sarbu

 

Head of laboratory

Nicolae SÎRBU
University Professor, Doctor

 

Contact

Address: bd. Ştefan cel Mare, 168, block of study nr. 1, 1-104
Tel: +373 22 23-54-37
Laboratory website: http://lmoe.utm.md/en

e-mail: nicolae.sirbu@sde.utm.md

e-mail: andrei.dorogan@srco.utm.md 

Introduction

The Laboratory of micro-optoelectronics was founded in 1970. Currently, the laboratory is carrying out scientific research and technological development in the field of engineering of new nano- and monocrystalline materials, quantum wells heterostructures, amorphous materials, optics and engineering of micro-optoelectronic devices for various applications in micro and optoelectronics, photovoltaic system, communications, medicine, environmental protection, etc.

Areas of activity:

  • Design and production of laser modules coupled with optical fiber for applications in telecommunications, medicine, metrology, etc.;
  • Development of optoelectronic systems and devices for medicine, energetics, communications, industry;
  • Technical diagnosis of electronic and optoelectronic equipment for optic fiber communication systems;
  • Development of advanced technologies for obtaining mono- and nanocrystalline compounds, crystals from liquid phase and crystals doped with impurities, thin films in vacuum, photodetectors based on birefringent crystals, materials with high photoconductivity, etc.;
  • Production of nanostructures, nano-films, porous materials based on new multicomponent materials, doped with various impurities materials, porous nanomaterials, including porous nanocrystals, nanofibers, nanotubes, quantum well heterostructures and structures for the production of photovoltaic cells and other optoelectronic devices;
  • Development and optimization of optical measurement methods and optical birefringence phenomena with the recording of digital signals in the 0.5 – 6eV energy range using UV, VIS and IR spectrometers. Research on the photoelectric and photovoltaic properties of nanomaterials in a wide temperature range (10 – 300K);
  • Study of electro-optical phenomena, exciton states, energy band structure, photoelectric phenomena in high energies region (6eV); Research of the basic optical parameters of nanocrystals and nanostructures with quantum wells at low temperatures;
  • Research of materials and heterostructures with quantum wells using photoluminescence spectroscopy at low temperatures (10K -300K) in the wavelength range 325nm;
  • Investigation of Raman scattering, Raman resonant scattering and luminescence in the temperature range (10-300K), with the determination of optical and acoustic parameters of the studied materials;
  • Device development with various applications in communications, medicine, illumination and transport.
  • Development of electronic devices for power, command and control with various applications;
  • Development, production and testing of LED modules for various destinations:
  • Street lamps, laboratory testing, obtaining photoelectrometric measurements and optical profile;
  • Exterior lamps for general, public and specialized illumination;
  • Indoor industrial lamps with different angle of light output,
  • Laboratory testing and measurements of photoelectrometric and optical profiling;
  • Production of phyto-lamps for growing different crops and implementing under conditions of small parcels;
  • Study and magnetic field measurement;
  • Investigations on electrical conductivity (DC and AC), optical absorption (UV, VIS and IR), as well as photoelectric properties, including photovoltaic semiconductor materials.

Consulting, Expertise, Services

  • Provision of services in the field of growth (deposition) of crystals, thin layers and multicomponent semiconductor nanostructures, metal films and semiconductors by different methods (Bridgman method, Czochralski method, thermal evaporation or vacuum sublimation method);
  • Provision of services in the investigation of optical, electrical and photoelectric properties of crystalline, amorphous materials; study of optical spectra in the temperature range 10-300K, including optical polarization in the energy range 0.5 – 6eV; calculating fundamental optical parameters using various methods (Kramers-Kronig, dispersion equations method, etc.);
  • Provision of high-resolution structural analysis services (± 0.5Å) through the study of luminescence spectra in the temperature range 10K-300K and energies 0.5 – 4eV.
  • Provision of services in investigating optical phenomena (Raman scattering and Raman resonant scattering in the 10-300K temperature range, including optical polarization;
  • Providing vacuum deposition services by evaporation, vacuum deposition with high voltage magnetron;
  • Provision of synthesis of compounds services by tartar and thermal decomposition (up to 1000 ° C), by ultrasonic (28 kHz 500 W), hydrothermal (up to 180 ° C) method;
  • Provision of services in the production of a device or a limited series of electronic devices;
  • provision of services in the development of LED modules for different destinations and of different consumption powers, according to the beneficiary’s specification;
  • Interdisciplinary research related to materials science, micro and nanoelectronics, telecommunications, pharmaceutical industry, food industry, machine building, medicine and environmental protection;
  • Provision of services in the development of electronic devices for power, command and control, according to the beneficiary’s specification;
  • Provision of services in the production of the technical documentation for the devices, the developed modules and the production preparation.

