Journals
Advanced Photonics
Photonics Insights
Advanced Photonics Nexus
Photonics Research
Advanced Imaging
View All Journals
Chinese Optics Letters
High Power Laser Science and Engineering
Articles
Optics
Physics
Geography
View All Subjects
Conferences
CIOP
HPLSE
AP
View All Events
News
About CLP
Search by keywords or author
Login
Registration
Login in
Registration
Search
Search
Articles
Journals
News
Advanced Search
Top Searches
laser
the
2D Materials
Transformation optics
Quantum Photonics
Home
About
Early Posting
Current Issue
Issue in Progress
Special Issues
All Issues
Special Events
Journals >
>
Topics >
Nonlinear Optics
Contents
Nonlinear Optics
|
121 Article(s)
Second-harmonic generation in periodic fork-shaped χ
(2)
gratings at oblique incidence
Yan Sheng, Shan Liu, Xiaokang Hu, Xin Chen, Tianxiang Xu, Ruwei Zhao, and Wieslaw Krolikowski
Three-dimensional (3D) nonlinear photonic crystals have received intensive interest as an ideal platform to study nonlinear wave interactions and explore their applications. Periodic fork-shaped gratings are extremely important in this context because they are capable of generating second-harmonic vortex beams from a fundamental Gaussian wave, which has versatile applications in optical trapping and materials engineering. However, previous studies mainly focused on the normal incidence of the fundamental Gaussian beam, resulting in symmetric emissions of the second-harmonic vortices. Here we present an experimental study on second-harmonic vortex generation in periodic fork-shaped gratings at oblique incidence, in comparison with the case of normal incidence. More quasi-phase-matching resonant wavelengths have been observed at oblique incidence, and the second-harmonic emissions become asymmetric against the incident beam. These results agree well with theoretic explanations. The oblique incidence of the fundamental wave is also used for the generation of second-harmonic Bessel beams with uniform azimuthal intensity distributions. Our study is important for a deeper understanding of nonlinear interactions in a 3D periodic medium. It also paves the way toward achieving high-quality structured beams at new frequencies, which is important for manipulation of the orbital angular momentum of light.
Three-dimensional (3D) nonlinear photonic crystals have received intensive interest as an ideal platform to study nonlinear wave interactions and explore their applications. Periodic fork-shaped gratings are extremely important in this context because they are capable of generating second-harmonic vortex beams from a fundamental Gaussian wave, which has versatile applications in optical trapping and materials engineering. However, previous studies mainly focused on the normal incidence of the fundamental Gaussian beam, resulting in symmetric emissions of the second-harmonic vortices. Here we present an experimental study on second-harmonic vortex generation in periodic fork-shaped gratings at oblique incidence, in comparison with the case of normal incidence. More quasi-phase-matching resonant wavelengths have been observed at oblique incidence, and the second-harmonic emissions become asymmetric against the incident beam. These results agree well with theoretic explanations. The oblique incidence of the fundamental wave is also used for the generation of second-harmonic Bessel beams with uniform azimuthal intensity distributions. Our study is important for a deeper understanding of nonlinear interactions in a 3D periodic medium. It also paves the way toward achieving high-quality structured beams at new frequencies, which is important for manipulation of the orbital angular momentum of light.
showLess
Chinese Optics Letters
Publication Date: Apr. 25, 2024
Vol. 22, Issue 4, 041902 (2024)
Get PDF
View fulltext
Integrated Fabry–Perot interferometer based on Er/Yb co-doped fiber for all-optical phase modulation
Fan Wang, Siyu Lin, Yanchen Qu, Xiaopeng Han, and Yundong Zhang
Fast and stable phase control is essential for many applications in optics. Here, we propose an all-fiber all-optical phase modulation scheme based on a Fabry–Perot interferometer (FPI) and an Er/Yb co-doped fiber (EYDF). By using the EYDF as an F-P cavity via rational design, a phase shift with a modulation sensitivity of 0.0312π/mW is introduced to the modulator. The phase shifts in the EYDF consist of a thermal phase shift and a nonlinear phase shift with a ratio of 19:1, and the corresponding temporal responses of the modulation are 204 ms and 2.5 ms, respectively. In addition, the compact FPI is encapsulated to provide excellent stability for the modulator.
