Luis Cerdán's research while affiliated with University of Valencia and other places

Publications (61)

Article
Full-text available
The theoretical prediction of molecular electronic spectra by means of quantum mechanical (QM) computations is fundamental to gain a deep insight into many photophysical and photochemical processes. A computational strategy that is attracting significant attention is the so-called Nuclear Ensemble Approach (NEA), that relies on generating a represe...
Article
Amplified Spontaneous Emission (ASE) properties and ASE threshold are usually investigated for the characterization of a candidate active material for laser applications. However, the comparison among different materials is often hampered by the use in literature of several different methods to estimate the ASE threshold. In this work we quantitati...
Article
Nearly half a century ago, the German physicist Hermann Haken proved that the laser dynamics could be described, under certain conditions, by the Lorenz equations, the paradigm of deterministic chaos. Unfortunately, its experimental realization has remained elusive for conventional laser materials and cavities mostly due to the extreme pumping cond...
Article
We present the first examples of alkylated derivatives of the macropolyhedral boron hydride, anti-B18H22, which is the gain medium in the first borane laser. This new series of ten highly stable and colorless organic-inorganic hybrid clusters are capable of the conversion of UVA irradiation to blue light with fluorescence quantum yields of unity. T...
Article
The increasing number of solution-processed laser compounds that can be implemented as low-cost, flexible, and/or integrated devices, makes necessary the development of reliable methods to delineate all their amplifying signatures and thus to open the door to appropriate cross-sample comparisons. Seeking to solve this problem, a new formalism to re...
Article
Full-text available
Cellulose nanocrystals (CNCs) display a set of unique properties such as surface charge, nanometric size, and giant dipole moment that have never been considered as suitable to tame the luminescent properties of organic dyes upon soft and hard photoexcitation. Herein the first comprehensive analysis on the photonic behavior of laser dyes adsorbed o...
Article
In the search for innovative new light sources, the discovery that solutions of the boron hydride anti-B18H22 generate photostable blue laser emission stands out in its significance as the first laser borane. Surprisingly, though, the laser performance of anti-B18H22 (~10 % efficiency) does not match the expectations based on its exceptional photop...
Article
The generation of Amplified Spontaneous Emission (ASE) is routinely used to assess the performance of active materials prior to developing thin film lasers. The Variable Stripe Length method has been profusely used for decades to measure the optical gain in these materials and devices, but experimental and theoretical evidences cast doubts upon its...
Article
The computationally-aided photophysical and lasing properties of a selected battery of BOPHYs are described and compared to those of related BODIPY counterparts. The present joined theoretical-experimental study helps to put into context the weaknesses and strengths of both dye families under different irradiation conditions. The chemical versatili...
Article
The front cover artwork is provided by Maria Cristina Devesa, the Organic Chemistry Group from the Universidad Complutense de Madrid (UCM), the Molecular Spectroscopy Group from Universidad del País Vasco (UPV/EHU) and the Laser Materials Group from Instituto Rocasolano (CSIC). The image shows the bright and stable deep‐red emission from the design...
Article
The Front Cover illustrates bright and stable deep‐red emission from a designed aza‐BODIPY chromophore. By careful selection of the substitution pattern of the fluorophore, the laser emission can be pushed towards the near‐infrared region of the spectrum. More information can be found in the Article by A. Prieto‐Castañeda et al.
Article
In this article the design and characterization of a set of novel red‐emitting laser aza‐BODIPYs is reported. These dyes are endowed with efficient fluorescence and laser emission, and outstands by their high photostability, a key parameter to guarantee long–lasting emission in any (bio)technological application. The applied synthetic protocol allo...
Article
The exceptionally rich chemistry of BODIPY dyes enables the fine-tuning of their optical properties for advanced applications. However, the stereochemical and steric control of their photonic behavior has not been studied despite the key role that the spatial arrangement of the chromophoric units plays in raising light-induced exotic emission state...
Article
The Variable Stripe Length (VSL) method is a very popular tool to measure the optical gain in thin film active devices. However, over the last decade experimental and theoretical evidence has been reported that cast doubt upon its reliability and that seriously discourages its application. Continuing in the path of highlighting the uncertainties as...
