Pub Date : 2024-09-23Epub Date: 2024-09-09DOI: 10.1364/OE.531468
Takuma Morimoto, JoãO M M Linhares, Sérgio M C Nascimento, Hannah E Smithson
Color supports object identification. However, two objects that differ in color under one light can appear indiscriminable under a second light, a phenomenon known as illuminant metamerism. Past studies evaluated the frequency of illuminant metamerism only under single, uniform illuminants. Here we used computer-graphics techniques to simulate a pair of planar surfaces placed under newly measured hyperspectral illumination maps that quantify the directional variability of real-world lighting environments. We counted the instances of illuminant metamerism that can be solved simply by viewing surfaces tilted to a different direction. Results show that most instances of illuminant metamerism can in theory be resolved for both trichromatic and dichromatic observers, suggesting that the physical directional variability available in natural lighting environments substantially mitigates the biological limitations of trichromacy or dichromacy.
{"title":"How many surfaces can you distinguish by color? Real environmental lighting increases discriminability of surface colors.","authors":"Takuma Morimoto, JoãO M M Linhares, Sérgio M C Nascimento, Hannah E Smithson","doi":"10.1364/OE.531468","DOIUrl":"10.1364/OE.531468","url":null,"abstract":"<p><p>Color supports object identification. However, two objects that differ in color under one light can appear indiscriminable under a second light, a phenomenon known as illuminant metamerism. Past studies evaluated the frequency of illuminant metamerism only under single, uniform illuminants. Here we used computer-graphics techniques to simulate a pair of planar surfaces placed under newly measured hyperspectral illumination maps that quantify the directional variability of real-world lighting environments. We counted the instances of illuminant metamerism that can be solved simply by viewing surfaces tilted to a different direction. Results show that most instances of illuminant metamerism can in theory be resolved for both trichromatic and dichromatic observers, suggesting that the physical directional variability available in natural lighting environments substantially mitigates the biological limitations of trichromacy or dichromacy.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7616623/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142308283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mingle Qiao, Yongfang Xie, Shihao Kang, Jin Wang, Changhe Zhou
In this paper, a transmission two-dimensional (2D) all-dielectric grating with cuboid arrays is proposed, which has high diffraction efficiency and good polarization independence under Littrow mounting conditions at an incident wavelength of 780 nm. The optimization results indicate that when the incident wavelength is 780 nm, the diffraction efficiency of the (−1, 0) order of transverse electric (TE) and transverse magnetic (TM) polarizations can reach 98.62% and 98.23%, respectively, with the polarization-dependent loss (PDL) of 0.017 dB. To the best of our knowledge, high-efficiency polarization-independent 2D transmission grating with a simpler and more effective structure is proposed for the first time, which demonstrates significant enhancements in bandwidth and manufacturing tolerances while maintaining high diffraction efficiency. The results suggest that the grating has great potential for applications in high-precision displacement measurements such as grating interferometers.
