Article
Materials Science, Multidisciplinary
Qi Wei, Ruihong Duan, Qi Zhang, Linghai Xie, Ruidong Xia, Yuanping Yi, Jeremie Leonard, Stefan Haacke, Juan Cabanillas-Gonzalez, Yan Qian, Wei Huang
Summary: By designing compounds with tunable electronic transition characters and studying their vibrational modes using computational calculations and experiments, this study provides guidelines for the rational design of efficient organic laser materials. The results show that the coupling of high wavenumber vibrational modes to pure LE states is essential for optical gain, while broad excited-state absorption overwhelming stimulated emission is favored when HLCT or CT states are coupled to low frequency vibrational modes.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Optics
N. Soniya, S. Aswathy, G. S. Anagha, K. Shadak Alee
Summary: The role of coupling coefficients in asymmetric coupled waveguides is crucial for achieving a low threshold of amplified spontaneous emission (ASE). Our theoretical investigation reveals that the coupling coefficient carries the asymmetry according to the symmetry of the structure, with symmetric and asymmetric coupled waveguides having different coefficients. Experimentally, we demonstrate how unequal coefficients affect energy transfer and present the correlation between the value of the coupling coefficient and the observed threshold of the acceptor ASE for optimizing the coupled waveguide as an efficient optical amplifier.
Article
Chemistry, Applied
Hao Sun, Ming Li, Lei Shang, Lu Wang
Summary: This study constructs an efficient single benzene ring solid-state emitter by utilizing aggregation-induced emissions (AIE) and excited-state intramolecular proton transfer reaction (ESIPT), achieving high solid-state emission from polycrystalline states. While there are many reports of small molecules exhibiting amplification spontaneous emission laser properties, there are few reports of single benzene rings exhibiting laser properties.
Article
Biochemistry & Molecular Biology
Stefania Milanese, Maria Luisa De Giorgi, Luis Cerdan, Maria-Grazia La-Placa, Nur Fadilah Jamaludin, Annalisa Bruno, Henk J. Bolink, Maksym V. Kovalenko, Marco Anni
Summary: Nowadays, the search for novel active materials for laser devices is progressing rapidly. This study investigates the dependence of amplified spontaneous emission (ASE) threshold on the method used to determine it in different materials, and proposes a standard procedure to properly characterize the ASE threshold.
Article
Chemistry, Multidisciplinary
Zuofang Feng, Tao Hai, Lulu Zhang, Yilong Lei
Summary: In this study, a facile solution assembly route is developed to achieve organic microwires (MWs) with fractal branching patterns. The thermodynamically favored alpha-OPV-A allows for the formation of fractal MWs with tailored branching densities and hierarchies. It is found that both coassembly and two-step seeded growth can be utilized to achieve single- and multisite growth of the branching alpha-OPV-A MWs. The aligned alpha-OPV-A MW array demonstrates multichannel optical gain medium properties and low-threshold amplified spontaneous emission (ASE).
Review
Optics
Nannan Feng, Min Lu, Siqi Sun, Anqi Liu, Xiaomei Chai, Xue Bai, Junhua Hu, Yu Zhang
Summary: In recent years, practical engineering applications such as fiber-optic gyroscope, wavelength division multiplexing, and optical coherence tomography have put forward higher requirements on light sources due to the rapid development of military, optical communication, biological imaging, and other fields. Amplified spontaneous emission (ASE) light source has become an excellent candidate due to its advantages such as suitable bandwidth, low coherence, and high power. This review analyzes the principle of the ASE effect, summarizes the optical gain properties of various gain materials and different structural types of electrically pumped ASE devices, and prospects the development of new ASE light-emitting devices integrated with high-gain materials and low-cost structures.
LASER & PHOTONICS REVIEWS
(2023)
Article
Optics
Chaochao Qin, Shichen Zhang, Zhongpo Zhou, Tao Han, Jian Song, Shuhong Ma, Guangrui Jia, ZhaoYong Jiao, Zunlue Zhu, Xumin Chen, Yuhai Jiang
Summary: In this study, a novel quasi-2D Ruddlesden-Popper perovskite based on 2-thiophenemethylammonium (ThMA) is synthesized using a facile solution-processed method. Additionally, an anti-solvent treatment method is proposed to tune the phase distribution and orientation of the thin films, resulting in improved energy transfer efficiency and carrier population transfer. These findings lead to the realization of low-threshold lasers and amplified spontaneous emission.