Article
The generation of circularly polarized laser emission (CPLE) in photonic devices has attracted increasing attention due to the prospects of using CP light in displaying technologies or advanced microscopies. Organic systems excels as laser materials across the whole visible spectrum, and despite many of them display circularly polarized luminescenc...
Article
N-BODIPYs (diaminoboron dipyrromethenes) are unveiled as a new family of BODIPY dyes with huge technological potential. Their synthetic access is accomplished from a judicious design focused on stabilizing the involved diaminoboron chelate. Once stabilized, achieved N-BODIPYs retain the effective photophysical behavior exhibited by other boron-subs...
Article
The direct generation of efficient, tunable, and switchable circularly polarized laser emission (CPLE) would have far-reaching implications in photonics and material sciences. In this paper, we describe the first chiral simple organic molecules (SOMs) capable of simultaneously sustain significant chemical robustness, high fluorescence quantum yield...
Article
We present a low-temperature versatile protocol for the fabrication of plasma nanocomposite thin films to act as tunable emitters and optical gain media. The films are obtained by the remote plasma-assisted deposition of a DCM 4-(dicyano-methylene)-2-methyl-6-(4-dimethylamino-styryl)-4H-pyran (DCM) laser dye alongside adamantane. The experimental p...
Article
B18H20(NC5H5)2 is a rare example of two conjoined boron hydride subclusters of nido and arachno geometrical character. At room temperature, solutions of B18H20(NC5H5)2 emit a 690 nm fluorescence. In the solid state, this emission is shifted to 620 nm and intensifies due to restriction of the rotation of the pyridine ligands. In addition, there is a...
Article
Full-text available
The production of efficient, tunable, and switchable circularly polarized laser emission would have far reaching implications in optical communications or biophotonics. In this work, it is demonstrated the direct generation of circularly polarized (CP) laser emission in achiral and isotropic dye laser systems without the use of extracavity polarizi...
Article
Full-text available
The design and synthesis of the first organic dyes enabling spontaneous for- mation of stable J-aggregates in common organic solvents without additives is described. The new dyes are O-BODIPYs with a B-spiranic 4,4-diacyloxyl substitution pattern. Key to the effectiveness of the J-aggregation process is the high conformational rigidity of the B-spi...
Article
Emission from electronically excited species forms the basis for an important class of light sources-lasers. So far, commercially available solution-processed blue-emitting laser materials are based on organic compounds or semiconductor nanocrystals that have significant limitations: either low solubility, low chemical- and/or photo-stability and/o...
Article
Cationic nanoparticles (NPs) demonstrate advantages over similar anionic systems in relevant applications such as nanocarriers and biomarkers. To harness their unique properties and full potential in bioimaging, a clear understanding of the factors controlling the emission performance of dye-doped cationic NPs, especially under drastic pumping cond...
Article
A straightforward synthetic protocol to directly incorporate stabilized 1,3-dicarbonyl C nucleophiles to the meso position of BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) is reported. Soft nucleophiles generated by deprotonation of 1,3-dicarbonyl derivatives smoothly displace the 8-methylthio group from 8-(methylthio)BODIPY analogues in the...
Article
The donor and acceptor concentration effects on Förster resonance energy transfer (FRET) and laser properties of polymer nanoparticles (NPs) highly doped with two dyes are comprehensively analyzed. Rhodamine 6G (Rh6G, donor) and Nile Blue (NB, acceptor) are incorporated into anionic methacrylic NPs 40 nm in size, in concentrations [Rh6G] = 1–9 mM a...
Conference Paper
The first laser borane, anti-B18H22, exhibits blue laser emission at 406nm with an efficiency of 9.5 % and a photostability superior to that of commercial laser dyes, providing a new solution to an old problem.
Article
In this paper we show that dye distributions within polymer core/shell nanoparticles (NPs), grown in multiple steps, are not controlled only by the synthesis route, but are governed by dye diffusion between core and shell, resulting in dye distributions completely different from the targeted ones. We show that the Förster Resonance Energy Transfer...
Article
A new library of E- and C-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) derivatives has been synthesized through a straightforward protocol from commercially available BODIPY complexes, and a systematic study of the photophysical properties and laser behavior related to the electronic properties of the B-substituent group (alkynyl, cyano, vin...