Fast and stable phase control is essential for many applications in optics. Here, we propose an all-fiber all-optical phase modulation scheme based on a Fabry–Perot interferometer (FPI) and an Er/Yb co-doped fiber (EYDF). By using the EYDF as an F-P cavity via rational design, a phase shift with a modulation sensitivity of 0.0312π/mW is introduced to the modulator. The phase shifts in the EYDF consist of a thermal phase shift and a nonlinear phase shift with a ratio of 19:1, and the corresponding temporal responses of the modulation are 204 ms and 2.5 ms, respectively. In addition, the compact FPI is encapsulated to provide excellent stability for the modulator.
showLess
Chinese Optics Letters
Publication Date: Apr. 17, 2024
Vol. 22, Issue 4, 041901 (2024)
Get PDF
View fulltext
Broadband second-harmonic generation in thin-film lithium niobate microdisk via cyclic quasi-phase matching
Jiefu Zhu, Tingting Ding, Xuerui Sun, Fengchao Ni, Hao Li, Shijie Liu, Yuanlin Zheng, and Xianfeng Chen
Whispering-gallery-mode (WGM) microresonators can greatly enhance light–matter interaction, making them indispensable units for frequency conversion in nonlinear optics. Efficient nonlinear wave mixing in microresonators requires stringent simultaneous optical resonance and phase-matching conditions. Thus, it is challenging to achieve efficient frequency conversion over a broad bandwidth. Here, we demonstrate broadband second-harmonic generation (SHG) in the x-cut thin-film lithium niobate (TFLN) microdisk with a quality factor above 107 by applying the cyclic quasi-phase-matching (CQPM) mechanism, which is intrinsically applicable for broadband operation. Broadband SHG of continuous-wave laser with a maximum normalized conversion efficiency of ∼15%/mW is achieved with a bandwidth spanning over 100 nm in the telecommunication band. Furthermore, broadband SHG of femtosecond lasers, supercontinuum lasers, and amplified spontaneous emission in the telecommunication band is also experimentally observed. The work is beneficial for integrated nonlinear photonics devices like frequency converters and optical frequency comb generator based on second-order nonlinearity on the TFLN platform.
Whispering-gallery-mode (WGM) microresonators can greatly enhance light–matter interaction, making them indispensable units for frequency conversion in nonlinear optics. Efficient nonlinear wave mixing in microresonators requires stringent simultaneous optical resonance and phase-matching conditions. Thus, it is challenging to achieve efficient frequency conversion over a broad bandwidth. Here, we demonstrate broadband second-harmonic generation (SHG) in the x-cut thin-film lithium niobate (TFLN) microdisk with a quality factor above 107 by applying the cyclic quasi-phase-matching (CQPM) mechanism, which is intrinsically applicable for broadband operation. Broadband SHG of continuous-wave laser with a maximum normalized conversion efficiency of ∼15%/mW is achieved with a bandwidth spanning over 100 nm in the telecommunication band. Furthermore, broadband SHG of femtosecond lasers, supercontinuum lasers, and amplified spontaneous emission in the telecommunication band is also experimentally observed. The work is beneficial for integrated nonlinear photonics devices like frequency converters and optical frequency comb generator based on second-order nonlinearity on the TFLN platform.
