Review
Optics
Guoping Lin, Qinghai Song
Summary: The Kerr optical frequency comb, as a novel microcomb source, has been widely applied in various fields and requires resonator platforms with small mode volumes and high quality factors. This review focuses on recent progress in microcomb development, including interactions with Raman, Brillouin scattering, and second-order nonlinear processes, leading to Kerr frequency combs transferring to other spectral windows.
LASER & PHOTONICS REVIEWS
(2022)
Article
Chemistry, Multidisciplinary
Yoonsoo Rho, SeokJae Yoo, Daniel B. Durham, DongJun Kang, Andrew M. Minor, Costas P. Grigoropoulos
Summary: Nonlinear optical response is a useful tool for studying the properties of materials, but its weak signal and limited reach make it difficult to probe deep-subwavelength-scale nonlinear optics. In this study, we propose a new method using an SHG-active plasmonic nanotip to achieve efficient second harmonic generation (SHG) nanoscopy. Our simulations suggest that enhancing the nonlinear response of the sample or suppressing the tip's response can lead to a high near-field SHG contrast, providing evidence of quantum mechanical nonlinear energy transfer. Furthermore, this technique can be used to study nanoscale corrosion and other physicochemical phenomena.
Article
Optics
Zelin Hao, Wenwei Liu, Zhancheng Li, Zhi Li, Guangzhou Geng, Yanchun Wang, Hua Cheng, Hammad Ahmed, Xianzhong Chen, Junjie Li, Jianguo Tian, Shuqi Chen
Summary: Metasurfaces have shown great potential in optical wave manipulation but face challenges in multidimensional manipulation of harmonic waves generated by nonlinear metasurfaces. This study presents an efficient design strategy based on the hydrodynamic model of free electron dynamics, allowing for full complex-amplitude modulation of second harmonic generation. The proposed nonlinear metasurfaces demonstrate spin-selective SHG optical vortices with independent topological charges, opening up new possibilities for nonlinear metasurface applications in optical information and multifunctional integration.
LASER & PHOTONICS REVIEWS
(2021)
Article
Optics
Marc Jankowski, Carsten Langrock, Boris Desiatov, Marko Loncar, M. M. Fejer
Summary: We propose a new approach to supercontinuum generation and carrier-envelope-offset detection based on saturated second-order nonlinear interactions in dispersion-engineered nanowaveguides. The technique developed here broadens the interacting harmonics by forming stable bifurcations of the pulse envelopes due to an interplay between phase-mismatch and pump depletion. The scaling laws suggest that future realization based on this approach could enable supercontinuum generation with orders of magnitude less energy than current state-of-the-art devices.
Article
Engineering, Electrical & Electronic
Hauke Conradi, Almontaserbillah Hakmi, Moritz Kleinert, Lars Liebermeister, David de Felipe, Madeleine Weigel, Martin Kresse, Crispin Zawadzki, Bjoern Globisch, Norbert Keil, Ronald Freund, Martin Schell
Summary: In this study, second harmonic generation from 1550 to 775 nm was demonstrated in a polymer photonic integrated circuit via the hybrid integration of a periodically poled lithium niobate crystal. Fiber to fiber conversion efficiencies were found to be 0.03%/W for a continuous wave laser source and 100%/W for a femtosecond laser source. Additionally, third and fourth harmonic light at 517 and 388 nm was observed.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Ji-Liang Wu, Xiaohui Guo, Yadong Jiao, Xucheng Zhang, Ting Wang, Yue-De Yang, Jin-Long Xiao, Daming Zhang, Guanshi Qin, Yong-Zhen Huang
Summary: In this study, an octave-spanning 10-GHz optical comb is achieved using a directly-modulated microlaser, and the optical pulse width is further reduced to 140 fs in a fiber through optimal chirp compensation.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Fan Yang, Cristian Ciraci
Summary: We present a theoretical study on second-harmonic generation from a singular metasurface, which strongly interacts with incident light and generates intense surface polarization, resulting in the generation of second-harmonic field. By using transformation optics, the calculation of nonlinear optical response is simplified, and the dependence on the incident angle is weak, making it potentially useful for all-angle harmonic generation. Furthermore, we investigate the symmetry dependence of second-harmonic generation in the far field and demonstrate an enhanced conversion efficiency under normal incidence by breaking the surface inversion symmetry.
Article
Engineering, Electrical & Electronic
Fujian Yu, Runlin Miao, Ke Yin, Xin Zhang, Tian Jiang
Summary: In this paper, a two-stage nonlinear system is built to broaden a 12.5 GHz EO-comb. The system achieves significant spectral broadening and shows potential for application in parallel gas detection.
