Ladder-type oligo(p-phenylene)s with D–π–A architectures: design, synthesis, optical gain properties, and stabilized amplified spontaneous emission

In this paper, we report optical characteristics of an organic single crystal oligomer 5,5⁗-diphenyl-2,2′:5′,2″:5″,2‴:5‴,2⁗-quinquethiophene (P5T). P5T crystal is a thiophene/phenylene co-oligomer that possesses better charge mobility as well as photoluminescence quantum efficiency (PLQE) as compared to other organic materials. Stimulated emission in P5T is investigated via amplified spontaneous emission (ASE) measurements within broad pump energies ranging from 35.26 to 163.34 µJ/cm2. An Nd-YAG femtosecond-tunable pulsed laser is used as a pump energy source for the ASE measurements of P5T crystals at an excitation wavelength of 445 nm. The ASE spectra exhibit optical amplification in P5T crystals at a 625 nm peak wavelength with a lower threshold energy density (Eth) ≈ 52.64 μJ/cm2. P5T also demonstrates higher optical gain with a value of 72 cm−1, that is calculated by using the variable stripe-length method. The value of PLQE is measured to be 68.24% for P5T. This study proposes potential applications of P5T single crystals in organic solid state lasers, photodetectors, and optical amplifiers.

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Random lasing and amplified spontaneous emission from silk inverse opals: Optical gain enhancement via protein scatterers

Scientific Reports ◽

10.1038/s41598-019-52706-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Muhammad Umar ◽

Kyungtaek Min ◽

Sookyoung Kim ◽

Sunghwan Kim

Keyword(s):

Spontaneous Emission ◽

High Surface ◽

Optical Gain ◽

Amplified Spontaneous Emission ◽

Biological Tissues ◽

Light Sources ◽

Inverse Opal ◽

Random Lasing ◽

Protein Film ◽

Gain Enhancement

Abstract Gain amplification and coherent lasing lines through random lasing (RL) can be produced by a random distribution of scatterers in a gain medium. If these amplified light sources can be seamlessly integrated into biological systems, they can have useful bio-optical applications, such as highly accurate sensing and high-resolution imaging. In this paper, a fully biocompatible light source showing RL and amplified spontaneous emission (ASE) with a reduced threshold is reported. Random cavities were induced in a biocompatible silk protein film by incorporating an inverse opal with an inherent disorder and a biocompatible dye for optical gain into the film. By choosing the appropriate air-sphere diameters, clear RL spikes in the emission spectra that were clearly distinguished from those of the ASE were observed in the silk inverse opal (SIO) with optical gain. Additionally, the RL output exhibited spatial coherence; however, the ASE did not. The high surface-to-volume ratio and amplification of the SIO led to highly efficient chemosensing in the detection of hydrogen chloride vapor. Moreover, SIO could be miniaturized to be made suitable for injection into biological tissues and obtain RL signals. Our results, which open the way for the development of a new generation of miniaturized bio-lasers, may be considered as the first example of engineered RL with biocompatible materials.

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Design, synthesis and amplified spontaneous emission of 1,2,5-benzothiadiazole derivatives

Journal of Materials Chemistry C ◽

10.1039/c9tc03148k ◽

2019 ◽

Vol 7 (32) ◽

pp. 9996-10007 ◽

Cited By ~ 4

Author(s):

Raúl Martín ◽

Pilar Prieto ◽

José R. Carrillo ◽

Ana M. Rodríguez ◽

Abel de Cozar ◽

...

Keyword(s):

Spontaneous Emission ◽

Amplified Spontaneous Emission ◽

Design Synthesis

The design, synthesis and evaluation of the amplified spontaneous emission (ASE) properties of a series of arylalkynyl-benzo[c][1,2,5]thiadiazole (BTD) and [1,2,5]thiadiazolo[3,4-g]quinoxaline (TDQ) derivatives are described.

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