showLess
Chinese Optics Letters
Publication Date: Mar. 22, 2024
Vol. 22, Issue 3, 031903 (2024)
Get PDF
View fulltext
Nonlinear photonic quasi-periodic spiral
|
Editors' Pick
Jing Zeng, Sen Wang, Ruwei Zhao, Yongxing Liu, Tiefeng Xu, Yan Sheng, and Tianxiang Xu
The design of nonlinear photonic Vogel’s spiral based on quasi-crystal theory was demonstrated. Two main parameters of Vogel’s spiral were arranged to obtain multi-reciprocal circles. Typical structure was fabricated by the near-infrared femtosecond laser poling technique, forming a nonlinear photonic structure, and multiple ring-like nonlinear Raman–Nath second-harmonic generation processes were realized and analyzed in detail. The structure for the cascaded third-harmonic generation process was predicted. The results could help deepen the understanding of Vogel’s spiral and quasi-crystal and pave the way for the combination of quasi-crystal theory with more aperiodic structures.
The design of nonlinear photonic Vogel’s spiral based on quasi-crystal theory was demonstrated. Two main parameters of Vogel’s spiral were arranged to obtain multi-reciprocal circles. Typical structure was fabricated by the near-infrared femtosecond laser poling technique, forming a nonlinear photonic structure, and multiple ring-like nonlinear Raman–Nath second-harmonic generation processes were realized and analyzed in detail. The structure for the cascaded third-harmonic generation process was predicted. The results could help deepen the understanding of Vogel’s spiral and quasi-crystal and pave the way for the combination of quasi-crystal theory with more aperiodic structures.
showLess
Chinese Optics Letters
Publication Date: Mar. 21, 2024
Vol. 22, Issue 3, 031902 (2024)
Get PDF
View fulltext
Talbot effect in anti-PT symmetric synthetic photonic lattices
Zhaofeng Liu, Siwei Tang, Zengrun Wen, Yuanmei Gao, Yangjian Cai, and Liren Zheng
We investigated the Talbot effect in an anti-parity-time (PT) symmetric synthetic photonic lattice composed of two coupled fiber loops. We calculated the band structures and found that with an increase in the gain-loss parameter, the band transitions from a real spectrum to a complex spectrum. We study the influence of phase in the Hermitian operator on the Talbot effect, and the Talbot effect disappears when the period of the input field is N > 8. Further study shows that the variation of Talbot distance can also be modulated by non-Hermitian coefficients of gain and loss. This work may find significant applications in pulse repetition-rate multiplication, temporal invisibility, and tunable intensity amplifiers.
We investigated the Talbot effect in an anti-parity-time (PT) symmetric synthetic photonic lattice composed of two coupled fiber loops. We calculated the band structures and found that with an increase in the gain-loss parameter, the band transitions from a real spectrum to a complex spectrum. We study the influence of phase in the Hermitian operator on the Talbot effect, and the Talbot effect disappears when the period of the input field is N > 8. Further study shows that the variation of Talbot distance can also be modulated by non-Hermitian coefficients of gain and loss. This work may find significant applications in pulse repetition-rate multiplication, temporal invisibility, and tunable intensity amplifiers.
showLess
Chinese Optics Letters
Publication Date: Mar. 21, 2024
Vol. 22, Issue 3, 031901 (2024)
Get PDF
View fulltext
Controllable transitions among phase-matching conditions in a single nonlinear crystal
Ziqi Zeng, Shixin You, Zixiang Yang, Chenzhi Yuan, Chenglong You, and Ruibo Jin
Entangled photon pairs are crucial resources for quantum information processing protocols. Via the process of spontaneous parametric downconversion (SPDC), we can generate these photon pairs using bulk nonlinear crystals. Traditionally, the crystal is designed to satisfy a specific type of phase-matching condition. Here, we report controllable transitions among different types of phase matching in a single periodically poled potassium titanyl phosphate crystal. By carefully selecting pump conditions, we can satisfy different phase-matching conditions. This allows us to observe first-order Type-II, fifth-order Type-I, third-order Type-0, and fifth-order Type-II SPDCs. The temperature-dependent spectra of our source were also analyzed in detail. Finally, we discussed the possibility of observing more than nine SPDCs in this crystal. Our work not only deepens the understanding of the physics behind phase-matching conditions, but also offers the potential for a highly versatile entangled biphoton source for quantum information research.