IEEE PHOTONICS JOURNAL
(2022)
Article
Engineering, Electrical & Electronic
Sruti Menon, Varun Raghunathan
Summary: We demonstrate second harmonic generation (SHG) enhancement in a resonant metasurface composed of amorphous silicon sub-wavelength gratings and an underlying gallium nitride (GaN) layer. The design and characterization of the sub-wavelength grating dimensions, spectral resonances, angular sensitivity, electric field, and non-linear polarization profiles are discussed. Experimental studies on the fabricated structures, including linear and nonlinear SHG properties, are also presented. The SHG spectral measurements show a 1300-fold enhancement for 1460 nm fundamental excitation, attributed to the trade-off between the in-plane to out-of-plane nonlinear polarization ratio and the decrease in resonance field strength.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2023)
Article
Nanoscience & Nanotechnology
Jingyang He, Seng Huat Lee, Francesco Naccarato, Guillaume Brunin, Rui Zu, Yuanxi Wang, Leixin Miao, Huaiyu Wang, Nasim Alem, Geoffroy Hautier, Gian-Marco Rignanese, Zhiqiang Mao, Venkatraman Gopalan
Summary: This study reports the bulk single crystals of SnP2S6 with a large nonlinear optical susceptibility, a large laser-induced damage threshold, and a wide transparency range, making it an outstanding candidate for infrared laser applications.
Article
Mathematics
Yernat M. Assylbekov, Ting Zhou
Summary: In this paper, an inverse boundary value problem of electromagnetism with nonlinear Second Harmonic Generation (SHG) process is considered. The unique determination of the electromagnetic material parameters and the SHG susceptibility parameter of the medium is shown by making electromagnetic measurements on the boundary. The case of interest is when a frequency is fixed.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2021)
Article
Chemistry, Multidisciplinary
Chao Wu, Xingxing Jiang, Lin Lin, Yilei Hu, Tianhui Wu, Zheshuai Lin, Zhipeng Huang, Mark G. Humphrey, Chi Zhang
Summary: The study presents the synthesis of a polar NLO vanadate Cs4V8O22 (CVO) with excellent optical properties and strong second-harmonic generation effects achieved through hydrothermal synthesis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Materials Science, Multidisciplinary
Tingting Liu, Xinyuan Fang, Shuyuan Xiao
Summary: Engineering nonlinear optical processes in dielectric nanostructures using chalcogenide phase-change material allows for efficient tuning of second-harmonic generation processes. The nonlinear SHG signal from nanoantennas can be enhanced and modulated by optically induced Mie-type resonances and the amorphous-to-crystalline phase change in GST. By adjusting the refractive index of GST, a maximum modulation depth of up to 540% is demonstrated, showing the potential for control of optical nonlinearity and smart designing of tunable nonlinear optical devices.
Article
Optics
Mathias Hedegaard Kristensen, Peter Kjaer Kristensen, Kjeld Pedersen, Esben Skovsen
Summary: This communication demonstrates a new characterization technique that combines FT spectroscopy and SHG to achieve high spectral resolution with broadband femtosecond laser pulses. By showcasing the capabilities of the method with the strong and narrow exciton resonances of ZnO, FT-SHG offers high reproducibility and resolution within the bandwidth of the input pulse.
OPTICS COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Bryson Krause, Dhananjay Mishra, Jiyang Chen, Christos Argyropoulos, Thang Hoang
Summary: This study demonstrates enhanced second-harmonic generation and second-order nonlinear exciton-polariton strong coupling response using plasmonic nanopatch antennas (NPAs), providing important insights for nonlinear control of light-matter interactions in optical engineering and information processing.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Optics
Nicola Corrias, Tecla Gabbrielli, Paolo de Natale, Luigi Consolino, Francesco Cappelli
Summary: This article demonstrates the applicability of quantum cascade laser frequency combs in free-space optical communication. The analog signal is transferred using the spontaneously-generated intermodal beat note of the frequency comb as the carrier for frequency modulation. It also showcases the potential for parallel transmission of independent digital signals through amplitude modulation.
