the advantage of making DOEs widely accessible by drastically simplifying their production, the method also overcomes difficulties faced by existing methods in fabricating highly complex elements, such as high-order vortex plates, and spectrum-encoding phase masks for microscopy