Article
Full-text available
Although rape is an event with a high incidence worldwide, there is currently no single consensus about both the general effects and the diagnosis and treatment of this. To evaluate the consequences of rape, a teenage girl was evaluated at two moments: a month-and-a-half and then a year-and-a-half after being raped. Clinical measurements, neuropsyc...
Article
The synthesis of nanoparticles (NPs) for which only a single property is modified in a controlled manner is a challenge due to the fact that several physicochemical parameters are entangled. This letter assesses, from both experimental and theoretical points of view, the critical dependence on the charged-surface interfacial effect of the laser beh...
Article
Full-text available
Herein, for the first time, outstanding laser performance is demonstrated in liquid solution and solid state by naturally assembling excimers of organic fluorophores (rosamine dyes). Highly efficient and photostable laser dye properties, with broadened tunability covering 80 nm in the red spectral region (590–670 nm), is attributed to the coexisten...
Article
Over the last decade, significant advances have been made toward the development of practical, tunable solid state dye lasers, which resulted in improved lasing efficiency with reduced dye photodegradation. To achieve this goal, a “chemical” approach was followed, where attention was focused onto the particular dye/host interaction and compatibilit...
Article
A new and facile strategy for the development of photonic materials is presented that fufills the conditions of being efficient, stable, and tunable laser emitters over the visible region of spectrum, with the possibility of being easily processable and cost-effective. This approach uses poly(methyl methacrylate) (PMMA) as a host for new dyes with...
Article
Efficient random lasing (RL) from self-assembled dye-doped latex nanoparticles (d = 50–380 nm) presenting size polydispersity is reported. This new system exhibits a very good chemical compatibility between dye (Rhodamine 6G) and polymer as well as a high refractive index contrast between nanoparticle and surroundings (air), in such a way that its...
Conference Paper
Presently, the development of easily processable and cost-effective laser materials fulfilling the conditions of being efficient, photostable and broadly tunable over the visible spectral range, is an area of active research driven by the wide range of possible practical applications [1-3]. Nevertheless, despite this extensive activity up to now no...
Article
Full-text available
The use of commercial long-wavelength (>650 nm) laser dyes in many biophotonic applications has several important limitations, including low absorption at the standard pump wavelength (532 nm) and poor photostability. Here, we demonstrate that the use of Förster type (FRET) energy transfer can overcome these problems to enable efficient, stable nea...
Article
Active waveguides with high surface roughness due to phase separation in polymer blends can sustain wave-guided coherent random lasing, paving way to the development of integrated devices technologically and economically more favorable that the ones based on nanopatterning. In spite of the vast amount of work on organic thin film lasers carried out...
Article
Long-wavelength (660–740 nm) coherent random lasing (RL) in slab waveguides consisting of poly(2-hydroxyethyl methacrylate) (pHEMA) incorporating silsesquioxane nanoparticles (POSS) doped with the red-emitting dyes LDS722 and LDS730 is presented. Energy transfer from a donor dye is used to overcome the inherent low pump (532 nm) absorption of these...
Article
Full-text available
In this paper we identify the origin of a novel and singular laser behavior of the hemicyanine dye LDS 722 transversally pumped at 532 nm. With lasing efficiencies as high as 43%, in spite of the fluorescence quantum yields being as low as 0.075, the laser spectra exhibit a finely structured spectral profile, with a periodic modulation with peak se...
Conference Paper
The photophysics and laser action of the organic dye Rhodamine 6G (Rh6G) confined in polymeric nanoparticles, mainly based on copolymers of methyl methacrylate (MMA) and 2-hydroxyethylmethacrylate (HEMA), are analyzed as a function of dye concentration, as well as size of the latex particles. The optical properties of these suspensions are found to...
Article
We establish an efficient strategy to optimize the performance of dye-doped host materials consisting of analyzing in a systematic way the dependence of their Amplified Spontaneous Emission (ASE) efficiency and photostability on the composition and structure of the matrices, selected to specifically avoid the thermal and/or chemical (photooxidation...
Conference Paper
Low threshold and photostable waveguided Random Laser (RL) emission from 580nm to 730nm is reported in organic-inorganic polymer waveguides doped with commercial dyes. The origin of the RL might be in the film roughness.
