Article
Engineering, Electrical & Electronic
Victor Kopp, Jongchul Park, Jonathan Singer, Daniel Neugroschl, Azriel Z. Genack
Summary: By passively combining sixty-one lasing fiber channels in a monolithic optical resonator array, researchers achieved an output power above 200W at a two-micrometer wavelength. The study found that the central intensity enhancement improves as the number of channels increases, which is an important step towards a passively combined multichannel all-solid-state laser system.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Optics
Nideesh Padiyakkuth, Rodolphe Antoine, Nandakumar Kalarikkal
Summary: The development of novel polymer nanofiber-based photonic devices has led to improved optical materials, extremely appealing for random lasers. Electrospun polymer fibers have been proposed as convenient materials for random lasers, offering a versatile and low-cost strategy for developing new scattering materials. In this study, electrospun PVDF polymer mats doped with R6G dye were utilized to observe the transition from amplified spontaneous emission to lasing with coherent feedback by increasing the gain concentration.
JOURNAL OF LUMINESCENCE
(2022)
Article
Chemistry, Multidisciplinary
Binghao Yu, Qiang Hao, Cheng Tang, Kangwen Yang, Huaixi Chen, Wanguo Liang, Heping Zeng
Summary: In this paper, we demonstrate the creation of a femtosecond green laser using a MgO-doped periodically poled lithium niobate crystal pumped by a home-made Yb-doped MOPA laser system. The laser system produces stable laser pulses with high conversion efficiency and low intensity fluctuations, making it suitable for two-photon photopolymerization applications.
APPLIED SCIENCES-BASEL
(2022)
Article
Optics
Anirban Sarkar, B. N. Shivakiran Bhaktha
Summary: This study reveals a replica symmetry breaking phase transition independently in both coherent and incoherent parts of intensity. The incoherent component contributes more to mode coupling and significantly determines the decay profile of lasing intensity.
Article
Optics
Xiaobo Xue, Qi Jiang, Fufei Pang, Jianxiang Wen, Wei Chen, Xianglong Zeng, Liang Zhang, Heming Wei, Tingyun Wang
Summary: An all-fiber fiber coupler was developed for amplification of orbital angular momentum (OAM) modes by side-polishing and bonding a ring-core erbium-doped fiber (RC-EDF) and a pre-tapered side-polished single-mode fiber (SMF). The pumping laser was efficiently coupled into the RC-EDF from the SMF for the selected phase-matching condition at 976 nm, and the 1st to 3rd-order OAM mode signals were transmitted with low insertion loss in the RC-EDF over a wide wavelength range. The proposed side-polished pumping coupler technique enables high-order OAM mode amplification, making it promising for all-fiber optical amplifiers in high-capacity modal-division multiplexing fiber communication systems.
Article
Engineering, Electrical & Electronic
Shijie Fu, Xiushan Zhu, Jie Zong, Michael Li, Ivan Zavala, Valery Temyanko, Arturo Chavez-Pirson, Robert A. Norwood, Nasser Peyghambarian
Summary: In this experiment, a single-frequency distributed Bragg reflector fiber laser at 915 nm was achieved using a 2.5-cm Nd3+-doped phosphate fiber, resulting in an output power of 13.5 mW at an absorbed pump power of 240 mW. The experimental results indicate that Nd3+-doped phosphate glass fiber is more efficient than Nd3+-doped silica glass fiber for single-frequency laser operation in the 900 nm wavelength range.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Hai-Yue Pang, Jia-Teng Zheng, Zhao-Yun Li, Huan Liu, Zhi-Yong Tao, Ya-Xian Fan
Summary: This paper presents a dual wavelength erbium-doped random fiber laser based on a micro air cavity. The laser exhibits a low threshold of about 15 mW and a high optical signal to noise ratio of over 40 dB. By adjusting the length of the air cavity, a stable dual wavelength output with a controllable separation from 2.5 nm to 20.2 nm is achieved. The measured fluctuation in lasing wavelengths and output powers are both very small, indicating a highly stable performance. This laser is expected to fulfill the increasing demands of applications such as optical communication, lidars, and fiber sensing.
OPTICAL FIBER TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Lu Zhang, Junxiang Zhang, Quan Sheng, Shijie Fu, Yanyan Li, Chaodu Shi, Wei Shi, Jianquan Yao
Summary: In this study, a novel method was proposed and demonstrated to achieve pulsed operation of thulium-doped fiber lasers at 1.7 μm. By embedding the thulium-doped fiber laser cavity within the cavity of an erbium/ytterbium-codoped fiber laser operating at 1.5 μm, the 1.5 μm laser was forced to operate in a passively Q-switched scheme using the thulium-doped fiber as a saturable absorber. The thulium-doped fiber laser at 1.7 μm was then pumped by the Q-switched 1.5 μm laser and gain-switched. The experimental results matched well with the theoretical model, providing insights for further improving the laser performance.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Jinhwa Gene, Dong-Il Yeom, Seung Kwan Kim, Sun Do Lim
Summary: The study introduces a high-energy, low-frequency 2-micron femtosecond fiber laser designed for laser surgery and vehicle laser detection and ranging applications. The laser, incorporating thulium-doped fiber gains and hybrid mode-locking techniques, achieved the highest pulse energy and lowest pulse rate reported to date, with pulse duration and output optical spectrum characteristics also evaluated for stability over extended periods.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Zhiquan Lin, Yan Feng, Dijun Chen, Weibiao Chen
Summary: Compared with Yb, Nd has potential in 1120 nm fiber lasers, and NDF oscillator and NRF oscillator have been successfully built to study the lasing characteristics at 1120 nm.
