Solid-state Dye Laser Research Articles

Polymeric laser rods based on modified poly(methyl methacrylate) matrix synthesized by FeIII complex catalyzed atom transfer radical polymerization with enhanced optical gain and Photostability

AbstractThe investigation of fabricating ultra‐compact solid‐state dye laser (SSDL) using N'N‐dimethylformamide (DMF) modified poly(methyl methacrylate) (PMMA) as the polymeric matrix was carried out. Atom transfer radical polymerization (ATRP) was introduced to manipulate the polymerization process of PMMA. By adjusting the additive amount of the FeIII complex (mixture of FeCl3 and 2,2’‐Bipyridyl (bPy)), the polymerization degree of PMMA was coordinated to gain better amplified spontaneous emission (ASE) properties of the embedded laser dye, Lumogen Orange 240 (LO). The ASE threshold of the FeIII complex catalyzed sample decreased as high as ~75%, from 225.3 ± 11.2 μJ cm−2 to 57.2 ± 2.9 μJ cm−2, comparing to that measured in common PMMA matrix. Additionally, a secondary dye, Stilbene 420 was added in the system for sharing excess excitation energy and oxidization damage, to overcome the photostability problem caused by the oxygen‐rich solvent, DMF. The operational lifetime of the resulted sample increased 200%, to the similar level of that without DMF component. Finally, by mechanical polishing and coating a thin film of silver at one end of the PMMA rod, an analogous Fabry‐Perot resonator was structured within the rod. Decent laser emission was obtained from the resulted SSDL without complex external cavities.

Mathematical model for estimating the characteristics of a layered solid-state dye laser with optical pumping of the active environment

Mathematical model for estimating the characteristics of a layered solid-state dye laser with optical pumping of the active environment

Design and construction of tunable solid-state dye laser pumped by flashlamp

Over the past six decades, dye laser technology has improved substantially. The usage of solid matrices containing laser dyes is becoming more and more popular as a viable substitute for the traditional liquid dye solutions. In this research, we designed and built a tunable solid dye laser device which consists of three main parts. (i) The active material producing the laser beam, which is a polymer rod [glycidyl methacrylate (GMA) polymer] doped with the laser dyes pyrromethene 597 (PM-597) or Nile blue (Nb-690). (ii) The pumping source is xenon linear flashlamp driven by a homemade power supply. (iii) Two broadband mirrors providing the optical feedback stable optical resonator. The properties of the gain medium and hence the laser emission characteristics were determined, and the results showed the efficiency of the homemade tunable solid dye laser device, that is suitable for a variety of applications.

A low-cost, highly efficient solid-state dye laser made of Rhodamine B dopped photopolymer host cured by mercury or halogen lamp

In this work, we designed a rod shape solid-state laser gain media (GM) that can produce amplified spontaneous emission (ASE) in the 630–670 nm region. The GM is made with Rhodamine B (RhB) dissolved in acetone mixed with commercially available rapid photopolymer (PP) resin that predominately (80 %) contains 3-nitro-9-octyl-9H-carbazole (NOCB) and solidified with mercury or halogen lamp. We used a solid-state matrix laser (SSL) rod of RhB embedded NOCB. The results showed that the photoluminescence (PL) of SSL was at approximately 630 m, and the absorption peak was at 575 nm. The concentration of the RhB in acetone was varied from 25 mg/ml to 100 mg/ml and mixed in a 1:10 ratio volume/weight (v/w). GM could be pumped transversely using 355 nm (3rd Harmonic of Nd: YAG) or 405 nm diode laser or a UV lamp. The GM was initially designed with the aim to be pumped using 532 nm since the resin solidified using UV and blue light irradiation. Supersizing, we found that after complete polymerization, optical pumping using 355 nm can be employed to produce ASE. The main advantage of using these SSL are (i) ease of manufacturing, (ii) simplicity to scale up, (iii) low cost, and (iv) 3D printer compatibility. It also has potential applications in the military, science, and medicine, especially facial rejuvenation.

Transparent Wood Biocomposite of Well-Dispersed Dye Content for Fluorescence and Lasing Applications.

Aggregation-induced quenching often restricts emissive performance of optically active solid materials with embedded fluorescent dyes. Delignified and nanoporous wood readily adsorbs organic dyes and is investigated as a host material for rhodamine 6G (R6G). High concentration of R6G (>35 mM) is achieved in delignified wood without any ground-state dye aggregation. To evaluate emissive performance, a solid-state random dye laser is prepared using the dye-doped wood substrates. The performance in terms of lasing threshold and efficiency was improved with increased dye content due to the ability of delignified wood to disperse R6G.