{"title":"Polarization-independent and high-efficiency 2D dielectric transmission grating under Littrow incidence","authors":"Mingle Qiao, Yongfang Xie, Shihao Kang, Jin Wang, Changhe Zhou","doi":"10.1364/oe.537907","DOIUrl":"https://doi.org/10.1364/oe.537907","url":null,"abstract":"In this paper, a transmission two-dimensional (2D) all-dielectric grating with cuboid arrays is proposed, which has high diffraction efficiency and good polarization independence under Littrow mounting conditions at an incident wavelength of 780 nm. The optimization results indicate that when the incident wavelength is 780 nm, the diffraction efficiency of the (−1, 0) order of transverse electric (TE) and transverse magnetic (TM) polarizations can reach 98.62% and 98.23%, respectively, with the polarization-dependent loss (PDL) of 0.017 dB. To the best of our knowledge, high-efficiency polarization-independent 2D transmission grating with a simpler and more effective structure is proposed for the first time, which demonstrates significant enhancements in bandwidth and manufacturing tolerances while maintaining high diffraction efficiency. The results suggest that the grating has great potential for applications in high-precision displacement measurements such as grating interferometers.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leander Siegle, Dajie Xie, Corey A. Richards, Paul V. Braun, Harald Giessen
We demonstrate focusing as well as imaging using diffractive microoptics, manufactured by two-photon polymerization grayscale lithography (2GL), that have been 3D printed into porous silicon oxide. While typical doublet lens systems require support structures that hold the lenses in place, our optics are held by the porous media itself, decreasing both the fabrication time and design constraints while increasing the optically active area. Compared to the typical two-photon polymerization fabrication process, 2GL offers better shape accuracy while simultaneously increasing throughput. To showcase 2GL manufactured optics in porous media, we fabricate singlet diffractive lenses with a diameter of 500 µm and numerical apertures of up to 0.6. We measure the intensity distribution in the focal plane, and along the optical axis. Furthermore, we design and fabricate a doublet lens system for imaging purposes with a diameter of 600 µm and thinner than 60 µm. We examine the imaging performance with a USAF 1951 resolution test chart and determine the resolution to be 287 lp/mm. 3D printing in porous SiO2 thus holds great promise for future complex and unconventional microoptical solutions.
{"title":"Diffractive microoptics in porous silicon oxide by grayscale lithography","authors":"Leander Siegle, Dajie Xie, Corey A. Richards, Paul V. Braun, Harald Giessen","doi":"10.1364/oe.538142","DOIUrl":"https://doi.org/10.1364/oe.538142","url":null,"abstract":"We demonstrate focusing as well as imaging using diffractive microoptics, manufactured by two-photon polymerization grayscale lithography (2GL), that have been 3D printed into porous silicon oxide. While typical doublet lens systems require support structures that hold the lenses in place, our optics are held by the porous media itself, decreasing both the fabrication time and design constraints while increasing the optically active area. Compared to the typical two-photon polymerization fabrication process, 2GL offers better shape accuracy while simultaneously increasing throughput. To showcase 2GL manufactured optics in porous media, we fabricate singlet diffractive lenses with a diameter of 500 µm and numerical apertures of up to 0.6. We measure the intensity distribution in the focal plane, and along the optical axis. Furthermore, we design and fabricate a doublet lens system for imaging purposes with a diameter of 600 µm and thinner than 60 µm. We examine the imaging performance with a USAF 1951 resolution test chart and determine the resolution to be 287 lp/mm. 3D printing in porous SiO<jats:sub>2</jats:sub> thus holds great promise for future complex and unconventional microoptical solutions.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiyue Zhang, Yuchen Wang, Weibo Wu, Tinghui An, Yiguang Jiang, Jintai Fan, Benxue Jiang, Pinghua Tang, Gianluca Galzerano, Paolo Laporta, Long Zhang
Soliton molecules, or soliton bound states, are envisioned to make far-reaching changes in both fundamental research and applications. Here, we report on the generation and precision manipulation of soliton molecules based on a Kerr-lens mode-locked single-crystal Cr:ZnS laser at 2.4 µm. In the classical soliton regime, self-starting near-transform-limited pulses with a duration of 37 fs, less than 5 optical cycles, have been obtained at a repetition frequency of 173 MHz and an average output power of 572 mW. By fine-tuning the cavity group-delay dispersion profile, bi-soliton states with pulse durations between 55 fs and 98 fs with temporal separations between 348 fs and 604 fs have been observed and characterized. These are the shortest pulse duration and separation of soliton molecules reported so far in the mid-infrared region, to the best of our knowledge. With the ability of precision manipulation of soliton molecules generated on a sub-100-fs timescale, the tunable mid-infrared soliton molecule source paves the way for applications in the fields of telecommunications and ultrafast laser technologies.
