We strive to control light

New paper published in Optics and Lasers in Engineering! In this article, we show how the combination of an acousto-optofluidic lens (TAG lens) with pulse illumination enables quantitative phase imaging (QPI) at rates only limited by the camera frame rate. We demonstrate the feasibility  of our approach by measuring different dynamic samples, including an evaporation droplet at rates exceeding 100 phase maps per second. The ease of implementation and tunability of the proposed system opens the door to democratizing QPI in fluid dynamics, histopathology and other fields involving thin transparent samples.

The ICREA Academia program has awarded Dr. Duocastella one of their grants! These awards distinguish the research career of teaching staff working at one of the eight Catalan public universities.

New paper published in Measurement Science and Technology! In this article, in collaboration with the company Sensofar SL, we present an optical system that features a large numerical aperture of 0.3 and a wide field of view (FOV) of 2.9 x 2.9 mm. Such a system is capable of characterizing additively manufactured parts in a single measurement, without the need for lateral stitching to increase the FOV. The proposed system exhibits optical properties that provide facility for large-field, high-resolution measurement of industrially-produced additively manufactured parts.

New paper published in ACS Photonics! In this article, we propose an innovative method for high-speed volumetric light-sheet microscopy. It is based on simultaneously illuminating the sample with a stack of parallel light-sheets created with acousto-optic deflectors. By using an extended depth-of-field detection system, all sample planes appear in focus, and the corresponding information can be acquired in a superimposed single frame. After applying a single-step inversion algorithm, a stack of frames can be decoded into a volumetric image whose signal-to-noise ratio and contrast are greatly enhanced. The method shows promise toward the investigation of fast dynamic sub-cellular processes in thick biological samples.

New paper published in Journal of Colloid and Interface Science in collaboration with the Laboratory of Nanotechnology for precision medicine at IIT. In this article, we show how two-photon polymerization in microfluidic channels is a suitable technique for the continued fabrication of anisotropic micro-particles in the sub-10 µm range. The proposed approach could support the fabrication of micro-hydrogels of well-defined morphology, stiffness, and surface properties for the sustained release of therapeutic agents.

Dr. Duocastella has received an ERC-CoG for his project DEEP!

New paper published in Journal of Physics Photonics. In this article we review the operational principles, optical properties, and recent applications of acousto-optic systems for advanced microscopy, including random-access scanning, ultrafast confocal and multiphoton imaging, and fast inertia-free light-sheet microscopy.

New paper published in Micromachines. In this article we survey the physics, engineering strategies, and recent implementations of photonic nanojets for high-throughput generation of arbitrary nanopatterns, along with applications in optics, electronics, mechanics, and biosensing. An outlook of the potential impact of nanopatterning technologies based on photonic nanojets in several relevant biomedical areas is also provided.

We are happy to be part of Organvision, a technology proposal to image organoids in real-time and label-free. The project has been funded 3.7 million Euros by Horizon 2020 under the prestigious FET Open RIA program. Organvision comprises of 8 partners spread across 5 cities in 4 countries: Norway (Tromso), Germany (Hamburg, Berlin), Italy (Milan), and Spain (Barcelona).

New paper published in Biomedical Optics Express. Here, we developed volumetric Lissajous confocal microscopy to achieve unsurpassed 3D scanning speed with a tunable sampling rate. The system combines an acoustic liquid lens for fast focus translation with a resonant scanning mirror. Accordingly, the excitation beam follows a dynamic Lissajous trajectory enabling sub-millisecond acquisitions of image series containing 3D information at a sub-Nyquist sampling rate. By temporal accumulation and/or advanced interpolation algorithms, the volumetric imaging rate is selectable using a post-processing step at a desired spatiotemporal resolution. We demonstrate multicolor and calcium imaging over volumes of tens of cubic microns with 3D acquisitions speeds of 30 Hz and frame rates up to 5 kHz.

New review paper published in Nature Photonics! In this Review, we survey recent developments in the emerging field of high-speed variable z-focus optical elements, which are driving important innovations in advanced imaging and materials processing applications. Three-dimensional biomedical imaging, high-throughput industrial inspection, advanced spectroscopies, and other optical characterization and materials modification methods have made great strides forward in recent years due to precise and rapid axial control of light. Three state-of-the-art key optical technologies that enable fast z-focus modulation are reviewed, along with a discussion of the implications of the new developments in variable optical elements and their impact on technologically relevant applications.

New paper published in Applied Surface Science. Here, we present a theoretical and experimental study on the effects that film rigidity, elasticity, and plasticity play on laser catapulting. By combining the thermodynamic equations of the laser-generated propulsion force with the theory of thin plate bending, we derived an analytical model that fully describes the list of events responsible for disk ejection. The model is in good agreement with experiments using elastomers, polymers, and metals. A complete printability map based on the film mechanical parameters is reported, which can help to broaden the family of materials suitable for laser additive manufacturing.