Article
It has been recently shown that the presence of nanoscatterers up to a certain density, homogeneously distributed in gain media, instead of being detrimental to conventional two-mirror cavity laser efficiency and directionality, may result in an increase of the output energy due to an enlargement in the effective optical path. Here we present a the...
Article
The Variable Stripe Length method is very useful to measure optical gains in thin films. We present analytical expressions to objectively calculate threshold and saturation lengths. Thus, errors arising from subjective estimations are prevented.
Conference Paper
Scattering has always been considered detrimental to conventional lasers, being a source of losses which scramble the directionality and intensity of the output emission [1]. Hence, conventional wisdom requires scattering in laser materials being always kept at the lowest possible level. The opposite is true in the so-called random lasers, which ha...
Article
The use of organic wave-guide lasers based on dye-doped polymers has attracted much attention over the last decade for their applications in integrated photonics. These systems assure wide tunability, high efficiency and easiness of production. A major drawback of these devices is their limited operational lifetime, and any realistic application pa...
Article
Although the variable stripe length (VSL) method has been widely used to measure the optical gain in thin film active media, different nor totally rigorous criteria have yet been used to estimate two important characterization parameters, namely, threshold and saturation lengths, on which the method critically depends. Here we present a formalism w...
Article
Full-text available
Laser emission from leaky waveguides based in dye-doped organic gain media incorporating Polyhedral Oligomeric Silsesquioxanes (POSS) nanoparticles is reported. The samples consist of thin film gain media deposited onto glass substrate defining a planar asymmetric slab waveguide, which does not incorporate any resonant substructure. The presence of...
Article
Optical properties of new materials based on nanometer-sized polyhedral oligomeric silsesquioxanes (POSS) have been of increasing interest for both fundamental and practical reasons, largely because of their novel applications in photonics and electronic devices. [1] The presence of POSS enhances signifi-cantly the thermal, mechanical, and physical...
Conference Paper
We report on efficient and highly photostable solid-state lasers based on dye-doped polymer crosslinked with polyhedral oligomeric silsesquioxane (POSS) nanoparticles. Mechanisms for the improved laser action induced by the POSS presence will be discussed.
Article
Long-lived amplified spontaneous emission (ASE) action is demonstrated in waveguides based in transparent newly synthesized fluorinated polyimides (FPI) doped with laser dye Pyrromethene 597. Relevant parameters to optimize the lasing performance of the guides are the polymer chain density and fluorine content. The guide with the higher fluorine co...
Article
The characteristics of amplified spontaneous emission (ASE) from asymmetric planar waveguides and quasi-waveguides consisting of thin films of poly(methyl methacrylate) incorporating lasing dye pyrromethene 597 deposited onto quartz and glass substrates, respectively, are investigated. The variable stripe length and moving constant stripe methods,...
Conference Paper
The use of organic wave-guide lasers based on dye-doped polymers has attracted much attention over the last decade for their applications in integrated photonics. Here we demonstrate that long-lived laser action can be achieved in two transparent FPI wave-guides (6F6F and 6FIMMDA) doped with laser dye Pyrromethene 597 (PM597). Asymmetric planar wav...
Article
Full-text available
Amplified spontaneous emission from planar waveguides and quasi-waveguides based on Pyrromethene 567-doped poly(methyl methacrylate) thin films deposited onto quartz and glass substrates is investigated. Films with different thickness were prepared and pumped optically at 532 nm with pulses of up to 8 MW/cm(2). Pump thresholds for the onset of ASE...
Article
The aim of the present study was to identify brain electrical activity changes generated by olanzapine (OLZ) in treatment refractory schizophrenics (TRS). 14 paranoid TRS (31.5+/-8.39 years old) were evaluated before and after 8 weeks of OLZ treatment. Psychopathology was evaluated by means of total BPRS and PANSS scores. Resting EEG was recorded i...
Article
Full-text available
This study was conducted in order to compare the EEG patterns of schizophrenics who do not respond to typical neuroleptics with those who do respond under typical neuroleptic medication and a group of controls. Absolute (AP) and relative power (RP), and inter- and intrahemispheric correlations were calculated. Nonresistant schizophrenics showed low...