Multimode laser emission from BODIPY dye-doped polymer optical fiber

We report the fabrication and investigations of lasing properties of dipyrromethene boron difluoride (BODIPY) dye-doped polymer optical fibers (DDPOFs) using two different pumping schemes. Here, we have explored BDIPA dye, a π-extended BODIPY derivative as the gain medium. A Q-switched Nd:YAG laser operating at 532 nm was used, as the pump source for the lasing studies. Stripe illumination using a cylindrical lens produces amplified spontaneous emission (ASE) in the fiber whereas a multimode laser emission at a low lasing threshold of 50 μJ was observed by spot illumination technique using a convex lens. The cylindrical surface of the optical fiber acts as a cavity and it provides the necessary optical feedback for the gain medium resulting in the observed lasing properties. The photostability of the fiber was investigated at higher pump energy of 2 mJ using a convex lens. Excellent results such as very low lasing threshold, high cavity Q-factor and photostability were observed for the fabricated BDIPA DDPOF, clearly indicating the use of the BDIPA dye as a prominent lasing material in solid-state dye lasers.

Highly photo-stable, kHz-repetition-rate, diode pumped circulation-free liquid dye laser with thermal lens management

Liquid dye lasers have long been considered as ideal tunable laser sources in the visible range but are bulky, expensive, and require a complex system for dye circulation. Here, we present a system that relies on a low-cost blue laser diode as the pump source and a sealed dye cell with no flowing circuitry, resulting in a device that combines the convenience and size of a solid-state device with the stability of a liquid organic laser. A very high photo-stability is obtained (up to 1.2 × 109 pulses or 12 days at 1 kHz), which is five orders of magnitude higher than a solid-state dye laser operated in similar conditions. The number of pulses obtainable at low repetition rates is found to be limited by molecular self-diffusion and, hence, related to the total cuvette volume. In contrast, the repetition rate is limited to a few kHz, which suggests that thermal effects play a bigger role than triplet population effects. Thermal effects participate in the suppression of lasing through the buildup of a strong negative thermal lens; correcting the non-aberrant part of this thermal lens by resonator design enables the repetition rate to be pushed up to 14 kHz with possible further optimization. This work shows a route for building off-the-shelf, compact, low-cost, and convenient tunable pulsed lasers in the visible range that have superior stability over organic solid-state lasers.

Organic random laser generation by stimulated cascaded four-wave mixing

Our study investigated the nonlinear lasing properties of a solid-state dye laser. Laser emission was provided by light amplification in static disordered nanostructures with the gain based on a xanthene dye-functionalized epoxy resin polymer. The emission spectrum was found to be reproducible at each near-threshold excitation pulse. We consider that this spectrum results from a non-degenerate cascaded four-wave mixing in the investigated gain medium. The pump beams were generated simultaneously in the bulk isotropic active medium by single-shot excitation on the nanosecond time scale. The downshift and upshift modes were generated via their coherent pump beams. To our knowledge, this type of stimulated highly nondegenerate cascaded four-wave mixing in the visible spectral range (486 nm – 680 nm) has not been experimentally demonstrated before in a random gain medium.

Sensitized fluorescence and superluminescence of a dye in a functional chitosan–gelatin matrix

A method for the formation of a functional biopolymer matrix based on specific mixing of chitosan and gelatin is proposed. It makes it possible to obtain the binding complexes of organic dyes such as eosin (energy donor) and rhodamine C (acceptor) with chitosan that are advantageous for the realization of inductive-resonant electron excitation energy transfer between these dyes. An efficient sensitized steady-state fluorescence of rhodamine C and superluminescence of this dye under pulsed excitation were observed in this system. The obtained results can be used for the development of two-component solid-state dye lasers.

A photoacoustic finder fully integrated with a solid-state dye laser and transparent ultrasound transducer

The standard-of-care for evaluating lymph node status in breast cancers and melanoma metastasis is sentinel lymph node (SLN) assessment performed with a handheld gamma probe and radioisotopes. However, this method inevitably exposes patients and physicians to radiation, and the special facilities required limit its accessibility. Here, we demonstrate a non-ionizing, cost-effective, handheld photoacoustic finder (PAF) fully integrated with a solid-state dye laser and transparent ultrasound transducer (TUT). The solid-state dye laser handpiece is coaxially aligned with the spherically focused TUT. The integrated finder readily detected photoacoustic signals from a tube filled with methylene blue (MB) beneath a 22 mm thick layer of chicken tissue. In live animals, we also photoacoustically detected both SLNs injected with MB and subcutaneously injected melanomas. We believe that our radiation-free and inexpensive PAF can play a vital role in SLN assessment.

