Project Description

 

Project code: PN-II-RU-TE-2014-4-2412; Unitatea Executivă pentru Finanţarea Învăţământului Superior, a Cercetării, Dezvoltării şi Inovării - UEFISCDI Romania.

Contract no.: 117/2015

Contract duration: 2 years

PN II Program Name: Human Resources (RU)

Subprogram: Research projects for the stimulation of the forming of young independent research teams (TE)

Project Title: Next generation highly efficient LASER light sources: from micro emitters to full scale optical devices. (NewLASERDev)

Project manager: Valentin BARNA  

Coordinator: University of Bucharest (Address: Bd. M. Kogalniceanu, nr. 36-46, Sector 5, Bucharest)

 

Project description. Main objectives and expected results.  

            Nowadays, the possibility of finding and employing new materials and considering novel flexible designs for engineering compact and reliable laser sources is a highly motivating challenge. Difficulties arise in combining low building costs, "green" materials, small size devices and possible mouldable shapes (for certain applications), sample specific lasing frequencies, high emission efficiency and substrate compatibilities. Uncovering materials and imagining systems that can assemble all (or most) of these properties could lead to major enhancements in the field and significant expansion of potential technological applications and devices involving these particular optical amplifiers. The main objectives of the project are to design and fabricate new types of lasers by using non-ordinary materials (that have not been previously mentioned in the scientific literature as potential candidates for active media nor resonant cavity-like substituents in Laser systems) while possessing remarkable features and enhanced properties with respect to extant devices. We wish to tackle these aspects, build and characterize our novel devices by modern techniques, as both micro-scale gadgets and full size systems, in order to also bring important updates for fundamental science and try to gain knowledge of the laws governing the operating amplification mechanisms at small scale (molecular) levels.

            Recently, lasing phenomena and random lasers (RLs) have been the subject of intense theoretical and experimental studies. A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. Lasers have currently a plethora of applications spanning from common consumer devices such as optical disk drives, laser printers, barcode scanners to fiber-optic and free-space optical communication. They are highly required also in medicine for laser surgery and various skin treatments, while in industry for cutting and welding various materials. They are exploited also in military and law enforcement devices for marking important targets, also for measuring range and speed. Thus, improving these devices (in terms of size, costs, emission properties and efficiency etc) is a significant point in nowadays research priorities. Random lasers are captivating examples of scientific topics that synergize multiple scattering of light and optical amplification. Various hosts such as semiconductor powders, silver nanopowders, polymers, liquid crystalline materials  and even human tissues have been employed for engineering original and exotic systems for obtaining light amplification and eventually laser emitters. In particular, in a random laser, several discrete modes are optically amplified within the host medium and exhibit individual resonant wavelengths with the spectral interval being usually in the range of a few nanometers. Such emission, namely coherent random lasing, was demonstrated to derive from resonant feedback in localized modes, two-scatterer cavities, or particular nonresonant feedback that generates modes extended over the system. The mélange of light localization and stimulated emission is remarkably captivating due to the specific properties of each distinctive lasing source, accompanied by unique emission characteristics (given by localized modes in every sample). Lasers from random systems and also from photonic crystals have extremely promising properties that a conventional laser device cannot provide  and unmistakably represent large important research areas at international level (both from fundamental scientific and application/technological point of views). There are certain barriers that presently hinder some fundamental aspects, such as the necessity of using high quality resonant cavities (usually bulky size, many optical elements prone to misalignment and damage), use of some non environmental friendly and hazardous materials / and system designs (i.e. volatile solvents from dye-laser sources), need for emission wavelength tunability, difficulties in obtaining compact and adaptable emitters for the first therapeutic NIR window (650-1350nm) used in medical therapy/ imaging, fluorescence imaging guided surgery/drug delivery, high overall manufacturing expenses etc. Under these circumstances, the possibility of finding and employing new materials and considering new flexible designs for engineering compact and reliable laser sources is a highly motivating challenge.

 

proiect
www.softmatter.org     Volume 6  |  Number 2  |  21 January 2010  |  Pages 197–424   Property of Soft Matter Journal

 

This study and goals will be carried out initially by developing theoretical models and numerical simulations and then experimentally, in laboratory research activities.

The materials to be used in crafting these systems will also be doped with various other components (oxides, semiconductor powders, metals etc) for enhancing certain physical properties and increasing the emission efficiency in the developed systems.

The expected results are centered at achieving laser action in absence of mirrors and boundaries - which thrusts towards obtaining unique tunable and flexible laser source material systems. By making use of an adaptable system design, we make a significant step forward in obtaining for the first time laser action in confined or freely suspended dye doped thin films. The mismatching of refractive indices, the irregular shape of the air–mixture interface and the scattering cross sections are some of the parameters accounted for obtaining the presented outcome. As objectives we shall test various experimental possibilities by using different laser dyes / "special" mixtures in combination with distinct geometries for suspending the gain media. One goal is also to investigate on how the menisci shape and air–active media interfaces have an influence on the emission properties (fluorescence and directional stimulated emission). These studies will further allowed us to rule out etalon cavity effects.

            The emission parameters will be investigated for dependence upon temperature, input polarization and optimized for the best overall efficiency. The main objectives will include characterizing the lasing systems at different levels: °Structural and morphological investigations by means of optical and scanning probe microscopy. °Non-linear optical and electro-optical characterization of the engineered systems.  °Spectroscopic investigations using a variety of sources of suitable emission characteristics. °Dielectrical and magnetical characterization by impedentiomentry, cyclic voltametry etc. °Testing under mechanical and temperature stress. °Selection of the best and most efficient systems for possible optical/photonical applications.      

Brief objectives & results

The main objectives of the project are to design, fabricate and characterize new types of lasers by using non-ordinary materials (that have not been previously mentioned in the scientific literature as potential candidates for active media nor resonant cavity-like substituents in Laser systems) while possessing remarkable features and enhanced properties with respect to extant devices.          

The expected results include building and characterizing the proposed novel laser devices by modern techniques, as both micro-scale gadgets and full size systems, as well as to bring important updates for fundamental science and try to gain knowledge of the laws governing the operating amplification mechanisms at small scale (molecular) levels. The results also include dissemination of the obtained research results (theoretical and experimental) by means of published scientific papers and participation at scientific conferences & meetings. 

 

 

 

 

Pagină actualizată la 13 Februarie 2017.