{"title":"Mid-infrared ultrafast soliton molecules from a few-cycle Cr:ZnS laser","authors":"Xiyue Zhang, Yuchen Wang, Weibo Wu, Tinghui An, Yiguang Jiang, Jintai Fan, Benxue Jiang, Pinghua Tang, Gianluca Galzerano, Paolo Laporta, Long Zhang","doi":"10.1364/oe.537071","DOIUrl":"https://doi.org/10.1364/oe.537071","url":null,"abstract":"Soliton molecules, or soliton bound states, are envisioned to make far-reaching changes in both fundamental research and applications. Here, we report on the generation and precision manipulation of soliton molecules based on a Kerr-lens mode-locked single-crystal Cr:ZnS laser at 2.4 µm. In the classical soliton regime, self-starting near-transform-limited pulses with a duration of 37 fs, less than 5 optical cycles, have been obtained at a repetition frequency of 173 MHz and an average output power of 572 mW. By fine-tuning the cavity group-delay dispersion profile, bi-soliton states with pulse durations between 55 fs and 98 fs with temporal separations between 348 fs and 604 fs have been observed and characterized. These are the shortest pulse duration and separation of soliton molecules reported so far in the mid-infrared region, to the best of our knowledge. With the ability of precision manipulation of soliton molecules generated on a sub-100-fs timescale, the tunable mid-infrared soliton molecule source paves the way for applications in the fields of telecommunications and ultrafast laser technologies.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ultan J. Daly, Fortune Iga, Aleksandr Boldin, Adam J. Vallance, Mitchell A. Cox, Martin P. J. Lavery
Free-space optical (FSO) communication systems are acutely affected by the pointing issues and distortions that result from mechanical instability and environmental factors such as turbulence. These distortions have generally prevented single-mode bi-directional systems from being deployed without adaptive optics due to high optical losses. We investigate and compare the performance of both step and graded index multi-mode fibers for bi-directional communications over an emulated 400 m FSO channel. We propose that OM5 graded index fiber will simultaneously provide a near Gaussian optical transmission mode and a factor of greater than 5 increase in the field of view compared to single-mode fiber. We demonstrate that OM5 can support an error-free throughput of 10 Gbps for low-turbulence (D/r0 = 3) and 9.1 Gbps for high-turbulence (D/r0 = 9) using commercial bi-directional small form-factor pluggable (SFP+) transceivers with no adaptive optical components.
{"title":"Low-complexity turbulence resilience enabled by a multi-mode bi-directional transceiver","authors":"Ultan J. Daly, Fortune Iga, Aleksandr Boldin, Adam J. Vallance, Mitchell A. Cox, Martin P. J. Lavery","doi":"10.1364/oe.532749","DOIUrl":"https://doi.org/10.1364/oe.532749","url":null,"abstract":"Free-space optical (FSO) communication systems are acutely affected by the pointing issues and distortions that result from mechanical instability and environmental factors such as turbulence. These distortions have generally prevented single-mode bi-directional systems from being deployed without adaptive optics due to high optical losses. We investigate and compare the performance of both step and graded index multi-mode fibers for bi-directional communications over an emulated 400 m FSO channel. We propose that OM5 graded index fiber will simultaneously provide a near Gaussian optical transmission mode and a factor of greater than 5 increase in the field of view compared to single-mode fiber. We demonstrate that OM5 can support an error-free throughput of 10 Gbps for low-turbulence (<jats:italic toggle=\"yes\">D</jats:italic>/<jats:italic toggle=\"yes\">r</jats:italic><jats:sub>0</jats:sub> = 3) and 9.1 Gbps for high-turbulence (<jats:italic toggle=\"yes\">D</jats:italic>/<jats:italic toggle=\"yes\">r</jats:italic><jats:sub>0</jats:sub> = 9) using commercial bi-directional small form-factor pluggable (SFP+) transceivers with no adaptive optical components.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142184762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Phase retrieval based on data-driven deep learning (DL) is a suitable decoding method for phase-modulated holographic data storage (HDS). Once the DL network is trained, the phase can be directly retrieved from the corresponding diffraction intensity image with high data transfer rate and low bit error rate. Traditional data-driven DL-based phase retrieval requires a large number of known samples for training, which is usually laborious for practical applications such as HDS. In the paper, we propose an image segmentation method based on image features, leading to about 54 times reduction in the number of original sample pairs (OSP) for training DL network. The proposed method is easy to implement in practical situations of HDS.