Aктивні середовища на основі поліуретану, допованого бінарною сумішшю барвників

Subject and Purpose. The article is concerned with the spectral-luminescent and lasing characteristics of the radiation from solid-state active media based on polyurethane activated by a binary mixture of dyes. The purpose of these studies is to demonstrate a possibility of the spectral range expansion of the emission from solid-state dye lasers with polyurethane active elements. Methods and Methodology. Specially prepared samples of polyurethane active media having the same donor (Rhodamine 6G) concentration but various acceptor (Sulforhodamine 101) concentrations are experimentally studied for their spectral-luminescent and lasing characteristics. Results. The main spectroscopic characteristics of Rhodamine 6G and Sulforhodamine 101 in polyurethane have been measured, the nonradiative energy transfer parameters in this molecular pair estimated. It has been demonstrated that the matrix emission spectrum can be purposefully transformed by selection of relative concentrations of dyes in the mixture. In a broadband resonator, either a single- or two-band emission with different positions and various intensities of spectral bands is observed depending on the acceptor concentration. In a dispersive resonator under the same conditions, the tuning range of the lasing spectrum expands and extends to the longer wavelengths. Conclusion. The prospects of using donor-acceptor dye mixtures for improving spectral characteristics of polyurethane active elements in solid-state dye lasers have been confirmed. It has been shown that signatures of the emission characteristics of these media are governed by the mechanism of the excitation energy transfer between dye molecules. Lasing has been obtained on polyurethane matrices with the emission wavelength tuning throughout the “green-red” region of the spectrum.

Comparative Study of Coumarin-120 (C-120) and Stilbine-3 (STB-3) Laser Dyes Doped in Sol-Gel Glasses

In 1967 the first work in solid state dye laser was performed by doping rhodamine dyes in Polymethylmethacrylate (PMMA) materials. Since then some materials like various types of polymers, co-polymers, poly composite glasses have been used as host matrices for doping different laser dyes. Polymers suffer from limited mechanical and thermal stability. Hence glasses can be the alternative hosts. However, because of high processing temperature leading to permanent destruction of dye molecules, the conventional glass preparation technique is not suitable for the introduction of organic laser dyes. This difficulty can be overcome by introducing the laser dye molecules in sol-gel glass which is prepared at low temperature. Recent work with sol-gel glasses shows that these glasses may prove to be better materials compared to polymeric materials because glasses being hard, best optically transparency in Near UV-UV and Visible region and show better photostability. In this research work we reported, comparative study of the photophysical properties of Coumarin-120 (C-120) belonging to 7-aminocoumarin family having two hydrogen atoms attached to the N atom at the 7-position, with Stilbene-3 (STB-3) in three types of HCl catalyzed SiO2 sol-gel matrices prepared by Method I, Method II and Method III respectively.

In Vivo Dual-Modal Photoacoustic and Ultrasound Imaging of Sentinel Lymph Nodes Using a Solid-State Dye Laser System.

Photoacoustic imaging (PAI) is being actively investigated as a non-invasive and non-radioactive imaging technique for sentinel lymph node (SLN) biopsy. By taking advantage of optical and ultrasound imaging, PAI probes SLNs non-invasively with methylene blue (MB) in both live animals and breast cancer patients. However, these PAI systems have limitations for widespread use in clinics and commercial marketplaces because the lasers used by the PAI systems, e.g., tunable liquid dye laser systems and optical parametric oscillator (OPO) lasers, are bulky in size, not economical, and use risky flammable and toxic liquid dyes. To overcome these limitations, we are proposing a novel dual-modal photoacoustic and ultrasound imaging system based on a solid-state dye laser (SD-PAUSI), which is compact, convenient, and carries far less risk of flammability and toxicity. Using a solid-state dye handpiece that generates 650-nm wavelength, we successfully imaged the MB tube positioned deeply (~3.9 cm) in chicken breast tissue. The SLNs were also photoacoustically detected in the in vivo rats beneath a 2.2-cm-thick layer of chicken breast, which is deeper than the typical depth of SLNs in humans (1.2 ± 0.5 cm). Furthermore, we showed the multispectral capability of the PAI by switching the dye handpiece, in which the MB-dyed SLN was selectively highlighted from the surrounding vasculature. These results demonstrated the great potential of the SD-PAUSI as an easy but effective modality for SLN detection.

RETRACTED ARTICLE: Optical spectroscopic analysis of bandpass filter used for laser protection based on cobalt phosphate glass

A protection glass against laser beam was fabricated from a cobalt oxide-doped copper phosphate glass with series of 40P2O5–(20−x) Na2O–38ZnO– xCo3O4–1CuO in the molar ratio with x = 1, 2, 3, 4 and 5 using a conventional glass casting and quenching technique. The density was measured by Archimedes method, and the molar volume was calculated. Increasing the heavy element, cobalt oxide in a glass composition causes an unusual phenomenon between the density and molar volume that they have the same trend. The XRD technique has been used to investigate the glass systems and prove the complete glass state of the systems. Optical spectroscopic analysis from the transmittance data of the glass filter showed that these filters had a single band pass with a double band stop in the UV, visible and IR, which covers the region that is used in some laser protection glass like organic dye lasers, polymer lasers, solid-state dye lasers, excimer, quadrupled Nd:YAG laser and quintupled Nd:YAG laser. This can be used for a glass laser safety protection.