IEEE PHOTONICS JOURNAL
(2022)
Article
Optics
Wei Huang, Zhiyue Zhou, Yulong Cui, Hao Li, Wenxi Pei, Meng Wang, Zefeng Wang, Jinbao Chen
Summary: We present the characteristics of a continuous wave high-power mid-infrared light source based on acetylene-filled anti-resonant hollow-core fiber. A maximum power of 4.5W at 3.1μm is achieved at the optimal gas pressure of 3mbar, which is the highest output power reported for mid-IR HCF lasers to date. This work demonstrates the great potential of fiber gas lasers for high-power output in the mid-IR.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Alexander Kharakhordin, Andrey Rybaltovsky, Sergei Popov, Dmitry Ryakhovskiy, Fedor Afanasiev, Sergey Alyshev, Aleksandr Khegai, Mikhail Melkumov, Elena Firstova, Yuri Chamorovsky, Andrey Umnikov, Denis Lipatov, Sergei Firstov
Summary: A narrow-linewidth bismuth-doped fiber laser (BDFL) with random cavity and operational wavelength at 1.67 μm was demonstrated. The laser cavity was formed by an array of weakly reflecting fiber Bragg gratings inscribed in the active fiber core directly during the fiber drawing process. The laser behavior was studied in various configurations, and it was found that the laser wavelength can vary within the spectral range of 1.669-1.674 μm depending on the length and ambient temperature of the active fiber.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Jiancheng Deng, Yanxin Li, Ming Shen, Xuewen Shu
Summary: This paper proposes and demonstrates a novel single-frequency erbium-doped random distributed Bragg reflector fiber laser, constructed by a random fiber grating and a high-reflection fiber Bragg grating. The use of femtosecond laser point-by-point inscription technique for the random fiber grating enables easy and low-cost fabrication of long gratings. Experimental results show that the laser achieves stable single-peak emission and operates at a single frequency.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Leonid V. V. Kotov, Valery Temyanko, Mikhail M. M. Bubnov, Denis S. S. Lipatov, Alexey S. S. Lobanov, Alexey Abramov, Svetlana S. S. Aleshkina, Alexey N. N. Guryanov, Mikhail E. E. Likhachev
Summary: In this study, high-energy single frequency transform-limited Er-doped amplifiers were pumped by a specially developed Yb-doped fiber laser at 980 nm and a Raman laser at 1480 nm. It was found that pumping at 1480 nm allows achieving slightly higher maximum pulse energy for long pulses in the absence of nonlinear effects. On the other hand, amplifiers with a pump at 980 nm have a higher threshold of stimulated Brillouin scattering (SBS), enabling higher peak power of shorter pulses. Lasers with more than 730 mu J pulse energy and with higher than 3.5 kW peak power were demonstrated.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Chemistry, Analytical
Antreas Theodosiou, Jan Aubrecht, Ivan Kasik, Daniel Dousek, Matej Komanec, Kyriacos Kalli
Summary: A monolithic fiber laser suitable for CO2 gas sensing applications operating in the short wavelength infrared was proposed, with a laser design based on direct inscription of a monolithic Fabry-Perot cavity in a thulium-doped optical fiber using a femtosecond laser. The performance of the laser cavities was evaluated in terms of power output, slope efficiency, stability, and effective resonator length, showing an improvement exceeding 12% in slope efficiency compared to a reference fiber spliced to FBGs inscribed in passive fiber.
Article
Chemistry, Multidisciplinary
Gaia Ciampalini, Filippo Fabbri, Guido Menichetti, Luca Buoni, Simona Pace, Vaidotas Miseikis, Alessandro Pitanti, Dario Pisignano, Camilla Coletti, Alessandro Tredicucci, Stefano Roddaro
Summary: The conducting properties of graphene-MoS2 heterojunction were investigated, revealing a suppression of transport on the n-side of the transconductance curve due to trapping by sulfur vacancies, which counterintuitively depends on the field effect.
Article
Polymer Science
Michele Monteferrante, Adriano Tiribocchi, Sauro Succi, Dario Pisignano, Marco Lauricella
Summary: This study investigates the free radical polymerization of photocurable polymers using reactive classical molecular dynamics combined with a dynamical approach of the nonequilibrium molecular dynamics (D-NEMD) method. The results provide insights into the physical and topological properties of the polymer and predict its mechanical behavior. This approach offers a novel tool to describe photopolymerization processes and optimize additive manufacturing methods.
