Article
Optics
Wenwen Cui, Zheng Yi, Xinyu Ma, Yong Geng, Heng Zhou, Kun Qiu
Summary: In this study, a new microcavity structure was used to improve the output power of soliton combs, and the energy conversion efficiency was significantly higher than previous research results. This has important practical applications in fields such as optical communication and optical frequency combs.
CHINESE OPTICS LETTERS
(2023)
Article
Optics
Guoping Lin, Tang Sun
Summary: This study demonstrates the fabrication of high-Q crystalline optical microresonators from cubic yttria-stabilized zirconia (YSZ) for the first time. The research shows interesting optical phenomena and opens up new possibilities for the design and applications of optical devices.
PHOTONICS RESEARCH
(2022)
Article
Optics
Valery E. Lobanov, Nikita M. Kondratiev, Igor A. Bilenko
Summary: The study demonstrates a novel mechanism for generating flat-top solitonic pulses, platicons, in optical microresonators under normal group velocity dispersion via negative thermal effects. Two regimes of platicon generation are identified based on the pump amplitude: smooth and oscillatory. Parameter ranges for platicon excitation are analyzed for different thermal relaxation times, frequency scan rates, and GVD coefficients, showing the possibility of turn-key generation.
Article
Optics
Jianxing Pan, Tianye Huang, Yutian Wang, Zhichao Wu, Jing Zhang, Luming Zhao
Summary: The use of nonlinear Fourier transform to filter out sidebands and achieve perfect solitons in a macroscopic fiber ring resonator is demonstrated in this study, providing an effective method for CS analysis.
Article
Optics
Martin Brunzell, Max Widarsson, Christoffer Krook, Laura Barrett, Andrius Zukauskas, Fredrik Laurell, Valdas Pasiskevicius
Summary: This paper presents an Nd:YVO4 laser operating at 1064 nm, which generates a stable mode-locked train of 10 ps-long dark pulses with a repetition rate of 211 MHz. The mode-locking is achieved through a periodic loss modulation produced by intra-cavity sum-frequency mixing with a synchronous bright-pulse train from a mode-locked femtosecond Yb:KYW laser at 1040 nm. The modulation depth of the dark pulses was measured to be 9050, confirmed by cross-correlation measurements. The ultrafast loss modulation injects power into the Nd:YVO4 laser cavity modes beyond the laser gain bandwidth, leading to the generation of periodic ultra-fast transients at frequencies above 1.5 THz when interacting with the lasing modes at the proper laser cavity length.
Article
Engineering, Electrical & Electronic
Shiqi He, Nuo Chen, Hanghang Li, Xiaolong Fan, Wenchan Dong, Jianji Dong, Heng Zhou, Xinliang Zhang, Jing Xu
Summary: Optical parametric amplifiers (OPAs) based on four-wave mixing processes have great potential in various fields. Recently, integrated OPAs based on highly nonlinear micro-ring resonators (MRRs) have achieved significant progress, thanks to enhanced optical-matter interactions. This study derives analytical formulas for the parametric gain and conversion efficiency (CE) of high-Q MRRs with high-pump excitation, showing the interplay between parametric gain and field enhancement. The theory agrees well with numerical and experimental results.
IEEE PHOTONICS JOURNAL
(2023)
Article
Multidisciplinary Sciences
Sanjeet Kumar Singh, Om Prakash, Shantanu Bhattacharya
Summary: The proposed work introduces a new type of acoustic metamaterial, utilizing fractal structures and micro-perforated panels to achieve superior sound absorption in a wide frequency range. The peaks of sound absorption phenomena can be tuned by adjusting geometric parameters. This material design has various applications in functional materials with broad-band absorption behavior.
SCIENTIFIC REPORTS
(2022)
Review
Physics, Multidisciplinary
Mengxi Tan, Xingyuan Xu, Jiayang Wu, Roberto Morandotti, Arnan Mitchell, David J. Moss
Summary: Integrated Kerr micro-combs are a powerful source of multiple wavelength channels for photonic RF and microwave signal processing, offering advantages such as compact device footprint, high versatility, large numbers of wavelengths, and wide Nyquist bands. Research focuses on Hilbert transforms, differentiators, and integrators. The future potential of optical micro-combs for RF photonic applications is discussed in terms of functionality and ability to realize integrated solutions.