Examples of Research projects

  1. “Study of semiconductor materials and development of micro-optoelectronic devices for advanced applications”;
  2. “Optical spectroscopy and Mossbauer of compound chalcogenides for photovoltaics”;
  3. “Informational-technological support in the planning, management and control of the production system of microwires and microwire based products”;
  4. “Mobile pilot mammography equipment installation for early detection of breast cancer on the territory of the Republic of Moldova”;
  5. “Technological systems for obtaining micro and magnetic nanowires for MEMS applications”.

New Innovations from the Micro-Optoelectronics Laboratory

1. Mobile pilot mammography equipment installation for early detection of breast cancer on the territory of the Republic of Moldova

Description of the elaboration. Co-financer: M-INTER-FARMA S.A, Chisinau, Republic of Moldova.

Development, production, testing and implementation of a mobile mammography system for the preventive detection of breast cancer with national coverage, on the body of a car in compliance with the NFRP-2000 norms, at a substantially lower cost price compared to similar systems abroad.

See video

Features of this mobile system are:

  • The possibility to perform breast screening in any village, commune, district of the Republic of Moldova;
  • Access to and supervision of the socially vulnerable population, including the elderly, who are more prone to cancer;
  • Possibility of going to place of residence of the patient, with emergency screening.
2. Quantum therapy device

Quantum therapy devices are developed and manufactured based on laser diodes and super-luminescent ultraviolet diodes. The device has two broadcast terminals with separate steering and control. Thanks to the use of a high-performance microcontroller, the device allows selection of the working frequency, the optical power of the emission, the working time, memory for 20 selected regimes, network and autonomous power supply.

Advantages are related to the expected economic and social effect: Wide functional possibilities, low power consumption, reduced size, low cost.

Field of implementation: Medical institutions.

Possibilities for exploitation on the local and global markets: The devices are already being used in clinics, hospitals, as well as individually.

3. Device for tissue diagnosis of the oral cavity

Dispozitiv diagnoza tesutului cavitatii bucale

This electronic device provides a  diagnosis of the tissues of the oral cavity. The device consists of mobile probes and an element for moving the amplifier and the manometer. The control circuit is based on a microcontroller that allows a simple control system, for ease of use. The microcontroller allows simple upgrading of the device by reprogramming. The use of microcontrollers, LCD screens, galvanic cells, and pressure elements in this modern device, meets all user requirements.

Innovative aspects, Advantages:

  • Reduced price;
  • Increased accuracy;
  • Ease of use.
4. Laser diode module with collimator

The collimator laser diode module has a radiant flux power of 500 mW, an emission wavelength of 1.06 μm and the fascicle divergence angle of less than 3 mrad. It was developed to obtain the minimum divergence angle of the optical fascicle by forming a system with cylindrical and spherical lenses. A cylindrical quartz microlens with a radius of 50 μm serves to focus the spot light in the form of an ellipse; the optical fiber is fixed at a distance of 25 μm. The light fascicle is collimated by a 10 mm diameter spherical lens with a focal length of 15 mm. Optical lenses are covered with anti-reflection layers.  

Innovative aspects, Advantages:

  • Reduction of the divergence angle of the fascicle below 3 mrad;
  • Simplification of technology.
5. Transmission mode for optical communications

The module reduces the coupling losses using a simplified original method for fiber optic communication systems. The original manufacturing method was developed using an InGaAs / InGaAsP / InGaP / GaAs double quantum hollow laser diode, mounted in an original 5-pin module, equipped with a photodiode and a thermistor for temperature monitoring. The laser is fiber coupled, using fiber optics with small numerical aperture (FO) and a microlens.

Innovative aspects, Advantages:

  • Decreased coupling losses in the optical module;
  • Technological simplification.

Field of implementation:

  • Fiber optic communication systems, pumping of Er + doped devices;
  • Characterization of materials;
  • Raman spectroscopy.
6. Microlenses for optical fibre coupling

Development of an original method of manufacturing fibre optic components. The tapered end with microlens was formed by a combined method of chemical etching and fusion process. The optical fibre was slowly immersed in an acid corrosive to obtain the conical shape of the fibre ends. To form the hemispherical lens, the fibre end was heated in an electric arc. For the coupling of high-power laser diodes with optical fibres, convex microlenses were designed and manufactured on glass fibre. The radiation injection efficiency depends not only on the curvature but also on the length of the lens. The technology has been developed for different modes of operation lenses with a radius from 10 to 300 micrometres and length L from 50 micrometres up to 3 mm.

Innovative aspects, Advantages:

  • Reduction of laser diode coupling losses in optical communication systems;
  • Decrease in the number of coupling elements;
  • Simplifying and reducing the price of coupling technology.