Article
Materials Science, Multidisciplinary
Qiuguo Li, Hao Rao, Xinzhou Ma, Haijuan Mei, Zhengting Zhao, Weiping Gong, Andrea Camposeo, Dario Pisignano, Xianguang Yang
Summary: Cu2Te microdisks were successfully prepared using GaTe as Te source, exhibiting a new red emission band in the photoluminescence spectrum and functioning as an efficient optical microcavity for red lasing. These microdisks also serve as ideal substrates for surface enhanced Raman scattering, with high enhancement factor and detection limit to nanomolar level.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Giovanni Morello, Maria Moffa, Martina Montinaro, Annachiara Albanese, Karolis Kazlauskas, Saulius Jursenas, Ausra Tomkeviciene, Juozas Grazulevicius, Andrea Camposeo, Dario Pisignano
Summary: The optical gain of electrospun polystyrene fibers doped with a multi-fragment molecular dye has been studied. Aligned fibers show enhanced performance and the gain spectrum can be tuned by adjusting the dye concentration. On the other hand, randomly oriented fibers exhibit random lasing with a manifold of spectral line narrowing. Increasing the dye content reduces the lasing threshold and allows tuning of the laser emission wavelength. These findings highlight the potential of these fibers for variable-gain, broadband lasing in optical sensing and tunable microlaser devices.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Francesca D'Elia, Francesco Pisani, Alessandro Tredicucci, Dario Pisignano, Andrea Camposeo
Summary: The article introduces 3D-printed and stretchable magic windows that generate light patterns through refraction and can change shape and light texture through controlled strain. It demonstrates cryptographic magic windows with exemplary light patterns and shows how micro-QR-codes are correctly projected and recognized upon strain gating while remaining cryptic for as-produced devices. The novel, freeform elements with 3D shape and tailored functionalities are relevant for various applications such as illumination design, smart labels, anti-counterfeiting systems, and cryptographic communication.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Nanoscience & Nanotechnology
Israel Greenfeld, Andrea Camposeo, Alberto Portone, Luigi Romano, Maria Allegrini, Francesco Fuso, Dario Pisignano, H. Daniel Wagner
Summary: The molecular orientation in polymer fibers can be enhanced by mixing nanowires, resulting in improved optical properties. Experimental results showed that the molecular orientation was significantly increased near the nanowire boundaries. This method has potential applications in improving the performance of optical devices and sensors.
ACS APPLIED NANO MATERIALS
(2022)
Article
Multidisciplinary Sciences
Dhruv Saxena, Alexis Arnaudon, Oscar Cipolato, Michele Gaio, Alain Quentel, Sophia Yaliraki, Dario Pisignano, Andrea Camposeo, Mauricio Barahona, Riccardo Sapienza
Summary: Recent research has shown that random lasing in complex networks can achieve efficient lasing properties and fast-switching multifunctional light sources by controlling the spatial shape of the pump profile. By solving nonlinear equations within the network graph and selectively lasing the strongest intensity modes, the spectrum of the lasing networks can be effectively programmed. This high sensitivity allows for control of the lasing spectrum through non-uniform pump patterns, leading to the development of optical devices with wide impact for on-chip photonics for communication, sensing, and computation.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Matteo Archimi, Ella Schoolaert, Jana Becelaere, Richard Hoogenboom, Andrea Camposeo, Karen De Clerck, Dario Pisignano
Summary: This study reports on switchable optical gain based on arrays of thermo-responsive poly(2-n-propyl-2-oxazoline) nanofibers. The nanofibers exhibit light amplification and high humidity absorption capability. Waveguiding analysis reveals that the switching mechanism is caused by moisture sorption swelling-induced morphological changes. These responsive light-emitting nanofibers have potential applications in dynamically-controlled lasers, environmentally-switchable optoelectronics, and smart sensors.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Luana Persano, Sujoy Kumar Ghosh, Dario Pisignano
Summary: The realization of intelligent, self-powered components and devices exploiting the piezoelectric effect at large scale would greatly improve resource utilization efficiency, but a profound redesign of materials and architectures is required. Polymers, especially PVDF and its copolymers, have been widely used in this field due to their strong piezoelectric response and flexibility. Electrospinning enables the fabrication of piezoelectric polymer nanofibers with desired properties and is suitable for large-scale production.
ACCOUNTS OF MATERIALS RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Paolo Tentori, Giovanni Signore, Andrea Camposeo, Annalisa Carretta, Gianmarco Ferri, Pasqualantonio Pingue, Stefano Luin, Daniela Pozzi, Enrico Gratton, Fabio Beltram, Giulio Caracciolo, Francesco Cardarelli
Summary: The supramolecular organization of Doxorubicin within the standard liposomal formulation was investigated using phasor approach to fluorescence lifetime imaging. The study revealed the existence and molar fractions of three fluorescent species: crystallized, free, and membrane-bound Doxorubicin within the formulation. This research is important for understanding the distribution of drugs in vivo.