14 research outputs found
Volume holograms with linear diffraction efficiency relation by (3+1)D printing
We demonstrate the fabrication of volume holograms using 2-photon polymerization with dynamic control of light exposure. We refer to our method as (3+1)D printing. Volume holograms that are recorded by interfering reference and signal beams have a diffraction efficiency relation that is inversely proportional with the square of the number of superimposed holograms. By using (3+1)D printing for fabrication, the refractive index of each voxel is created independently and thus by, digitally filtering the undesired interference terms, the diffraction efficiency is now inversely proportional to the number of multiplexed gratings. We experimentally demonstrated this linear dependence by recording M=50 volume gratings. To the best of our knowledge, this is the first experimental demonstration of distributed volume holograms that overcome the 1/M^2 limit
Media 1: Light induced fluidic waveguide coupling
Originally published in Optics Express on 05 November 2012 (oe-20-S6-A924
Visualization 1: Two-photon imaging through a multimode fiber
Optical sectioning Originally published in Optics Express on 14 December 2015 (oe-23-25-32158
Multicasting Optical Reconfigurable Switch
Artificial Intelligence (AI) demands large data flows within datacenters, heavily relying on multicasting data transfers. As AI models scale, the requirement for high-bandwidth and low-latency networking compounds. The common use of electrical packet switching faces limitations due to its optical-electrical-optical conversion bottleneck. Optical switches, while bandwidth-agnostic and low-latency, suffer from having only unicast or non-scalable multicasting capability. This paper introduces an optical switching technique addressing the scalable multicasting challenge. Our approach enables arbitrarily programmable simultaneous unicast and multicast connectivity, eliminating the need for optical splitters that hinder scalability due to optical power loss. We use phase modulation in multiple planes, tailored to implement any multicast connectivity map. Using phase modulation enables wavelength selectivity on top of spatial selectivity, resulting in an optical switch that implements space-wavelength routing. We conducted simulations and experiments to validate our approach. Our results affirm the concept's feasibility and effectiveness, as a multicasting switch
Wave optical model for tomographic volumetric additive manufacturing
Tomographic Volumetric Additive Manufacturing (TVAM) allows printing of mesoscopic objects within seconds or minutes. Tomographic patterns are illuminated onto a rotating glass vial which contains a photosensitive resin. Current pattern optimization is based on a ray optical assumption which ultimately leads to limited resolution around and varying throughout the volume of the 3D object. In this work, we introduce a rigorous wave-based optical amplitude optimization scheme for TVAM which shows that high-resolution printing is theoretically possible over the full volume. The wave optical optimization approach is based on an efficient angular spectrum method of plane waves with custom written memory efficient gradients and allows for optimization of realistic volumes for TVAM such as or with voxels and 600 angles. Our simulations show that ray-optics start to produce artifacts when the desired features are and below and more importantly, the amplitude modulated TVAM can reach micrometer features when optimizing the patterns using a full wave model
La Lanterne : journal politique quotidien
15 décembre 18821882/12/15 (N2064,A6)
Media 1: Focusing and scanning light through a multimode optical fiber using digital phase conjugation
Originally published in Optics Express on 07 May 2012 (oe-20-10-10583
Nonlinear Processing with Linear Optics
Deep neural networks have achieved remarkable breakthroughs by leveraging multiple layers of data processing to extract hidden representations, albeit at the cost of large electronic computing power. To enhance energy efficiency and speed, the optical implementation of neural networks aims to harness the advantages of optical bandwidth and the energy efficiency of optical interconnections. In the absence of low-power optical nonlinearities, the challenge in the implementation of multilayer optical networks lies in realizing multiple optical layers without resorting to electronic components. In this study, we present a novel framework that uses multiple scattering that is capable of synthesizing programmable linear and nonlinear transformations concurrently at low optical power by leveraging the nonlinear relationship between the scattering potential, represented by data, and the scattered field. Theoretical and experimental investigations show that repeating the data by multiple scattering enables non-linear optical computing at low power continuous wave light
Media 1: Dynamic bending compensation while focusing through a multimode fiber
Originally published in Optics Express on 23 September 2013 (oe-21-19-22504