BrainMap

Mr. Cristian Udrea

Ph.D.

Researcher - INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA

Researcher

I have expertise in lasers (alignment, polarimetry, interferometry, imaging, spectroscopy). The PhD thesis topic was about laser ablation (production of nanoparticles in liquid medium ). Also, I was project coordinator for 1 year , at the PN-III-P2-2.1-PED-2021-1939 (Physical encryption and compactization of data via optical Fourier Transform). Another expertise is in THz radiation topic like: THz imaging and spectroscopy.

Web of Science ResearcherID: L-1510-2015

Curriculum Vitae (09/07/2026)

Expertise & keywords

Generation of superhydrophobic surfaces by exposure of materials to laser beams Call name: P 1 - SP 1.1 - Proiecte de cercetare pentru stimularea tinerelor echipe independente - TE-2021
PN-III-P1-1.1-TE-2021-0873 2022 - 2024

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA (RO)

Affiliation:

Project website: http://sh-mat.sol.inflpr.ro

Abstract:

Nanoscience and nanotechnology research is strongly encouraged and developed nowadays due to its positive impact on the development of new areas such as nano-biology, nano-electronics, nano-photonics and micro- and nano-fluidics.

Recently, superhydrophobic surfaces, for the which the water contact angle is higher than 150° and sliding angle less than 10°, have received attention due to the many potential applications ranging from biological to industrial processes.

Many living beings in nature, including the lotus leaf, rice leaf, butterflying wing and water-strider legs exhibit excellent superhydrophobicity. Such functionalized surfaces possess several unique beneficial properties, i.e. extreme water repellency, self-healing, self-cleaning, anti-bacteria, anti-corrosion, enhanced heat transfer, drag reduction and improved corrosion resistance.

The purpose and in the same time the novelty of the project is to design and realize an innovative, flexible and low cost system for producing of patterned superhydrophobic metallic surfaces. The main goal of this patterned superhydrophobic metallic surfaces is to obtain a fingerprint device to be used on polymeric materials such as: polydimethylsiloxane-PDMS; polyethylene terephthalate-PET, synthetic latex polymers. Some of its innovative applications are to create superhydrophobic surgical gloves, superhydrophobic metallic surfaces for naval industry and also superhydrophobic food packaging for preventing COVID-19 spreading!

Physical encryption and compactization of data via optical Fourier transform Call name: P 2 - SP 2.1 - Proiect experimental - demonstrativ
PN-III-P2-2.1-PED-2021-1939 2022 - 2024

Role in this project: Project coordinator

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA (RO)

Project website: https://phycod.sol.inflpr.ro/

Abstract:

The encoding of data may be used for secrecy and/or compactization. It is useful in military applications, in security and any circumstance in which the content of the information is sensitive and the opportunities for data transmission are limited, such as satellite communication. Mathematical transforms such as Hadamard or, to a less extent, Fourier, if they are applied to input data having a high degree of redundancy, turn the input into encrypted data with many empty spaces. Redundancy is converted into sparsity. The Fourier transform has the advantage that can be performed physically easy as diffraction on a lens for instance. In optical processing of information encryption of data, especially in the 4f configuration, is done for some time. With the advent of digital phase shift holography significant progress has been made in the field in terms of convenience and complexity. In scientific literature there are a number of theoretical and experimental techniques which share some but not all of the following aspects: encryption of data, compactization of data, physical realization, digital recording, phase shift interferometry, holography. We propose an original experimental technique which combines the advantages of all these aspects. Input data which may be presented as a transmission or a reflection mask will be recorded via means of phase shift digital holography as an encrypted and compressed file. As a secondary direction of research, we propose the reciprocal, the use of the recursive algorithm for the creation of diffractive optical elements for encryption and compactization of data. One may force the encrypted data to take the form of a known, compact amplitude distribution and an additional phase factor. In this case the data is encrypted numerically, not physically, but it can be decrypted physically using a phase spatial light modulator.