{"title":"Image segmentation of phase-modulated holographic data storage based on deep learning","authors":"Ruixian Chen, Jinyu Wang, Shaodong Zhang, Rongquan Fan, Dakui Lin, Xiong Li, Jihong Zheng, Qiang Cao, Jianying Hao, Xiao Lin, Xiaodi Tan","doi":"10.1364/oe.536783","DOIUrl":"https://doi.org/10.1364/oe.536783","url":null,"abstract":"Phase retrieval based on data-driven deep learning (DL) is a suitable decoding method for phase-modulated holographic data storage (HDS). Once the DL network is trained, the phase can be directly retrieved from the corresponding diffraction intensity image with high data transfer rate and low bit error rate. Traditional data-driven DL-based phase retrieval requires a large number of known samples for training, which is usually laborious for practical applications such as HDS. In the paper, we propose an image segmentation method based on image features, leading to about 54 times reduction in the number of original sample pairs (OSP) for training DL network. The proposed method is easy to implement in practical situations of HDS.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142184773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quan Li, Li Pei, Bing Bai, Jianshuai Wang, Bowen Bai, Xiaoyan Zuo, Juan Sui, Fei Dong
In the next generation of Elastic Optical Networks, various modulation formats exhibit varying degrees of sensitivity to channel impairments during transmission. To adopt appropriate channel equalization schemes at the receiver, it is essential to perform modulation format identification prior to the receiver, followed by the adjustment of receiver parameters and types based on the recognition results. A system based on a 52-node integrated photonic reservoir chip and untrained K-nearest neighbors (KNN) algorithm is proposed for the recognition of OOK, PAM4, QPSK, and BPSK modulation formats in optical channel transmission. Its performance is validated across optical signal-to-noise ratios ranging from 8 to 23 dB, taking into account the dispersion damage of 20 km single-mode fiber transmission. In all tested scenarios, the recognition accuracy consistently surpasses 96.25%, showcasing a 14.93% improvement over prior works and an 82.81% enhancement over traditional algorithmic methods under identical conditions. The study explores the impact of different waveguide delay amounts, random phases, and algorithm K values on recognition accuracy.
在下一代弹性光网络中，各种调制格式在传输过程中对信道损伤表现出不同程度的敏感性。为了在接收器上采用适当的信道均衡方案，必须在接收器之前进行调制格式识别，然后根据识别结果调整接收器参数和类型。本文提出了一种基于 52 节点集成光子存储芯片和未经训练的 K 近邻（KNN）算法的系统，用于识别光信道传输中的 OOK、PAM4、QPSK 和 BPSK 调制格式。考虑到 20 千米单模光纤传输的色散破坏，在 8 至 23 dB 的光信噪比范围内对其性能进行了验证。在所有测试场景中，识别准确率始终超过 96.25%，与之前的研究相比提高了 14.93%，与相同条件下的传统算法相比提高了 82.81%。研究探讨了不同波导延迟量、随机相位和算法 K 值对识别准确率的影响。
{"title":"Modulation format identification in elastic optical networks using integrated photonic reservoir computing and untrained K-nearest neighbors algorithm","authors":"Quan Li, Li Pei, Bing Bai, Jianshuai Wang, Bowen Bai, Xiaoyan Zuo, Juan Sui, Fei Dong","doi":"10.1364/oe.533608","DOIUrl":"https://doi.org/10.1364/oe.533608","url":null,"abstract":"In the next generation of Elastic Optical Networks, various modulation formats exhibit varying degrees of sensitivity to channel impairments during transmission. To adopt appropriate channel equalization schemes at the receiver, it is essential to perform modulation format identification prior to the receiver, followed by the adjustment of receiver parameters and types based on the recognition results. A system based on a 52-node integrated photonic reservoir chip and untrained K-nearest neighbors (KNN) algorithm is proposed for the recognition of OOK, PAM4, QPSK, and BPSK modulation formats in optical channel transmission. Its performance is validated across optical signal-to-noise ratios ranging from 8 to 23 dB, taking into account the dispersion damage of 20 km single-mode fiber transmission. In all tested scenarios, the recognition accuracy consistently surpasses 96.25%, showcasing a 14.93% improvement over prior works and an 82.81% enhancement over traditional algorithmic methods under identical conditions. The study explores the impact of different waveguide delay amounts, random phases, and algorithm K values on recognition accuracy.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142184783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yiliang Wang, Yi Zheng, Chenlei Fang, Haobin Shi, Wei Pan
Continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) can defend all detection-side attacks effectively. Therefore, the source side is the final battlefield for performing quantum hacking attacks. This paper investigates the practical security of a CV-MDI QKD system under a light-injection attack. Here, we first describe two different light-injection attacks, i.e., the induced-photorefractive attack and the strong-power injection attack. Then, we consider three attack cases where Eve only attacks one of the parties or both parties of the CV-MDI QKD system. Based on the analysis of the parameter estimation, we find that the legitimate communication parties will overestimate the secret key rate of the system under the effect of a light-injection attack. This opens a security loophole for Eve to successfully obtain secret key information in a practical CV-MDI QKD system. In particular, compared to the laser-damage attack, the above attacks use a lower power of injected light and have a more serious effect on the security of the system. To eliminate the above effects, we can enhance the practical security of the system by doping the lithium niobate material with various impurities or by using protective devices, such as optical isolators, circulators, optical power limiters, and narrow-band filters. Apart from these, we can also use an intensity monitor or a photodetector to detect the light-injection attack.
{"title":"Light-injection attack against practical continuous-variable measurement-device-independent quantum key distribution systems","authors":"Yiliang Wang, Yi Zheng, Chenlei Fang, Haobin Shi, Wei Pan","doi":"10.1364/oe.537325","DOIUrl":"https://doi.org/10.1364/oe.537325","url":null,"abstract":"Continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) can defend all detection-side attacks effectively. Therefore, the source side is the final battlefield for performing quantum hacking attacks. This paper investigates the practical security of a CV-MDI QKD system under a light-injection attack. Here, we first describe two different light-injection attacks, i.e., the induced-photorefractive attack and the strong-power injection attack. Then, we consider three attack cases where Eve only attacks one of the parties or both parties of the CV-MDI QKD system. Based on the analysis of the parameter estimation, we find that the legitimate communication parties will overestimate the secret key rate of the system under the effect of a light-injection attack. This opens a security loophole for Eve to successfully obtain secret key information in a practical CV-MDI QKD system. In particular, compared to the laser-damage attack, the above attacks use a lower power of injected light and have a more serious effect on the security of the system. To eliminate the above effects, we can enhance the practical security of the system by doping the lithium niobate material with various impurities or by using protective devices, such as optical isolators, circulators, optical power limiters, and narrow-band filters. Apart from these, we can also use an intensity monitor or a photodetector to detect the light-injection attack.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142184763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yang Yu, Biao Ba, Wenlong Tian, Geyang Wang, Hui Tong, Yulong Su, Zhiyi Wei, Xiaodong Xu, Jiangfeng Zhu
In this paper, we present the demonstration of a cavity-dumped Kerr-lens mode-locked femtosecond oscillator based on an Yb:CALYO crystal for the first time. With the assistance of an SESAM, the Kerr-lens mode-locked Yb:CALYO laser delivered pulses with an average power of 2.8 W at a repetition rate of 61.3 MHz, corresponding to a pulse energy of 45.6 nJ. By employing a Pockels Cell consisting of dual β-BBO crystals and a thin film polarizer for cavity dumping, laser pulses of 280 nJ were achieved at both 1 MHz and 10 kHz repetition rates. The shortest pulse duration measured was 233 fs without external compression, resulting in a peak power of 1.06 MW.
