Organic thin film lasers and some of their applications

Recently, there has been an increase in interest in the creation of photoexcited organic thin film lasers, including those based on polymers with semiconducting properties, since intensive work is currently underway to create injection organic lasers and the first results have been obtained. Unlike solid-state lasers based on inorganic materials, organic lasers use a thin layer of organic molecules to amplify light. One of the main advantages of organic lasers is that they can cover the entire visible wavelength range

Amplification of spontaneous emission on sodium D-lines using nonresonance broadband optical pumping

We describe experiments on the excitation of amplified spontaneous emission on the D-lines of sodium (D2 = 588.9 nm; D1 = 589.6 nm) with longitudinal optical pumping with a large detuning from the D2 line toward shorter wavelengths. The radiation spectra are measured, showing gain on both lines, at a Na concentration of (1–5) × 1014 cm–3, buffer gas (helium) pressure of 600 Torr at the working temperature, and pumping power density of more than 1.5 MW/cm2. The time characteristics show that the output radiation varies versus the concentration of sodium atoms in the active medium. The dependences of radiation absorption at the D-lines of sodium on the concentration of Na atoms and buffer gas pressure are given

Tunable organic solid state laser

The creation of spectrally narrow tunable wavelength over a wide range, having a small loss in laser generation power is an actual problem in modern laser physics. Lasing characteristics (FWHM) of solid state active media based on Chromen 3 (Ch-3) in polymethylmethacrylate (PMMA) are investigated. Patterns of changing the lasing characteristics depending on resonator’s geometric parameters. It is demonstrated that the wavelength of solid state active media in specific resonator's geometric parameters can be narrowed to the lowest value possible. Such laser properties are known for wide application in laser spectroscopy

Optical spectra and laser induced fluorescence of bisphenol A

Bisphenol A (BPA) is a known disruptor of the human endocrine system. Our research has been carried out aimed at identifying the features of laser induced fluorescence of BPA at different pH and the properties of the solvent for the development of a method for the detection of a toxicant in biological systems. The spectral characteristics of BPA are very sensitive to the excitation wavelength. We used excitation wavelengths at 266, 355, and 532 nm from a YAG–Nd3 + laser LQ 529

Fluorescent chemical sensors in laser generation mode

Investigations aimed on the detection of harmful substances for human life are very exist. Nitrocompounds are included among many. Among numerous chemical compounds contaminating the environment, a prominent place is occupied by nitroaromatic compounds, many of which enter the composition of explosive materials. They are contained in industrial waste and are toxic for living organisms. Of the wide variety of methods for detecting chemicals, method based on the quenching of fluorescence of organic compounds is a simple and fairly sensitive

Tunable solid-state dye laser doped by Chromen-3 and PM-567

Solid-state active laser media using PMMA matrices doped by Chromene-3 and PM-567 were created. Their lasing and spectral properties are investigated. Fluorescence bandwidth is wide enough for tunability (near 40 nm full-width on the half maximum - FWHM). The photostability is number of the pulses in one dot needed to decrease efficiency twice – near of 3*105 pulses are obtained. The obtained data lead to the development of the tunable solid-state laser on the basis of the investigated LAE demanded in medicine

Solvent effect on the spectra of methylene green and methylene blue

This investigation focuses on dyes that differ only in the nitro substituent. The NO2 group leads to a strong hardening of the fluorescence at 298 K. In methylene green (MG) the excitation energy migrates to the system of triplet states. This nonradiative process causes the MG fuorescence absent or too low compared to methylene blue (MB). Moreover, laser-induced fluorescence is completely absent for MG in the investigated solvents. However, at liquid nitrogen temperature, we recorded fluorescence for MG in ethanol 250 times higher than at room temperature and phosphorescence too. The intensity of the MB fluorescence band in ethanol at 77 K is 6 times higher than at room temperature. According to the results of this study, the lifetime in the excited state decreases in the following order: isopropanol > acetonitrile≈ethanol≈dimethyl sulfoxide > > water for MG and chloroform > acetonitrile≈ethanol≈dimethyl sulfoxide > > water≈isopropanol for MB. In addition, MG has phosphorescence in ethanol at 780 nm and in chloroform at 810 nm