THz scanning interferometer with enhanced resolution using amplitude control Call name: P 1 - SP 1.1 - Proiecte de cercetare pentru stimularea tinerelor echipe independente - TE-2021
PN-III-P1-1.1-TE-2021-0949 2022 - 2024

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA (RO)

Affiliation:

Project website: https://thezseract.sol.inflpr.ro

Abstract:

The frequency region between microwave and infrared part of the spectrum, called terahertz (THz), encompasses electromagnetic waves oscillating at frequencies, loosely defined, in the range 0.1 to 30 THz. Generating or detecting radiation in this range has proved quite challenging, owing mainly to the presence of background sources of incoherent light. Nevertheless, this radiation has unique properties that makes it particularly attractive for applications ranging from bio-medical imaging, national security and packaged goods inspection to remote sensing and spectroscopy. Moreover, with an energy between 0.4 and 124 meV it is non-ionizing and, therefore, not harmful to the living world. Today, the most accessible technique for recording or measuring data in this spectral range, except time-domain spectroscopy/imaging, is the single-pixel imaging (SPI). In this view, a given THz scene may be achieved either by using raster scanning (RS) or multiplexing (MS) techniques. Thus, achieving sufficient resolution for such a THz image is the main challenge. With this proposal we intend to use RS or/and MS in order to improve the resolution of imaging at submillimeter radiation, and demonstrate its application to Fourier transform spectroscopy (FTS) and phase shifting interferometry (PSI) at these wavelengths range. This is because both FTS and PSI are readily applicable to SPI and interferometry is a reliable and non-invasive testing tool.

Laser-based device for microplastics detection in water Call name: P 2 - SP 2.1 - Proiect experimental - demonstrativ
PN-III-P2-2.1-PED-2019-1264 2020 - 2022

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA (RO)

Project website: http://sol.inflpr.ro/projects/in-progress/ped465

Abstract:

One major side effect of nowadays abundance of plastic products is microplastic pollution, where small size polymer particles of diverse origins enter the environment, only part of them being removed by the wastewater treatment plants.

Despite the differences that exist at this point about the definition of microplastic particles, if considering only their sizes, elements smaller than 5 mm in diameter with no lower limit are considered. They constitute a wide range of chemically complex materials, often with additives and fillers influencing properties such as color, density, durability. This diversity in properties and wide particle size range means that as a group of analytes, they are challenging to efficiently detect and identify in complex environmental matrices, especially when nanometric range dimensions are involved.

This project proposal aims at developing a new laser-based device for detection of microplastics in water.

Its scope derives from the need to find a way for faster and accurate detection of microplastic particles in fluids with a limited number of measurements, easy processing and sampling. For this, we will develop a subsystem capable to detect microplastics in water droplets using enhanced Raman scattering spectroscopy. This will be joint with another subsystem based on optofluidic measurements at the surface of an air bubble generated in polluted bulk water sample performed by real time surface and interfacial tension measurements. The interaction between microdroplets and bubbles with laser beams belongs to a rather new field of multidisciplinary research, the optofluidics, which deals with the interaction of optical radiation with fluid systems. The combination of the enhanced sensitivity of the Raman scattering technique obtained using very small samples (microdroplets) with the latest developments in the topics of microfluidics and optical spectroscopy may constitute an advance in the field of online monitoring of water pollutants.

Millimeter Wave (THz) Time Domain Spectroscopy Instrument for Dangerous Substances Identification Call name: Joint Applied Research Projects - PCCA 2013 - call
PN-II-PT-PCCA-2013-4-0967 2014 - 2017

Role in this project: Key expert

Coordinating institution: INSTITUTUL DE STIINTE SPATIALE-FILIALA INFLPR

Project partners: INSTITUTUL DE STIINTE SPATIALE-FILIALA INFLPR (RO); INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA (RO); UNIVERSITATEA POLITEHNICA DIN BUCURESTI (RO); UTI GRUP S.A. (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA (RO)

Project website: http://www2.spacescience.ro/projects/project-290/

Abstract:

The security problem of a country it was and still remains an important domain. In this way, the development of devices and systems, in inner production which ensure and improve the security level must be high priority. The research made in this way ensures not just an economical development, but also an access to the top of the technology.

In the last years, the development of the THz technology tends to become gauge devices in complex substances identification. From this, become almost clear the way to use such systems in the security domain, for identification of the dangerous substances, fake drugs, dangerous objects imagistic etc..

THz radiation covers a slightly investigated area until now from the electromagnetic spectrum, between microwaves and infrared. Because of those properties, the molecular structure of a substance could be determinate from the absorption or emission of THz radiation. Having such spectrum (absorption or emission) we can identify a complex substance. With a large data base of THz domain spectrums we can identify more substances.