Citations

... These boronhydride clusters are novel inorganic materials with unique molecular architectures based on 3-dimensional polyhedra [14][15][16]. They possess a relatively sharp room temperature emission band between 400 and 460 nm (depending on the molecular structure and cluster substituents [17][18][19], and they have been shown to be air-stable as well as having good solubility in common solvents and some polymer matrices-all convenient properties for device fabrication. Thus far, the greatest attention has been paid to the cluster anti-B18H22 [13], which gives an emission of blue-purple light at 406 nm stable enough to act as the gain medium in the first borane-based laser [18]. ...
... The predominance of this process over the lasing is disadvantageous from the point of view of the laser device design [3]. The evaluation of acquired lasing action becomes important, due to the multiple approaches that can be used in order to characterize the emission properties [4,5]. As it was presented recently, the determination of the ASE threshold is subjected to measurement uncertainty depending on the applied computational procedure [6]. ...
... One key aspect in this development is a thorough understanding of the photostability of luminescent borane materials in solid-state solution (i.e., in a polymer matrix). Although some work has already been done on their photoluminescence stability in solution [18,21], no such study has yet been made on their solid-state polymer-based materials, the absence of which is a bottleneck in the utilization of any borane-based active layer in OLEDs, where long-term stability of component materials is essential to device operation and market success [22][23][24][25]. ...
... The predominance of this process over the lasing is disadvantageous from the point of view of the laser device design [3]. The evaluation of acquired lasing action becomes important, due to the multiple approaches that can be used in order to characterize the emission properties [4,5]. As it was presented recently, the determination of the ASE threshold is subjected to measurement uncertainty depending on the applied computational procedure [6]. ...
... Typically, the core structure of such dyes is relatively easy to modify through the introduction of specific functional groups at a variety of different positions, allowing fine changes to absorption and emission wavelengths. This opens the way to several applications as biological probes, fluorescent sensors and markers, light-harvesting agents and light emitters in optoelectronic devices (Lv et al., 2018;Sola-Llano et al., 2019;Bismillah and Aprahamian, 2021). ...
... Different pendant moieties can be linked to the BODIPY core to optimize their performances as laser media, application that requires a large Stokes shift to avoid self-quenching, while maintaining a high degree of rigidity in the molecular structure to prevent photo-damage [8][9][10][11][12][13]. Donor-acceptor systems can be realized to enhance resonance energy transfer (RET) mechanisms for light-harvesting antennas [14][15][16][17][18][19] and photovoltaic cells [20][21][22][23][24][25] applications. ...
... To circumvent such restriction, complex and bulky experimental set-ups are required. Therefore, to offset this deficiency, we developed red and NIR dye lasers with improved photonic performance, particularly focused on enhancing the photostability, i.e., benzofuran-fused BODIPYs (Section 2) as laser dyes emitting in the far-red region of the visible spectral region [47] and polyarylated aza-BODIPYs (Section 3) for the NIR spectral region ( Figure 2) [48]. Hereafter, we overview the photophysical and laser properties of these novel BODIPYs designed in our laboratories and compare their photonic performance with commercially available laser dyes working in the same spectral region. ...
... The design, synthesis, and investigation of such compounds are of significant interest in organic chemistry research on photomaterials and biologically active compounds. The chemistry of tetracoordinated borate complexes has been at the forefront of the development of luminescent materials over the last few decades [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Boron compounds exhibit multifunctional photophysical properties and usually demonstrate excellent fluorescence (viz., high quantum yields, remarkable molar extinction coefficients, and large Stokes shifts) both in solution and solid state [21,22]. ...
... Then, we used a moving blade to control the pump stripe length. Lke the previous report 42 , the intensity of the edge-emitted ASE is measured in correspondence to the excitation stripe length. Figure 6a shows the stripe length dependent emission spectra of sample S-II under a pump energy density of 50.6 μJ/cm 2 . ...
... Circularly Polarized Luminescence (CPL), which can provide the chirality information of the electronic excited states [1], has potential applications in CPL lasers [2], optoelectronic devices [3] photoswitches [4], and chiral sensing probes [5]. Therefore, immense efforts have been devoted to develop CPL emissive materials, such as lanthanide complexes [6], polymers [7], supramolecular assemblies [8], and small organic molecules [9,10]. ...