Entangled photon pairs are crucial resources for quantum information processing protocols. Via the process of spontaneous parametric downconversion (SPDC), we can generate these photon pairs using bulk nonlinear crystals. Traditionally, the crystal is designed to satisfy a specific type of phase-matching condition. Here, we report controllable transitions among different types of phase matching in a single periodically poled potassium titanyl phosphate crystal. By carefully selecting pump conditions, we can satisfy different phase-matching conditions. This allows us to observe first-order Type-II, fifth-order Type-I, third-order Type-0, and fifth-order Type-II SPDCs. The temperature-dependent spectra of our source were also analyzed in detail. Finally, we discussed the possibility of observing more than nine SPDCs in this crystal. Our work not only deepens the understanding of the physics behind phase-matching conditions, but also offers the potential for a highly versatile entangled biphoton source for quantum information research.
showLess
Chinese Optics Letters
Publication Date: Feb. 20, 2024
Vol. 22, Issue 2, 021901 (2024)
Get PDF
View fulltext
Ultrabroadband second-harmonic generation via spatiotemporal-coupled phase matching
Yudong Tao, Wentao Zhu, Yanfang Zhang, Jingui Ma, Jing Wang, Peng Yuan, Hao Zhang, Heyuan Zhu, and Liejia Qian
We propose a spatially chirped quasi-phase-matching (QPM) scheme that enables ultrabroadband second-harmonic-generation (SHG) by using a fan-out QPM grating to frequency-convert a spatially chirped fundamental wave. A “zero-dispersion” 4f system maps the spectral contents of ultrabroadband fundamental onto different spatial coordinates in the Fourier plane, where the fundamental is quasi-monochromatic locally in picosecond duration, fundamentally canceling high-order phase mismatch. A fan-out QPM grating characterized by a linear variation of the poling period along the transverse direction exactly supports the QPM of the spatially chirped beam. We theoretically demonstrate the SHG of an 810-nm, 12.1-fs pulse into a 405-nm, 10.2-fs pulse with a conversion efficiency of 77%.
We propose a spatially chirped quasi-phase-matching (QPM) scheme that enables ultrabroadband second-harmonic-generation (SHG) by using a fan-out QPM grating to frequency-convert a spatially chirped fundamental wave. A “zero-dispersion” 4f system maps the spectral contents of ultrabroadband fundamental onto different spatial coordinates in the Fourier plane, where the fundamental is quasi-monochromatic locally in picosecond duration, fundamentally canceling high-order phase mismatch. A fan-out QPM grating characterized by a linear variation of the poling period along the transverse direction exactly supports the QPM of the spatially chirped beam. We theoretically demonstrate the SHG of an 810-nm, 12.1-fs pulse into a 405-nm, 10.2-fs pulse with a conversion efficiency of 77%.
showLess
Chinese Optics Letters
Publication Date: Jan. 08, 2024
Vol. 22, Issue 1, 011901 (2024)
Get PDF
View fulltext
Thickness dependency of nonlinear optical properties in ITO/Sn composite films
Boyang Nan, Ruijin Hong, Chunxian Tao, Qi Wang, Hui Lin, Zhaoxia Han, and Dawei Zhang
In this study, a batch of indium tin oxide (ITO)/Sn composites with different ratios was obtained based on the principle of thermal evaporation by an electron beam. The crystalline structure, surface shape, and optical characterization of the films were researched using an X-ray diffractometer, an atomic force microscope, a UV-Vis-NIR dual-beam spectrophotometer, and an open-hole Z-scan system. By varying the relative thickness ratio of the ITO/Sn bilayer film, tunable nonlinear optical properties were achieved. The nonlinear saturation absorption coefficient β maximum of the ITO/Sn composites is -10.5×10-7 cm/W, approximately 21 and 1.72 times more enhanced compared to monolayer ITO and Sn, respectively. Moreover, the improvement of the sample nonlinear performance was verified using finite-difference in temporal domain simulations.