In the same time, the THz radiation photons have a weak energy, so the radiation is not dangerous for human being (is not an ionizing radiation). THz radiation being a broadband, it is obey to the dispersion, diffraction and divergence phenomena, doing quite difficult the handling of such beam. However, it is possible the quasi optical coupling using the lenses, because some of the dielectrics are transparent at THz radiations. On the other hand, from the diffraction point of view, THz radiation has a behavior specific to microwaves, so we need some bigger optical systems to control the spatial propagation.

The consortium consisting of: Institute of Space Science, National Institute for Laser Plasma and Radiation Physics, Research Center of Optoelectronics, from University Politehnica of Bucharest and an industrial partner UTI Group – have propose to realize an active, portable device to identify dangerous substances in the THz domain for security. The product will be a novelty on the national and international plan, because of it compact structure, response and low cost.

In this project we take account of: design and accomplishment of a molecular spectroscopy setup in the THz domain and the validity of the spectroscopic setup in the national security domain.

Compressive THz Imaging and Hadamard Spectroscopy for Space Applications Call name:
CDI STAR 153 2012 - 2015

Role in this project: Key expert

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA (RO); UNIVERSITATEA POLITEHNICA DIN BUCURESTI (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA (RO)

Project website: http://thzimaging.ila.inflpr.ro

Abstract:

THz domain spectroscopy probes the characteristic vibrational and rotational modes of molecules. Due to this property, the molecular structure of the analyzed samples can be determined from the emitted or absorbed THz radiation. Reciprocally, knowing the absorption or emission spectra, the substances can be identified. The better the far-infrared spectra are known, the highest the number and the complexity of identifiable substances. Additionally, given the weak energy of far-infrared quanta, these radiations are not harmful to the living world. From these two reasons alone, the THz range of electromagnetic spectrum is associated today with two major research directions: Space (observation of chemical composition of the atmosphere and surface of comets, planets, including the Earth, and satellites; probe the molecular chemistry of the universe) and Defense (identification of hazardous substances of interest, home defense and remote imaging of hidden dangerous objects).

The project aims to conduct research regarding: formation and recording of digital images in the THz domain, acquisition by Compressive Sensing and reconstruction of digital images in the THz domain, spectroscopy of interesting space (outer space) sources.

For this purpose, the following up to date methods will be applied during the project: Hadamard spectroscopy, Numerical imaging with spatial multiplexing, Digital Micromirror Devices (DMD) for spatial modulation and software for digital optics, Compressive sampling for image recording and compression.

THz imaging spectroscopy involving measurement of both intensity and spatial relationships among several spectral line features (e.g. emission line ratios, emission region morphology etc) is a powerful extraction tool. Due to technological advance, it becomes feasible to build, for space applications, a spectrometer with optimized data acquisition, small mass and dimensions, no moving parts.

Our project research will proceed with this trend and will materialize into an experimental model for a Hadamard image spectrometer for THz domain, dedicated to space applications. The principle of the instrument is: a THz source (which may be collimated or focused, with THz optics) is incident upon specially designed Hadamard masks. Technically, the masks could be mechanical mask, DMA or even a Liquid Crystal on Silicon (LCOS). The interaction with the masks (which can be obtained either by transmission or reflection) followed by radiation collimation or focusing (depending on experimental needs), results in the optical computation of multiplexed image projections. The projections are sensed by a THz detector, which converts them into an electrical signal, and finally transmitted to a computer for processing. The masks sequencing is controlled by a Modulator and the projections are acquired by a Data Acquisition module, both controlled by the computer.

Since the project content regards the "technology research" -one of the seven relevant ESA programs in recent past, present and future- it will foster the creation of strong and long-term relations between Romanian entities and ESA. From the perspective of ESA-Romania Task Force priorities, the project subject is of interest for the area of "sensors and scientific instruments".

Laser-based manufacturing system for biotech nanoparticles production Call name:
ERA-NET MANUNET BIO.NANO.LAS/ 7-022/ 2010/ 2010-2012 2010 - 2012

Role in this project: Key expert

Coordinating institution: RTM SpA

Project partners: RTM SpA (); INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA ()

Affiliation: RTM SpA ()

Project website: https://www.manunet.net/success-stories/38-laser-based-manufacturing-system-for-biotech-nanoparticles-production.html

Abstract:

FILE DESCRIPTION	DOCUMENT
List of research grants as project coordinator or partner team leader
Significant R&D projects for enterprises, as project manager
R&D activities in enterprises
Peer-review activity for international programs/projects