Article
Optics
Xiaofan Zhao, Xin Tian, Meng Wang, Hongye Li, Binyu Rao, Zefeng Wang
Summary: A simple tandem inscription method for achieving wideband CTFBGs (WB-CTFBGs) is proposed and experimentally validated for the first time. The influence of key factors on the transmission spectrum is studied in detail by simulation. The validity of the proposed inscription technique has been demonstrated by comparing the Raman suppression effect in a high-power fiber laser system.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Optics
A. Halstuch, A. A. Ishaaya
Summary: Chirped fiber Bragg gratings (CFBGs) and arrays of fiber Bragg gratings (FBGs) were fabricated using femtosecond pulses and a single uniform phase-mask (PM). The fabricated gratings demonstrated tunability in wavelength and achieved non-overlapping inscription on fresh fiber sections. The resulting gratings exhibited spectral shifts and good performance, as measured through transmission and reflection spectra.
OPTICS AND LASERS IN ENGINEERING
(2023)
Article
Optics
Xiao Lei, Fang Ren, Jinyu Zhang, Jingjing Niu, Yanfei Zhang, Yingjuan Ci, Xiaohui Wang, Jianping Wang
Summary: This paper presents a unique design of weakly coupled few-mode photonic crystal fiber (FM-PCF) that supports six vector modes with ultra-flattened chromatic dispersion. The impact of fiber parameters on various performance metrics is investigated using the finite element method. The designed FM-PCF achieves ultra-flattened chromatic dispersion and large effective refractive index difference by introducing an extra small elliptical defected hole in the fiber core. The simulated results show that the designed FM-PCF has an ultra-flattened average dispersion and meets the requirements for large-capacity MDM communication systems.
OPTICAL ENGINEERING
(2022)
Article
Engineering, Electrical & Electronic
Xiao Lei, Fang Ren, Yanfei Zhang, Yingjuan Ci, Xiaohui Wang, Jianping Wang
Summary: This paper proposes a weakly-coupled ultra-flattened chromatic dispersion few-mode photonic crystal fiber, which supports multiple modes over a large range of wavelengths and has ultra-flattened dispersion and large minimum effective refractive index difference. It has potential applications in large-capacity MDM communication systems.
IEEE PHOTONICS JOURNAL
(2022)
Article
Optics
Saket Kaushal, Anthony Roberge, Raman Kashyap, Jose Azana
Summary: Current technologies for on-chip optical group-velocity dispersion (GVD) suffer from long device lengths and high processing latencies. This study presents a novel design strategy that uses discretized and bounded spectral phase filtering to emulate continuous spectral phase variation, resulting in significantly reduced device lengths, on-chip integration, and ultra-low latencies. Experimental results demonstrate compensation of GVD using a 4.1-mm WBG-based on-chip phase filter in a silicon-on-insulator (SOI) platform, which is at least 5 times shorter and achieves processing latency of approximately 100 ps compared to an equivalent linearly chirped waveguide Bragg grating (LCWBG).
Article
Engineering, Electrical & Electronic
Kuikui Guo, Jun He, He Li, Baijie Xu, Shengzhen Lu, Shen Liu, Xizhen Xu, Gaixia Xu, Yiping Wang
Summary: This study introduces a method for fabricating ultra-short Type II FBGs using femtosecond laser technology, which can be used for high temperature sensing and precise temperature field distribution measurements with high spatial resolution, showing promising applications in a large-scale fiber sensor network.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Changming Xia, Zhipeng Deng, Aoyan Zhang, Peng Cai, Zhifeng Mo, Jiantao Liu, Guiyao Zhou, Zhiyun Hou, Qingmao Zhang, Liang Guo
Summary: A novel hollow-core antiresonant fiber with a Bragg structure is proposed, which exhibits advantageous optical properties and potential applications in long-distance communications, data transmission, and laser power delivery.
IEEE PHOTONICS JOURNAL
(2022)
Article
Optics
Shisheng Dong, Bing Han, Han Wu, Kangye Deng, Yang Liu, Yunjiang Rao
Summary: This article introduces the Raman fiber laser (RFL) based on distributed Raman gain along optical fiber, which is an ideal platform for realizing ultra-long-cavity laser. By adopting higher-order pumping and ultra-low-loss fiber (ULLF), the laser cavity length of RFL with resolvable mode structure can be significantly increased. A 364 km-long bi-directional pumped 6th-order ultra-long Raman fiber laser (URFL) based on ULLF is demonstrated, extending the prior 270 km record by 35%.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Lixia Li, Wanlu Li, Xueyang Zong, Yang Zheng, Lin Cui, Yufang Liu
Summary: In this work, a fiber optic sensor based on dielectric nanostructure is proposed and demonstrated for low-cost, microsample testing and compact medical diagnostics. The sensing performance of the sensor, including bulk and surface sensitivities, is systematically investigated, and it is found that the FO sensor based on dielectric nanodisk exhibits a narrow resonance and a linear response to adsorbate layer thickness changes. The work opens a new opportunity for future bio-compatible, robust, and low-loss medical diagnostic devices.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Chemistry, Analytical
Koken Fukushima, Manuel Guterres Soares, Atsushi Wada, Satoshi Tanaka, Fumihiko Ito
Summary: A novel tunable Erbium-doped fiber ring laser with a cascaded-chirped long-period fiber grating as a wavelength selection filter is proposed, in which a variable optical attenuator is used to change the oscillation wavelength region for widening the tuning wavelength range. Demonstrative experiments show successful oscillation over a wavelength range of 12.85 nm and a practical technique for temperature measurement by combining with the VOA control is discussed.