In this study, a batch of indium tin oxide (ITO)/Sn composites with different ratios was obtained based on the principle of thermal evaporation by an electron beam. The crystalline structure, surface shape, and optical characterization of the films were researched using an X-ray diffractometer, an atomic force microscope, a UV-Vis-NIR dual-beam spectrophotometer, and an open-hole Z-scan system. By varying the relative thickness ratio of the ITO/Sn bilayer film, tunable nonlinear optical properties were achieved. The nonlinear saturation absorption coefficient β maximum of the ITO/Sn composites is -10.5×10-7 cm/W, approximately 21 and 1.72 times more enhanced compared to monolayer ITO and Sn, respectively. Moreover, the improvement of the sample nonlinear performance was verified using finite-difference in temporal domain simulations.
showLess
Chinese Optics Letters
Publication Date: Aug. 08, 2023
Vol. 21, Issue 8, 081902 (2023)
Get PDF
View fulltext
Nonlinear harmonic generation of terahertz waves in a topological valley polaritonic microcavity
Yao Lu, Hao Xiong, Yibo Huang, Qiang Wu, Jiwei Qi, Chongpei Pan, and Jingjun Xu
Compact terahertz (THz) devices, especially for nonlinear THz components, have received more and more attention due to their potential applications in THz nonlinearity-based sensing, communications, and computing devices. However, effective means to enhance, control, and confine the nonlinear harmonics of THz waves remain a great challenge for micro-scale THz nonlinear devices. In this work, we have established a technique for nonlinear harmonic generation of THz waves based on phonon polariton-enhanced giant THz nonlinearity in a 2D-topologically protected valley photonic microcavity. Effective THz harmonic generation has been observed in both noncentrosymmetric and centrosymmetric nonlinear materials. These results can provide a valuable reference for the generation and control of THz high-harmonics, thus developing new nonlinear devices in the THz regime.
Compact terahertz (THz) devices, especially for nonlinear THz components, have received more and more attention due to their potential applications in THz nonlinearity-based sensing, communications, and computing devices. However, effective means to enhance, control, and confine the nonlinear harmonics of THz waves remain a great challenge for micro-scale THz nonlinear devices. In this work, we have established a technique for nonlinear harmonic generation of THz waves based on phonon polariton-enhanced giant THz nonlinearity in a 2D-topologically protected valley photonic microcavity. Effective THz harmonic generation has been observed in both noncentrosymmetric and centrosymmetric nonlinear materials. These results can provide a valuable reference for the generation and control of THz high-harmonics, thus developing new nonlinear devices in the THz regime.
showLess
Chinese Optics Letters
Publication Date: Aug. 07, 2023
Vol. 21, Issue 8, 081901 (2023)
Get PDF
View fulltext
Self-focusing of partially coherent beams based on complex screen and split-step Fourier transform methods
Fanglun Yang, Guowen Zhang, Xiaoqi Zhang, Yanli Zhang, Ruifeng Wang, and Jianqiang Zhu
The self-focusing phenomenon of partially coherent beams (PCBs) was simulated using the complex screen method combined with the split-step Fourier method to solve the nonlinear Schrödinger equation. Considering the propagation of Gaussian Schell-model beams in a nonlinear medium as an example, the suppression effects of intensity, propagation distance, and spatial coherence on small-scale self-focusing were demonstrated. Simulations of overall and small-scale self-focusing using this method were compared with the existing literature to demonstrate the validity of the method. This method can numerically analyze the degree of self-focusing in PCBs and advance the study of their nonlinearity.