ADVANCES IN PHYSICS-X
(2021)
Article
Optics
Milica Banic, Marco Liscidini, J. E. Sipe
Summary: This paper discusses third-order parametric downconversion (TOPDC) and its application in generating quantum correlated photon pairs. By modeling stimulated TOPDC in a microring resonator, the study predicts observable pair generation rates and compares the peculiar features of this approach with other nonlinear interactions.
Article
Multidisciplinary Sciences
Chao Xiang, Joel Guo, Warren Jin, Lue Wu, Jonathan Peters, Weiqiang Xie, Lin Chang, Boqiang Shen, Heming Wang, Qi-Fan Yang, David Kinghorn, Mario Paniccia, Kerry J. Vahala, Paul A. Morton, John E. Bowers
Summary: Achieving high output power and low noise integrated lasers using Si/SiN heterogeneous platform with Hertz-level linewidth has been demonstrated. This paves the way for fully integrating low-noise silicon nitride photonics in volume. The high-performance lasers on SiN with tens of milliwatts output power and sub-kHz fundamental linewidth address issues of mode transition loss, cavity design, and fabrication process, marking a milestone towards fully integrated low-noise silicon nitride photonics platform.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Shuai Yuan, Yunkun Wu, Zhongzhou Dang, Cheng Zeng, Xiaozhuo Qi, Guangcan Guo, Xifeng Ren, Jinsong Xia
Summary: This study demonstrates strongly enhanced second harmonic generation on thin film lithium niobate, achieving a record high conversion efficiency compared to conventional thin film materials, which could inspire the miniaturization and integration in this field.
PHYSICAL REVIEW LETTERS
(2021)
Article
Computer Science, Artificial Intelligence
Muhammad Hassan, Yan Wang, Wei Pang, Di Wang, Daixi Li, You Zhou, Dong Xu
Summary: Shoeprints are important for tracing evidence in forensic scenes, and the generation of high-fidelity shoeprints is crucial in forensic science. A deep learning based GUV-Net model is proposed to address the challenges in shoeprint processing and lack of specific algorithms, achieving efficient optimization of parameters for mapping low quality images to high-fidelity ones while maintaining salient forensic features. The performance of the proposed model is evaluated against state-of-the-art super-resolution network models.
COMPLEX & INTELLIGENT SYSTEMS
(2022)
Article
Optics
Qianchao Wu, Lifang Chen, Zheng Wu, Lingchun Lei, Yong Yao
Summary: In this paper, a flexibly cascaded femtosecond soliton fiber laser based on optical circulators is proposed and demonstrated. The experimental results of a cascaded dual-ring-cavity fiber laser show that the cascaded N-ring-cavity ultrafast fiber laser has advantages such as compact structure, multi-channel output, and independent operation.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Automation & Control Systems
Jonathan Ho, Chitwan Saharia, William Chan, David J. Fleet, Mohammad Norouzi, Tim Salimans
Summary: We demonstrate that cascaded diffusion models can generate high fidelity images on the class-conditional ImageNet generation benchmark. By using a pipeline of multiple diffusion models, the image resolution is gradually increased, and a conditioning augmentation method is proposed to improve sample quality. Experimental results show that cascading pipelines can achieve outstanding performance without the need for auxiliary image classifiers.