7. Air ionizer for prophylactic treatment

A high voltage source was developed for an air ionizer based on a pulse energy transfer scheme, which allows fine tuning of the output voltage. The scheme is characterized by the use of the microcontroller with nine operating modes and advanced functionalities. All the information is displayed on an LCD screen, the modes and working parameters are selected from the touchpad. The power consumption of the air ionizer is 10W; current consumption 0.05A; output voltage 15 – 35kV; short-circuit current 50 μA.

Innovative aspects, Advantages:

Use of microcontrollers, LCD screens, touchpad, together with modern components.

8. Lighting system with low consumption

The system consists of lighting modules based on light-emitting diodes and a control block. The control block ensures the automatic start / stop of the illumination, according to the level of natural lighting. The system includes short circuit protection, overload protection and sensitivity adjustment. The control block allows the setting of 25 individual working programs for street lamps and lighting of houses.

Innovative aspects, Advantages:

  • Significantly reduced energy consumption;
  • Automatically guided work using photoreceptors, noise sensors;
  • Overvoltage and short circuit protection network.

Brief CVs

Prof. Dr. Hab. Nicolae Sîrbu 

Prof. Dr. Nicolae Sîrbu is a senior researcher in the domain of micro-optoelectronic devices and spectroscopy and is the Head of the Laboratory of Micro-Optolectronics, TUM. His research includes:

  • Publication of 430 articles in national and international scientific journals, 31 patents; all these awarded with 24 gold and silver medals at different scientific invention events.
  • In the past 5 years Prof. Dr. Nicolae Syrbu has published 3 monographs, one of which was published in the US, over 25 peer-reviewed articles in international journals.
  • He participated in the implementation of 4 international, institutional and thematic projects investigating the optical properties and optical parameters of anisotropic crystals and nanostructures used in optoelectronics and microelectronics.

Relevant publications: 

  1. Stamov I.G., Syrbu N.N., Dorogan A.V., Energetic band structure of Zn3P2 crystals, Physica B: Condensed Matter, 2013, no 408(1), pp. 29-33.
  2. Stamov, I.G., Syrbu, N.N., Dorogan, A.V. Photodetectors and birefringence in ZnP2–С2h5 crystals, Physica B: Condensed Matter, 2013, no 412 (1), pp. 130-137.
  3. Syrbu, V. Dorogan, A. Dorogan, T. Vieru , V. Ursaki,V. Zalamai, Optical spectra in the region of exciton resonances in quantum wells and quantum dots of In0,3Ga0,7 As/GaAs  heterostructures, Superlattices and Microstructures; 2012; 52; 738-749. 

Nicolai Sîrbu’s Contact Details:

E-mail: nicolae.sirbu@sde.utm.md, syrbunn@yahoo.com

Phone: +37369007753

 

Dr. Andrei Dorogan

Dr. Andrei Dorogan was awarded the title of Doctor of Physical Sciences in 2019. At the moment working as a scientific researcher in the Laboratory of Micro-Optolectronics, TUM and as a university lecturer at TUM. He obtained the Master Diploma in 2006 as a specialist in Telecommunications. In the past five years he published over 15 articles in peer-reviewed journals, participating at various International Scientific Salons of Inventions and international conferences. Research Interests: technology of semiconductor materials and structures; devices for different optoelectronic and communication systems; telecommunication systems.

Relevant publications:

  1. Svatopluk Civiš, Zdeněk Zelinger, Václav Nevrlý, Andrei Dorogan, Martin Ferus, Vladimir Iakovlev, Alexei Sirbu, Alexandru Mereuta, Andrei Caliman, Grigore Suruceanu, Eli Kapon. Near-infrared wafer-fused vertical-cavity surface-emitting lasers for HF detection, Journal of Quantitative Spectroscopy & Radiative Transfer, 2014, no 147, pp. 53–59.
  2. A. Dorogan. Elaboration of the microchip concept with 3D movement for laser diode – optic fiber coupling, Engineer Meridian 9, vol. 2. Ed. UTM, Chişinău, 2007, p.76.
  3. A. Dorogan. Microchip for optic modules used in telecommunications, International Scientific Conference “TMCR-2007” Ed. XI, UTM, May 31- June 3, Chişinău, 2007. Vol.1 Ed. UTM. p. 471-475.

Andrei Dorogan’s Contact Details:

E-mail: andrei.dorogan@srco.utm.md, dorogan.andrei@gmail.com

Phone: +37379518887

 

For H2020 and other EU funding opportunities, please contact Prof. Michael Remes

Email: michael.remes@adm.utm.md

11th February 2020, Edited by Michael Remes, EFPC