Article
Chemistry, Multidisciplinary
Yin Liang, Qiuyu Shang, Meili Li, Shuai Zhang, Xinfeng Liu, Qing Zhang
Summary: A solvent recrystallization strategy was proposed to reduce the number of pinholes in perovskite films, resulting in amplified spontaneous green emissions with a low threshold and high net modal gain. The reduced threshold is attributed to low propagation loss and suppressed Auger recombination, which are achieved by forming a pinhole-free surface and enlarging grain size.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Polymer Science
Zhiqiang Cheng, Xin Wang, Jingcheng Zhao, Shuai Wang, Xiaofu Wu, Hui Tong, Lixiang Wang
Summary: CPs with selenium-containing phenoselenazine unit in conjugated backbones exhibit clear room-temperature phosphorescent emission, with high phosphorescence quantum yields and lifetimes. These CPs can also be used for oxygen detection and demonstrate significant phosphorescent signal amplification compared to their molecule counterpart.
Article
Polymer Science
Zhiqiang Cheng, Xin Wang, Jingcheng Zhao, Shuai Wang, Xiaofu Wu, Hui Tong, Lixiang Wang
Summary: Purely organic room-temperature phosphorescent (RTP) polymers with good processability and flexibility have been prepared by introducing a selenium-containing phenoselenazine unit into conjugated backbones. These RTP CPs exhibit phosphorescence lifetimes ranging from microseconds to milliseconds and phosphorescence quantum yields of up to 17.2% in film states, which is the highest value for metal-free CPs. Additionally, these RTP polymer films demonstrate significant phosphorescent signal amplification, with a Stern-Volmer quenching constant (K-SV) value 250 times higher than that of their molecule counterpart.
Article
Nanoscience & Nanotechnology
Modestos Athanasiou, Paris Papagiorgis, Andreas Manoli, Caterina Bernasconi, Maryna Bodnarchuk, Maksym Kovalenko, Grigorios Itskos
Summary: Solution-processed lasers are cost-effective and compatible with a wide range of photonic resonators, allowing for mass production of flexible, lightweight, and disposable devices. Lead halide perovskite nanocrystals (LHP NCs) show great potential as active mediums for solution-processed lasers due to their optical gain properties and defect-tolerant nature. By optimizing the polymer mirrors, resonators with high Q-factors can be produced, supporting amplified spontaneous emission in the green spectrum under continuous wave excitation with low thresholds. The CsPbBr3 NCs embedded in polymeric Bragg reflectors show promising results in terms of output intensity amplification and radiative rate increase when compared to reference microcavity structures.
Article
Chemistry, Multidisciplinary
Yang Li, Hang Hu, Ahmed Farag, Thomas Feeney, Isabel Allegro, Uli Lemmer, Ulrich W. Paetzold, Ian A. Howard
Summary: Perovskite gain materials can sustain continuous-wave lasing at room temperature. However, electrical stimulation supplementing optical has reduced gain performance in the past. In this study, researchers found that the addition of an electric field can turn on/off the amplified spontaneous emission (ASE) in a CsPbBr3 perovskite light-emitting diode (LED), and a positive bias voltage leads to a reduction in the optical ASE threshold.
Article
Optics
Yiming Shen, Bo Wu, Bin Zhang, Feng Chen
Summary: We present the design and fabrication process of helical cladding waveguides in Nd:YAG crystal using femtosecond laser direct writing. These waveguides exhibit excellent guiding properties and low bending losses when characterized through end-face coupling at 1064 nm. The helical waveguide structure achieves a minimum bending loss of 0.55 dB/cm and allows for mode modulation by altering helix geometry parameters. The polarization dependence of these waveguides is kept at a relatively low level. Additionally, an S-bend waveguide is demonstrated, indicating increased bending loss due to enhanced interaction between light and boundaries in the helical structure. This study paves the way for the fabrication of photonic circuits with complex 3D structures in crystals.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Geetha Bolla, Qing Liao, Saeed Amirjalayer, Zeyi Tu, Shaokai Lv, Jie Liu, Shuai Zhang, Yonggang Zhen, Yuanping Yi, Xinfeng Liu, Hongbing Fu, Harald Fuchs, Huanli Dong, Zhaohui Wang, Wenping Hu
Summary: Through halogen-bonded cocrystallization, controllable molecular packing motifs can be achieved in organic semiconductors, leading to increased radiative decay rate and decreased ASE threshold. Cocrystallization is a powerful approach that is fundamentally important for the development of organic ASE and lasing materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Materials Science, Multidisciplinary
Sheng Wang, Jiahao Yu, Haiqiao Ye, Mingbo Chi, Heng Yang, Haihui Wang, Fan Cao, Wenqiang Li, Lingmei Kong, Lin Wang, Rui Chen, Xuyong Yang
Summary: In this study, a Lewis soft base ligand was used to balance the reactivity difference between Zn and Cd precursors, crafting a thick gradient alloyed shell with gradually increased potential barrier in blue quantum dots. This approach successfully restricts charge carriers tunneling and smooth the confinement potential, leading to blue QDs with a long lifetime and low threshold, showing superior performance compared to existing blue-emitting nanocrystals.
ADVANCED OPTICAL MATERIALS
(2021)