Article
Optics
Roberto Aiello, Valentina Di Sarno, Maria Giulia Delli Santi, Maurizio De Rosa, Iolanda Ricciardi, Giovanni Giusfredi, Paolo De Natale, Luigi Santamaria, Pasquale Maddaloni
Summary: This study introduces a high-detection-sensitivity saturated-absorption cavity ring-down (SCAR) technique for Lamb-dip spectroscopy of rovibrational molecular transitions in the near-infrared region. The analysis of acetylene spectra at 6562 cm(-1) is based on a specially developed theoretical model, resulting in a 40% reduction in linewidth and a 90% increase in signal-to-noise ratio compared to conventional methods, ultimately achieving a low uncertainty for absolute line-center frequency and relative line strength measurements.
PHOTONICS RESEARCH
(2022)
Article
Multidisciplinary Sciences
Maria Giulia Delli Santi, Giacomo Insero, Saverio Bartalini, Pablo Cancio, Federico Carcione, Iacopo Galli, Giovanni Giusfredi, Davide Mazzotti, Antonio Bulgheroni, Ana Isabel Martinez Ferri, Rafael Alvarez-Sarandes, Laura Aldave de las Heras, Vincenzo Rondinella, Paolo De Natale
Summary: The precise determination of radionuclide inventory in radioactive waste streams is crucial for nuclear waste management. This paper demonstrates the use of laser-based saturated-absorption cavity ring-down (SCAR) spectroscopic technique as an accurate alternative for C-14 content determination in nuclear waste. The results show consistent measurements compared to accelerator mass spectrometry (AMS), indicating the maturity and accuracy of SCAR for C-14 analysis in concrete and graphite samples.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Editorial Material
Chemistry, Physical
Agnes Perrin, Johannes Orphal, Therese Huet, Paolo de Natale, Frederic Merkt, Stephan Schlemmer, Martin Quack, Stefan Willitsch
Article
Optics
I. O. L. A. N. D. A. Ricciardi, P. A. S. Q. U. A. L. E. Maddaloni, P. A. O. L. O. DE Natale, M. I. R. O. Erkintalo, T. O. B. I. A. S. Hansson, A. D. Y. Arie, S. T. E. F. A. N. Wabnitz, M. A. U. R. I. Z. I. O. DE Rosa
Summary: We report on the experimental realization and systematic study of optical frequency comb generation in doubly resonant intracavity second harmonic generation. By controlling the resonance condition and laser detuning, we observe steady comb emission and identify the significant role of thermal effects in comb dynamics. Numerical simulations agree well with experimental observations. This study provides a framework for exploring the dynamics of doubly resonant second harmonic generation systems and aids in the design of chip-scale comb generators.
Article
Optics
Marco Seminara, Tecla Gabbrielli, Nicola Corrias, Simone Borri, Luigi Consolino, Marco Meucci, Paolo de Natale, Francesco Cappelli, Jacopo Catani
Summary: The recent development of Quantum Cascade Lasers (QCLs) has opened up new opportunities for Free Space Optical (FSO) communication systems operating in the mid-infrared (mid-IR) wavelength range. This study focuses on analyzing noise regimes in realistic mid-IR FSO systems based on QCLs, using a novel FSO testbed operating at 4.7 pm. The analysis reveals two distinct noise regions that can be controlled, and the experimental data combined with atmospheric channel loss predictions demonstrate the potential for error-free communication at effective distances up to 8 km in low visibility conditions of 1 km.
Article
Acoustics
Zhen Wang, Qiang Wang, Hui Zhang, Simone Borri, Iacopo Galli, Angelo Sampaolo, Pietro Patimisco, Vincenzo Luigi Spagnolo, Paolo De Natale, Wei Ren
Summary: This study develops a gas sensor based on doubly resonant photoacoustic spectroscopy, which enhances both the acoustic and optical waves using combined optical and acoustic resonators. The sensor achieves high sensitivity and a wide dynamic range, making it capable of detecting low concentrations of gases.
Article
Optics
Elisa Riccardi, Valentino Pistore, Luigi Consolino, Alessia Sorgi, Francesco Cappelli, Roberto Eramo, Paolo De Natale, Lianhe Li, Alexander Giles Davies, Edmund H. Linfield, Miriam S. Vitiello
Summary: In this paper, a technological method for achieving broad FC operation across the entire THz frequency range is proposed, using multistack quantum cascade lasers and multilayer graphene films. The experimental characterization of the QCL FC confirms its metrological nature.