Article
Engineering, Electrical & Electronic
Xiao Lei, Fang Ren, Jinyu Zhang, Jingjing Niu, Yanfei Zhang, Yingjuan Ci, Xiaohui Wang, Jianping Wang
Summary: This paper introduces a novel design of photonic crystal fiber supporting 6 vector modes with ultra-flattened chromatic dispersion. The fiber parameters were investigated to achieve optimized performance, resulting in elliptical defect holes and elliptical holes design. The proposed fiber structure shows promising results with low confinement loss and excellent bending resistance, making it suitable for high-capacity communication systems.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Physics, Multidisciplinary
Naresh Saha, Barnana Roy, Avinash Khare
Summary: Exact chirped elliptic wave solutions are obtained in the presence of non-Kerr nonlinearity. It is shown that a particular combination of the self-steepening and the self-frequency shift parameters can cause chirp reversal. Different combinations of non-Kerr terms lead to chirping but no chirp reversal. The effect of the nonparaxial parameter on physical quantities such as intensity, speed, and pulse width is also studied, and the speed of the solitary wave can be tuned by altering the nonparaxial parameter.
Article
Engineering, Electrical & Electronic
Saket Kaushal, Jose Azana
Summary: This paper provides a detailed analysis of using ultra-compact on-chip discrete spectral phase filters based on waveguide Bragg gratings for managing group-velocity dispersion in broadband waveforms. The study demonstrates the potential for achieving target GVD profiles on high-rate periodic pulsed waveforms and highlights the application possibilities on non-periodic signals.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Optics
Zheyuan Zhang, Takuma Shirahata, Ruiyan Chen, Shinji Yamashita, Sze Yun Set
Summary: This article proposes a new disambiguation method using a laser with chirped amplitude modulation to solve the ranging ambiguity problem in LiDAR techniques. The method achieves an infinitely expanded unambiguous range by sweeping the modulation frequency, leading to high precision in range detection.
Article
Engineering, Electrical & Electronic
Yunqing Guan, Ting Zhang, Xiaopeng Dong, Tong Sun, Kenneth Thomas Victor Grattan
Summary: This article presents a compact fiber-optic sensor based on a fiber Bragg grating (FBG), partially bonded with thick polyimide (PI) films, for the simultaneous measurement of humidity and temperature. The proposed sensing structure with PI films enhances the sensor response to both humidity and temperature significantly.
IEEE SENSORS JOURNAL
(2023)
Article
Optics
V Balaswamy, Santosh Aparanji, S. Arun, Siddharth Ramachandran, V. R. Supradeepa
Article
Physics, Multidisciplinary
A. Antikainen, L. Rishoj, B. Tai, S. Ramachandran, G. P. Agrawal
PHYSICAL REVIEW LETTERS
(2019)
Article
Optics
Jeff Demas, Lars Rishoj, Xiao Liu, Gautam Prabhakar, Siddharth Ramachandran
PHOTONICS RESEARCH
(2019)
Article
Optics
Lars Rishoj, Fengyuan Deng, Boyin Tai, Ji-Xin Cheng, Siddharth Ramachandran
Article
Optics
X. Liu, E. N. Christensen, K. Rottwitt, S. Ramachandran
Article
Multidisciplinary Sciences
Aaron P. Greenberg, Gautam Prabhakar, Siddharth Ramachandran
NATURE COMMUNICATIONS
(2020)
Review
Nanoscience & Nanotechnology
Zelin Ma, Siddharth Ramachandran
Summary: Multimode fibers have attracted renewed attention due to the spatial diversity they offer, with circularly polarized orbital angular momentum modes being identified as the most stable eigenbasis for light propagation in suitably designed fibers. By manipulating light's path memory effects, a controllable means of tailoring light's phase is demonstrated, which has implications for using higher-order modes in optical fiber applications.
Article
Biochemical Research Methods
Jeffrey Demas, Jason Manley, Frank Tejera, Kevin Barber, Hyewon Kim, Francisca Martinez Traub, Brandon Chen, Alipasha Vaziri
Summary: Two-photon microscopy has enabled high-resolution imaging of neuroactivity within scattering brain tissue, but there are still tradeoffs between speed and spatiotemporal sampling. Light beads microscopy (LBM) introduces a scalable and spatiotemporally optimal acquisition approach for recording neuroactivity at different scales, offering opportunities for discovering neurocomputations in the mammalian brain.
Proceedings Paper
Engineering, Electrical & Electronic
Aaron P. Greenberg, Gautam Prabhakar, Siddharth Ramachandran
2020 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Aku Antikainen, Havva Begum Kabagoz, Siddharth Ramachandran
2020 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Lars Rishoj, Ivan Coto Hernandez, Nate Jowett, Siddharth Ramachandran
2020 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Zelin Ma, Poul Kristensen, Siddharth Ramachandran
2020 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Robert Lindberg, Xiao Liu, Siddharth Ramachandran, Valdas Pasiskevicius
2020 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Xiao Liu, Aku Antikainen, Zelin Ma, Poul Kristensen, Siddharth Ramachandran
2020 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Havva Begum Kabagoz, Siyuan Zhang, Lars Rishoj, Aku Antikainen, Siddharth Ramachandran
2020 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2020)
