Lien SmeestersVrije Universiteit Brussel | VUB · Applied Physics and Photonics (TONA)
Lien Smeesters
Doctor in Photonics Engineering
About
34
Publications
3,931
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124
Citations
Citations since 2017
Introduction
Lien Smeesters is a postdoctoral researcher at the Vrije Universiteit Brussel, within the B-PHOT Brussels Photonics research team. Her main expertise is situated in the field of optical design and optical spectroscopy (UV-VIS-NIR absorption spectroscopy and fluorescence spectroscopy). Her research related to optical design covers both the design of imaging, illumination and light-collection systems. Her expertise related optical spectroscopy mainly covers UV-VIS-NIR absorption spectroscopy and fluorescence spectroscopy. Generally, Lien focuses on multidisciplinary and applied-oriented research. She is actively involved in several research projects in collaboration with industry.
Additional affiliations
January 2017 - present
Education
August 2012 - December 2016
September 2010 - June 2012
September 2007 - July 2010
Publications
Publications (34)
Sustainably using resources, while reducing the use of chemicals, is of major importance in agriculture, including turfgrass monitoring. Today, crop monitoring often uses camera-based drone sensing, offering an accurate evaluation but typically requiring a technical operator. To enable autonomous and continuous monitoring, we propose a novel five-c...
Wide field-of-view imaging optics offer a huge potential for space-based Earth observation enabling the capture of global data. Reflective imaging telescopes are often favored, as they do not show chromatic aberrations and are less susceptible to radiation darkening than their refractive counterparts. However, the main drawback of reflective telesc...
We report on a near-infrared imaging spectrometer for sensing the three most prominent greenhouse gases in the atmosphere (water vapor, carbon dioxide and methane). The optical design of the spectrometer involves freeform optics, which enables achieving exceptional performance and allows progressing well beyond the state-of-the-art in terms of comp...
Acknowledgements to Reviewers
The Editors of the Journal of Food Engineering would like to thank the following subject matter experts for their support to scientific publishing through peer reviews of multiple manuscripts that they have performed for the journal in 2021. Without the generous support of these professionals. Journal of Food Engineer...
We present the development of a compact (about 1.3 × 2.0 × 20 mm3) freeform optical lightguide for sensing applications, from the conceptual design to the fabrication through injection molding. The design of the optic is based on the flow-line method from Nonimaging Optics, which allows the desired optical functionalities (45° half-acceptance and 4...
The measurement of the Earth’s Outgoing Longwave Radiation plays a key role in climate change monitoring. This measurement requires a compact wide-field-of-view camera, covering the 8–14 µm wavelength range, which is not commercially available. Therefore, we present a novel thermal wide-field-of-view camera optimized for space applications, featuri...
Acrylamide formation is nowadays one of the major concerns of the potato-processing agriculture industry. We investigate the use of broadband reflection spectroscopy (400 – 1700 nm), in combination with machine learning, to optically classify raw potatoes inducing different levels of acrylamide after frying, covering concentrations between 200 ppb...
Near-infrared spectroscopic data, used for non-destructive product identification, are traditionally processed using multivariate data analysis techniques. However, these methods often cover only a limited product variability. We target the development of a novel machine learning based algorithm enabling the identification of foreign objects, in co...
We present a freeform lightguide comprising two 2D flow-line concentrators to achieve 45° acceptance angle in 3D, under particularly strict mechanical constraints. The design has been optimized for injection molding fabrication.
We report on the conceptual design of a new wide field-of-view shortwave camera, for measuring Earth’s reflected solar radiation. The camera comprises a commercial-off-the-shelf CMOS sensor, and a custom-designed wide field-of-view lens system with an opening angle of 140°. The estimated effective nadir resolution is 2.2 km. The simulated stand-alo...
Climate on Earth is determined by the Earth Radiation Budget (ERB), which quantifies the incoming and outgoing radiative energy fluxes. The ERB can be monitored by non-scanning wide field-of-view radiometers, or by scanning narrow field-of-view radiometers. We propose an enhanced design for the wide field-of-view radiometer, with as key features th...
Food quality and food safety are gaining the past decades more and more importance. In particular application domains such as the identification of foreign bodies in solid food streams, the quality screening of vegetables and fruits, the recognition of food products inducing a health risk and the monitoring of the quality and authentication of liqu...