JOURNAL OF MACHINE LEARNING RESEARCH
(2022)
Article
Optics
Yun-Ru Fan, Chen Lyu, Chen-Zhi Yuan, Guang-Wei Deng, Zhi-Yuan Zhou, Yong Geng, Hai-Zhi Song, You Wang, Yan-Feng Zhang, Rui-Bo Jin, Heng Zhou, Li-Xing You, Zhen Wang, Guang-Can Guo, Qiang Zhou
Summary: This study demonstrates a multi-wavelength quantum light source using a silicon nitride micro-ring with a free spectral range of 200 GHz. By optimizing the device and using noise-rejecting filters, the source can generate eight-wavelength-paired photon pairs in a wavelength range of 25.6 nm. It also enables the generation of heralded single-photons at a rate of 62 kHz with gh(2)(0)=0.014 & PLUSMN;0.001$g<^>{(2)}_{h}(0)=0.014\pm 0.001$ and energy-time entangled photons with a visibility of 99.39 & PLUSMN;0.45%$99.39\pm 0.45\%$ in the Franson interferometer. These results, achieved at room temperature and telecom wavelength, on a CMOS-compatible platform, represent a significant step towards integrated quantum photonic devices and the realization of large-scale quantum networks.
LASER & PHOTONICS REVIEWS
(2023)
Article
Environmental Sciences
Lijian Han, Xiaoyan Zhang, Weiqi Zhou, Miaogen Shen, Yan Huang, Weifeng Li, Yuguo Qian
Summary: In recent years, rapid urbanization in China has significantly impacted the eco-environment, with studies showing a correlation between urban expansion and population-weighted vegetation and PM2.5 concentration. Different periods of urban expansion have demonstrated varying trends in population-weighted vegetation and PM2.5 concentration.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Nursing
M. D. Shen, Y. W. Li, L. Q. Xu, H. Y. Shi, Y. Y. Ni, H. J. Lin, F. Li
Summary: The study aimed to investigate the effect of active cycle of breathing technique on sputum viscosity and production among patients with chronic obstructive pulmonary disease. The results showed significant improvements in respiratory function and sputum production with the intervention.
INTERNATIONAL JOURNAL OF NURSING STUDIES
(2021)
Article
Optics
Yuntao Xu, Mohan Shen, Juanjuan Lu, Joshua B. Surya, Ayed Al Sayem, Hong X. Tang
Summary: This study demonstrates that the dielectric cladding on thin-film lithium niobate microring resonators has a significant impact on the photorefractive effect, and removing the dielectric cladding layer can effectively alleviate this effect. This research offers a reliable method for controlling the photorefractive effect on thin-film lithium niobate, which will further enhance the performance of integrated classical and quantum photonic devices based on thin-film lithium niobate.
Article
Chemistry, Multidisciplinary
Tae-Yeon Hwang, Junghyun Lee, Seung-Woo Jeon, Yong-Su Kim, Young-Wook Cho, Hyang-Tag Lim, Sung Moon, Sang-Wook Han, Yong-Ho Choa, Hojoong Jung
Summary: In this work, sub-10 nm precision nitrogen vacancy (NV) color centers are successfully generated in diamond using nanoscale aperture arrays (NAAs) and a secondary E-beam hole pattern. Optical and spin measurements are performed on a cluster of NV spins, and the effect of NAAs during ion-implantation process is statistically investigated. The effectiveness of this technique for constructing a scalable system is discussed.
Article
Optics
Zheng Gong, Alexander W. Bruch, Fengyan Yang, Ming Li, Juanjuan Lu, Joshua B. Surya, Chang-Ling Zou, Hong X. Tang
Summary: Photonic platforms with chi((2)) nonlinearity provide new possibilities for Kerr frequency comb development. In this study, Kerr soliton generation and dual-band mode-locked combs are demonstrated in a single AlN microring through phasematched quadratic coupling. By engineering the chi((2)) phase-matching wavelength, a balance between high conversion efficiency and high soliton formation rate can be achieved under the given conditions of pump power and microring quality factors.
Article
Optics
Mengqi Shen, Qi Zou, Xiaoping Jiang, Fu Feng, Michael G. Somekh
Summary: This paper introduces a new optical system that implements a single-shot three-input phase retrieval algorithm, allowing simultaneous acquisition of three different input patterns for improved measurement accuracy and speed, while simplifying hardware operations.