LASER & PHOTONICS REVIEWS
(2023)
Article
Acoustics
Hui Zhang, Zhen Wang, Qiang Wang, Simone Borri, Iacopo Galli, Angelo Sampaolo, Pietro Patimisco, Vincenzo Luigi Spagnolo, Paolo De Natale, Wei Ren
Summary: We developed a highly sensitive hydrogen sulfide (H2S) gas sensor using the doubly resonant photoacoustic spectroscopy technique and a near-infrared laser. The sensor achieved a minimum detection limit of 10 part per billion in concentration and a normalized noise equivalent absorption coefficient of 8.9 x 10(-12) W cm(-1) Hz(-1/2) by targeting the R(4) transition of H2S. A laser-cavity-molecule locking strategy was proposed to enhance sensor stability for fast measurement when dealing with external disturbances. A comparison with state-of-the-art H2S sensors using various spectroscopic techniques confirmed the record sensitivity achieved in this work.
Article
Optics
Fabrizio Sgobba, Deborah Katia Pallotti, Arianna Elefante, Stefano Dello Russo, Daniele Dequal, Mario Siciliani de Cumis, Luigi Santamaria Amato
Summary: The use of statistical estimation theory is increasingly popular in improving the performance of measurement apparatus. Recent experiments in Hong Ou Mandel interferometry set new records in time delay and polarization measurement. Extending these experiments to the telecom range, we aim to unlock the full potential of this approach in fiber-coupled devices of up to hundreds of kilometers long. Our measurement achieves the Cramer-Rao bound with an Allan deviation of 0.002 degs in 1 hour.
Article
Multidisciplinary Sciences
Luigi Santamaria Amato, Deborah Katia Pallotti, Mario Siciliani de Cumis, Daniele Dequal, Andrea Andrisani, Sergei Slussarenko
Summary: Nonlocality, a key conflict between Quantum Physics and Relativity, has troubled physicists even more than realism as it suggests the possibility of superluminal communication, also known as Einsteinian Spooky action at a distance. Since 2000, various tests have been conducted to determine the lower bounds of the Spooky action at a distance velocity (c beta(t,max)). These tests typically involve Bell Tests performed in kilometer-long experimental setups, with careful adjustments and assumptions dictated by the experimental conditions, in order to improve the constraints.
SCIENTIFIC REPORTS
(2023)
Article
Optics
Fabrizio Sgobba, Arianna Elefante, Stefano Dello Russo, Mario Siciliani de Cumis, Luigi Santamaria Amato
Summary: We have developed a highly sensitive optical sensor for circular birefringence using a heralded photon source. This sensor can be utilized for chirality measurements and is suitable for delicate biological samples or metrological applications that require low light intensity. Through finding the optimal operational condition, calibrating the sensor, and testing its performance over a long acquisition time, we achieved excellent stability and a sub-ppm birefringence detection limit (for a 100 μm sample), which also opens up possibilities for fundamental physics tests.
Article
Optics
B. Chomet, T. Gabbrielli, D. Gacemi, F. Cappelli, L. Consolino, P. De Natale, F. Kapsalidis, A. Vasanelli, Y. Todorov, J. Faist, C. Sirtori
Summary: In quantum cascade laser frequency combs, the intensity distribution of the optical spectrum can be split into two well-separated lobes of longitudinal modes that, even when far apart, have a common phase relation and preserve equal frequency separation. The temporal dynamics of two lasers emitting at 4.4 and 8.1 mu m operating in this bilobed regime are investigated. The laser intensity shows a peculiar temporal behavior associated with the spectral features whereby, every half a round-trip, the total emitted power switches from one lobe to the other, with a perfect temporal anti-correlation.
Article
Quantum Science & Technology
Domenico Ribezzo, Mujtaba Zahidy, Ilaria Vagniluca, Nicola Biagi, Saverio Francesconi, Tommaso Occhipinti, Leif K. Oxenlowe, Martin Loncaric, Ivan Cvitic, Mario Stipcevic, Ziga Pusavec, Rainer Kaltenbaek, Anton Ramsak, Francesco Scazza, Giorgio Giorgetti, Francesco Scazza, Angelo Bassi, Paolo De Natale, Francesco Saverio Cataliotti, Massimo Inguscio, Davide Bacco, Alessandro Zavatta
Summary: It has been around 40 years since the possibility of using quantum physics to enhance communications safety was introduced. Nowadays, quantum key distribution (QKD) has become a mature technology, drawing the attention of various entities, including states, military forces, banks, and private corporations. This work successfully deploys QKD on consumer technology by utilizing deployed optical fibers to create a quantum network connecting three different countries. The experimental results, along with the interest from an important international political event, highlight the maturity of QKD technology, making it a potential candidate for consumer applications in the near future.
ADVANCED QUANTUM TECHNOLOGIES
(2023)