The self-focusing phenomenon of partially coherent beams (PCBs) was simulated using the complex screen method combined with the split-step Fourier method to solve the nonlinear Schrödinger equation. Considering the propagation of Gaussian Schell-model beams in a nonlinear medium as an example, the suppression effects of intensity, propagation distance, and spatial coherence on small-scale self-focusing were demonstrated. Simulations of overall and small-scale self-focusing using this method were compared with the existing literature to demonstrate the validity of the method. This method can numerically analyze the degree of self-focusing in PCBs and advance the study of their nonlinearity.
showLess
Chinese Optics Letters
Publication Date: Jul. 10, 2023
Vol. 21, Issue 7, 071901 (2023)
Get PDF
View fulltext
Topics
3d holographic display
3d imaging and display
Applications
Atmospheric and oceanic optics
Atmospheric, Oceanic, Space, and Environmental Optics
Atomic and Molecular Optics
Atomic and Molecular Physics
Auto-stereography and virtual reality
Biomedical Optics
Biophotonics
Coatings for solar cell
Coherence and statistical optics
COHERENCE OPTICS AND STATISTICAL OPTICS
Computer generated hologram
Computer-generated holography
Deposition and process control
Design and analysis
Detectors
Diffraction and Gratings
Diffraction, Gratings, and Holography
Digital Holography
Duv/euv coatings
Editorial
Fiber Optics and Optical Communications
Fourier optics and optical signal processing
Fourier Optics and Signal Processing
General
Geometric Optics
Geometrical optics
Holographic reconstruction, display,and projection
Holography
Image processing
Image Processing and Machine Vision
Imaging Systems
Imaging Systems and Image Processing
Infrared and Terahertz Photonics
Instrumentation, measurement, and metrology
Instrumentation, Measurement, and Optical Sensing
Integral imaging
Integrate optics
Integrated Optics
Lasers and Laser Optics
Lasers, Optical Amplifiers, and Laser Optics
Letters
Light-matter Interaction
Machine Vision
Materials
Measurement
Medical and biological imaging
Medical optics and biotechnology
Metamaterials, plasmon polaritons, and waveguides in terahertz region
Microscopy
Microwave Photonics
Multiphoton processes
Nanophotonics
Nanophotonics, Metamaterials, and Plasmonics
Nolinear optics
Nonlinear Optics
optical computing
OPTICAL DATA STORAGE
Optical Design and Fabrication
optical design and fabrications
Optical devices
Optical divces
Optical Materials
Optical Sensing, Measurements, and Metrology
Optical trapping
Optics at Surfaces
Optics in Computing
Optics in Computing and Optical Data Storage
Optics in Interdisciplinary Research
Optoelectronics
Other Areas of Optics
Physical Optics
Plasmonics and Metamaterials
Quantum optics
Quantum Optics and Quantum Information
remote sensing
Remote Sensing and Sensors
Research Articles
Reviews
Scattering
Solar Energy and Photovoltaics
Sources and mechanisms of terahertz radiation
Special Issue on 20th Anniversary of Wuhan National Laboratory for Optoelectronics (WNLO)
Special Issue on 70th anniversary of National University of Defense Technology
Special Issue on Lithium Niobate Based Photonic Devices
Special Issue on Lithium Noibate Based Photonic Devices
Special Issue on Metal Halide Perovskite and Their Applications
Special Issue on OISE Major Jointly Established by Tianjin University and Nankai University
Special Issue on Optical Metasurfaces: Fundamentals and Applications
Special Issue on Spatiotemporal Optical Fields and Time-Varying Optical Materials
Special Issue on the 20th Anniversary of Wuhan National Laboratory for Optoelectronics (WNLO)
Spectroscopy
Spectroscopy, imaging, and sensing using terahertz radiation
Thin films
Thin Films and Optics at Surfaces
Ultrafast Optics
Ultrafast Optics and Attosecond/High-field Physics
Ultrafast Optics: fundamentals and applications
Underwater Wireless Optical Communication
vision and color
Vision, color, and visual
Vision, Color, and Visual Optics
Visual Optics and Displays
X-ray Optics