The presence of mycotoxins in food products is a major worldwide problem. Nowadays, mycotoxins can only be detected by the use of sample-based chemical analyses. Therefore, we demonstrate the use of one- and two-photon-induced fluorescence spectroscopy for the non-destructive detection of mycotoxins in unprocessed food products. We first explain ou...
The formation of acrylamide during the frying of potatoes is nowadays one of the major concerns of the potato-processing agriculture industry. Much research has been carried out to identify the acrylamide precursors in raw potatoes in order to minimize its formation during frying. Raw potatoes that give rise to an excess of acrylamide can currently...
Laser metal deposition is an additive manufacturing process that allows the production of near net shape structures. Moreover, the process can also be applied for the addition of material to an existing component for repair. In order to obtain structures with reproducible and excellent material properties, it is necessary to understand the thermal...
Deoxynivalenol is one of the most abundant contaminants in crops worldwide. Its presence in food and feed products causes health risks and induces economic losses. To date, deoxynivalenol is mostly detected by sample-based, time-consuming chemical analyses. To obtain a non-destructive detection of deoxynivalenol in unprocessed, solid maize kernels,...
The presence of carcinogenic aflatoxins in food and feed products is a major worldwide problem. To date, the aflatoxin contamination can only be detected by the use of destructive sample-based chemical analyses. Therefore, we developed an optical setup able to detect the localized aflatoxin contamination in individual maize kernels, on the basis of...
Presenting state-of-the-art research into the dynamic field of tunable micro-optics, this is the first book to provide a comprehensive survey covering a varied range of topics including novel materials, actuation concepts and new imaging systems in optics. Internationally renowned researchers present a diverse range of chapters on cutting-edge mate...
The presence of aflatoxins in food and feed products is considered as one of the most important food safety problems in the world. Aflatoxins occur in a wide range of food products and can cause serious health risks. Moreover, they can nowadays only be detected by the use of destructive, time-consuming and expensive chemical analyses. We investigat...
Refocusing multi-channel imaging systems are nowadays commercially available only in bulky and expensive designs. Compact wafer-level multi-channel imaging systems have until now only been published without refocusing mechanisms, since classical refocusing concepts could not be integrated in a miniaturized configuration. This lack of refocusing cap...
Carcinogenic and toxic contaminants in food and feed products are nowadays mostly detected by destructive, time-consuming chemical analyses, like HPLC and LC-MS/MS methods. However, as a consequence of the severe and growing regulations on food products by the European Union, there arose an increased demand for the ultra -fast, high-sensitive and n...
Multichannel imaging systems currently feature refocusing capabilities only in bulky and expensive designs. Mechanical movements of the components cannot be integrated in miniaturized designs, preventing classical refocusing mechanisms. To overcome this limitation we developed, as a proof-of-concept (POC) demonstration, a compact low-cost two-chann...
Inspired by nature, many application domains might gain from combining the multi-channel design of the compound eyes of insects and the refocusing capability of the human eye in one compact configuration. Multi-channel refocusing imaging systems are nowadays only commercially available in bulky and expensive designs since classical refocusing mecha...
Questions
Question (1)
We are investigating 2 fluorescent toxins, which fluoresce when illuminated with the same UV laser. However, when illuminating the two toxins with a high power NIR laser, one of the toxins shows two-photon induced fluorescence while the other doesn't. What can be the reason for this? Are there any requirements the molecular structure of the toxin need to fulfill in order to generate the two-photon fluorescence?
Projects
Projects (4)
This project focuses on the development of a compact 4-channel camera system, comprising an RGB, NIR, SWIR and thermal camera, enabling the monitoring of the NDVI index, cellulose absorption and land surface temperature. This development includes the selection of the appropriate sensors, lenses, filters and their optomechanical integration.
The goal of this project is to perform a feasibility study, to investigate the suited spectroscopic sensing techniques enabling a combined gas temperature and NOx detection. This study includes the examination and selection of the optimal sensing principle (fluorescence, emission and/or absorption spectroscopy), the selection of the best suited spectral wavelength range and detection process, and its integration in a fiberoptical sensing demonstrator setup.