All-polymer distributed Bragg reflector laser self-heals to original output power

Doping certain polymers with rhodamine 6g allows a solid-state dye laser to recover its original output power after photodegradation.

Tunable polymer dye laser pumped by two 513 nm diodes

We demonstrate a tunable solid-state polymer dye laser with quasi-longitudinal pumping by two green (λ = 513 nm) laser diodes. Tuning curves with a maximum efficiency of 13% were attained, using a plate of crystalline quartz (Lyot filter) for wavelength selection. In a three-mirror cavity with partial compensation of astigmatism, the total tuning range was 62 nm (from 545 nm to 607 nm) for pyrromethene dyes: PM567, PM580 and PM597. The best results were achieved with active elements based on Pyrromethene 580 laser dye in a mixture of polyvinyl butyral or a copolymer of butylmethacrylate and methacrylic acid (ratio 9:1) with the addition of 30% dibutylsebacinate as a plasticizer.

A High-Power and Highly Efficient Semi-Conductor MOPA System for Lithium Atomic Physics

A compact and highly efficient 670.8-nm semi-conductor master oscillator power amplifier (MOPA) system, with a unique optical design, is demonstrated. The MOPA system achieves a continuous-wave (CW) output power of 2.2 W, which is much higher than commercial products using semi-conductor devices. By comparing solid state lasers and dye lasers, higher wall-plug efficiency (WPE) of 20 % is achieved. Our developed laser system also achieves spectral line-width of 0.3 pm (200 MHz) and mode-hop free tuning range of 49 pm (32.6 GHz), which is very suitable for experiments of lithium atomic physics at several-watt power levels, such as Bose-Einstein condensation (BEC) and isotope absorption spectroscopy.

Two-Directional Tuning of Distributed Feedback Film Dye Laser Devices.

We demonstrate a two-directional tuning method of distributed feedback (DFB) film dye laser devices to achieve high quality lasing and a large tuning range. In this work, we proposed a simple method to fabricate a continuous tunable solid-state dye laser on a flexible Polydimethylsiloxane (PDMS) film. In order to obtain stable and tunable output lasing, the stretching property of the gelatine host was improved by mixing with a certain ratio of glycerol to prevent DFB cavity destruction. We employed two different tuning strategies of the DFB film dye lasers, by stretching the PDMS film in two perpendicular directions, and a nearly 40 nm tuning range in each direction was achieved. The laser device maintained single mode lasing with 0.12 nm linewidth during the tuning process. The reported tunable DFB film dye laser devices have huge potential as coherent light sources for sensing and spectroscopy applications.

Spectral evolution of distributed feedback laser of gold nanoparticles doped solid-state dye laser medium

Characteristics of suppressed relaxation oscillation of a distributed feedback dye laser (DFDL) based on the energy transfer process in a mixture of spherical gold nanoparticles-doped solid-state polymethylmetacrylate dissolved 4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran dye was theoretically and experimentally studied. Single pulse generation regime of the DFDL can be obtained with a suitable gold nanoparticle concentration and ratio of pump power over lasing threshold. Numerical analysis and experimental approach showed that in this regime, the first-pulse laser pulsewidth is rather unchanged while varying the gold nanoparticles concentration in the range of 2.0 × 109–2.0 × 1010 par cm−3. The enhancement of first pulse and the suppression of the secondary pulses by bi-direction energy transfer of spherical gold nanoparticles were experimentally observed.

Methacrylate-Based Copolymers for Polymer Optical Fibers.

Waveguides made of poly-methyl-methacrylate (PMMA) play a major role in the homogeneous distribution of display backlights as a matrix for solid-state dye lasers and polymer optical fibers (POFs). PMMA is favored because of its transparency in the visible spectrum, low price, and well-controlled processability. Nevertheless, technical drawbacks, such as its limited temperature stability, call for new materials. In this work, the copolymerization technique is used to modify the properties of the corresponding homopolymers. The analytical investigation of fourteen copolymers made of methyl-methacrylate (MMA) or ethyl-methacrylate (EMA) as the basis monomer is summarized. Their polymerization behaviors are examined by NMR spectroscopy with subsequent copolymerization parameter evaluation according to Fineman-Ross and Kelen-Tüdös. Therefore, some r-parameter sets are shown to be capable of copolymerizations with very high conversions. The first applications as high-temperature resistant (HT) materials for HT-POFs are presented. Copolymers containing isobornyl-methacrylate (IBMA) as the comonomer are well-suited for this demanding application.