PHOTONICS RESEARCH
(2022)
Article
Quantum Science & Technology
Chang Hoon Park, Min Ki Woo, Byung Kwon Park, Yong-Su Kim, Hyeonjun Baek, Seung-Woo Lee, Hyang-Tag Lim, Seung-Woo Jeon, Hojoong Jung, Sangin Kim, Sang-Wook Han
Summary: Recent research has shown that while QKD networks using conventional protocols have been studied thoroughly, twin-field QKD (TF-QKD) has succeeded in long-distance QKD, but has only been verified for ring networks.
NPJ QUANTUM INFORMATION
(2022)
Article
Engineering, Electrical & Electronic
Xiaoping Jiang, Mengqi Shen, Daniel Pak-Kong Lun, Wen Chen, Michael G. Somekh
Summary: This paper presents a high aspect-ratio open grating Fabry-Perot resonator for aqueous refractive index sensing. The use of transmission line modeling and Smith charts provides a better understanding of the physical sensing mechanism. Experimental results show a significant improvement in performance compared to conventional surface plasmon resonance technology.
IEEE SENSORS JOURNAL
(2022)
Article
Optics
Min Ki Woo, Chang Hoon Park, Byung Kwon Park, Hojoong Jung, Dongyeon Kang, Seung-Woo Jeon, Sangin Kim, Sang-Wook Han
Summary: This study proposes a new method that eliminates the bulky storage line in the plug-and-play quantum key distribution system by realizing an optical pulse train generator based on an optical cavity structure. It improves the secure key rate.
Article
Computer Science, Information Systems
Chang-Hoon Park, Min-Ki Woo, Byung-Kwon Park, Seung-Woo Jeon, Hojoong Jung, Sangin Kim, Sang-Wook Han
Summary: In this study, a bias control method for Mach-Zehnder modulator (MZM) using diagnostic pulses is proposed for efficient application in a quantum key distribution (QKD) system without additional hardware. The method maintains the MZM extinction ratio stably, even in an actual network environment, and achieves successful QKD performances.
Article
Optics
Hyeon Hwang, Hyungjun Heo, Kiyoung Ko, Mohamad Reza Nurrahman, Kiwon Moon, Jung Jin Ju, Sang-Wook Han, Hojoong Jung, Hansuek Lee, Min-Kyo Seo
Summary: This study demonstrates a two-point coupled lithium niobate racetrack micro-resonator that allows for electro-optical modulation between the zero- and critical-coupling conditions with minimal disturbance to the intrinsic properties of the resonant mode.
Article
Optics
Zheng Gong, Mohan Shen, Juanjuan Lu, Joshua B. Surya, Hong X. Tang
Summary: Hybrid Kerr and electro-optic microcombs based on a lithium niobate thin film are demonstrated, enabling direct electronic detection and feedback control of terahertz soliton repetition rates by interleaving high-repetition-rate Kerr soliton comb with low-repetition-rate electro-optic comb on the same waveguide.
Article
Optics
Zhier Qu, Xianwen Liu, Cheng Zhang, Jin Wang, Yongtian Wang, Yijie Pan, JiFeng Qu
Summary: In this paper, a semi-automatic method is developed to fabricate ultra-high Q-factor MgF2 micro-resonators. Trapezoid MgF2 resonators are successfully fabricated with a diameter of 9.5 mm, root mean square surface roughness of 0.26 nm, and a maximum difference of peaks and valleys of 1.5 nm. The Q-factor is characterized to be 9.24 x 10(9) at 1550 nm, and a single soliton optical frequency comb is generated by pumping the microcavity with 150mW optical power.
Article
Optics
Junaid Ur Rehman, Seongjin Hong, Seung-Woo Lee, Yong-Su Kim, Young-Wook Cho, Hojoong Jung, Sung Moon, Hyundong Shin, Sang-Wook Han, Hyang-Tag Lim
Summary: Quantum multiple parameter estimation can achieve enhanced sensitivity beyond the classical limit. Experimental implementations to saturate the quantum Cramer-Rao bound typically require impractical entangled measurements, while the practical sensitivity is given by the Cramer-Rao bound relevant to the measurement probabilities.