{"title":"Cavity-dumped femtosecond Yb:CALYO laser based on SESAM assisted Kerr-lens mode locking","authors":"Yang Yu, Biao Ba, Wenlong Tian, Geyang Wang, Hui Tong, Yulong Su, Zhiyi Wei, Xiaodong Xu, Jiangfeng Zhu","doi":"10.1364/oe.537391","DOIUrl":"https://doi.org/10.1364/oe.537391","url":null,"abstract":"In this paper, we present the demonstration of a cavity-dumped Kerr-lens mode-locked femtosecond oscillator based on an Yb:CALYO crystal for the first time. With the assistance of an SESAM, the Kerr-lens mode-locked Yb:CALYO laser delivered pulses with an average power of 2.8 W at a repetition rate of 61.3 MHz, corresponding to a pulse energy of 45.6 nJ. By employing a Pockels Cell consisting of dual β-BBO crystals and a thin film polarizer for cavity dumping, laser pulses of 280 nJ were achieved at both 1 MHz and 10 kHz repetition rates. The shortest pulse duration measured was 233 fs without external compression, resulting in a peak power of 1.06 MW.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142184764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polarization and phase devices for terahertz waves have important applications in terahertz detection, imaging, communication, etc. Spatially variable metal gratings can be used for broad-spectrum, miniaturized, and low-cost terahertz polarization and phase modulation devices. Based on the effective dielectric constant and the theory of light propagation in multilayer media, we obtain the relationship between the transmittance and extinction ratio and the parameters such as the duty cycle of the metal grating, the frequency of the incident terahertz wave, the angle of incidence, the thickness of the metal grating, the refractive index of the substrate, and the thickness of the substrate. We propose a method of designing a spatially variable metal grating located on a transparent substrate. The designed spatially variable metal grating is also used to modulate the terahertz spatial polarization and phase to generate terahertz optical fields whose polarization and phase change simultaneously in space, such as azimuthally vector vortex terahertz optical fields, radially vector vortex terahertz optical fields, and so on. This will have important applications in terahertz time-domain spectroscopic detection, terahertz time-domain spectroscopic imaging, terahertz time-domain near-field microscopic imaging, terahertz communication, and so on.
{"title":"Design terahertz polarizers and vector polarized vortex terahertz wave generators based on the effective dielectric constant of metal gratings","authors":"Mengqiang Cai, Zhixu Wu, Weichao Yan, Jiangtao Lei, Yong Xia, Rongxin Tang","doi":"10.1364/oe.530489","DOIUrl":"https://doi.org/10.1364/oe.530489","url":null,"abstract":"Polarization and phase devices for terahertz waves have important applications in terahertz detection, imaging, communication, etc. Spatially variable metal gratings can be used for broad-spectrum, miniaturized, and low-cost terahertz polarization and phase modulation devices. Based on the effective dielectric constant and the theory of light propagation in multilayer media, we obtain the relationship between the transmittance and extinction ratio and the parameters such as the duty cycle of the metal grating, the frequency of the incident terahertz wave, the angle of incidence, the thickness of the metal grating, the refractive index of the substrate, and the thickness of the substrate. We propose a method of designing a spatially variable metal grating located on a transparent substrate. The designed spatially variable metal grating is also used to modulate the terahertz spatial polarization and phase to generate terahertz optical fields whose polarization and phase change simultaneously in space, such as azimuthally vector vortex terahertz optical fields, radially vector vortex terahertz optical fields, and so on. This will have important applications in terahertz time-domain spectroscopic detection, terahertz time-domain spectroscopic imaging, terahertz time-domain near-field microscopic imaging, terahertz communication, and so on.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142184774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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