Pub Date : 2024-04-16DOI: 10.1088/1612-202x/ad3a59
V L Gorshenin
We show that injecting a light pulse prepared in the Shrödinger cat quantum state into the dark port of a two-arm interferometer, it is possible to detect a given phase shift unambiguously. The value of this phase shift is inversely proportional to the amplitudes of both the classical carrier light and the Shrödinger cat state. However, an unconventional detection procedure is required for this purpose. By measuring the number of photons at the output dark port, it is possible to detect the phase shift with a vanishing ‘false positive’ probability. The ‘false negative’ probability in this case decreases as the amplitude of the Schrödinger cat state increases and, for reasonable values of this amplitude, can be made less than about 0.1.
{"title":"Using Schrödinger cat quantum state for detection of a given phase shift","authors":"V L Gorshenin","doi":"10.1088/1612-202x/ad3a59","DOIUrl":"https://doi.org/10.1088/1612-202x/ad3a59","url":null,"abstract":"We show that injecting a light pulse prepared in the Shrödinger cat quantum state into the dark port of a two-arm interferometer, it is possible to detect a given phase shift unambiguously. The value of this phase shift is inversely proportional to the amplitudes of both the classical carrier light and the Shrödinger cat state. However, an unconventional detection procedure is required for this purpose. By measuring the number of photons at the output dark port, it is possible to detect the phase shift with a vanishing ‘false positive’ probability. The ‘false negative’ probability in this case decreases as the amplitude of the Schrödinger cat state increases and, for reasonable values of this amplitude, can be made less than about 0.1.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140615419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-04-10DOI: 10.1088/1612-202x/ad3816
A A Sviridova, A S Shchekin, V N Petrovskiy, A A Ivanov, M M Berdnikova
In this paper, a study of the influence of laser processing parameters with pulsed nanosecond laser radiation on the degree of metallization and the quality of the metallized surface of aluminum nitride ceramics is presented. Experiments were carried out to create conductive structures with the lowest resistance using direct laser metallization. The dependences of resistance on duration, pulse overlap, and laser fluence were obtained and analyzed, and changes in surface roughness were considered. In addition, the composition of the surface of laser-metallized ceramics was studied using energy-dispersive x-ray spectroscopy. As a result, it was shown that the resistance is inversely proportional to the square root of the pulse duration, the thermal diffusion length was estimated as lT = 8.2 μm for 200 ns and lT = 1.2 μm for 4 ns, and the presence of optimal values of pulse overlap Oy (scanning direction) equal to 50% and pulse overlap Ox (step direction) equal to 96% and 99.7% for pulse durations of 200 and 4 ns, respectively, was determined. The choice of optimal pulse overlaps with the highest laser fluence allowed us to obtain the minimum resistance value with maximum performance.
{"title":"Direct nanosecond laser metallization of AlN ceramics","authors":"A A Sviridova, A S Shchekin, V N Petrovskiy, A A Ivanov, M M Berdnikova","doi":"10.1088/1612-202x/ad3816","DOIUrl":"https://doi.org/10.1088/1612-202x/ad3816","url":null,"abstract":"In this paper, a study of the influence of laser processing parameters with pulsed nanosecond laser radiation on the degree of metallization and the quality of the metallized surface of aluminum nitride ceramics is presented. Experiments were carried out to create conductive structures with the lowest resistance using direct laser metallization. The dependences of resistance on duration, pulse overlap, and laser fluence were obtained and analyzed, and changes in surface roughness were considered. In addition, the composition of the surface of laser-metallized ceramics was studied using energy-dispersive x-ray spectroscopy. As a result, it was shown that the resistance is inversely proportional to the square root of the pulse duration, the thermal diffusion length was estimated as <italic toggle=\"yes\">l<sub>T</sub>\u0000</italic> = 8.2 <italic toggle=\"yes\">μ</italic>m for 200 ns and <italic toggle=\"yes\">l<sub>T</sub>\u0000</italic> = 1.2 <italic toggle=\"yes\">μ</italic>m for 4 ns, and the presence of optimal values of pulse overlap <italic toggle=\"yes\">Oy</italic> (scanning direction) equal to 50% and pulse overlap <italic toggle=\"yes\">Ox</italic> (step direction) equal to 96% and 99.7% for pulse durations of 200 and 4 ns, respectively, was determined. The choice of optimal pulse overlaps with the highest laser fluence allowed us to obtain the minimum resistance value with maximum performance.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140615209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-04-10DOI: 10.1088/1612-202x/ad3a55
N A M Muhammad, N A Awang, H Basri, N U H H Zalkepali, M I Supaat
This study presents a novel structure saturable absorber (SSA) based on spider silk for wavelength tunable Q-switched erbium-doped fiber laser (EDFL) operation from S to L bands. The nonlinear optical absorption of spider silk was measured, showing a high modulation depth of 64.92%, a low saturation intensity of 0.03 MW cm−2, and a non-saturable loss of 24%. By adjusting the polarization controller, a wavelength tunable Q-switched EDFL was achieved, with a tuning range of 64 nm from 1522 nm to 1586 nm. The Q-switched pulses had a repetition rate varying from 20.62 kHz to 6.57 kHz and a pulse width ranging from 14.02 μs to 26.30 μs, corresponding to an output power from −11.31 dBm to −9.02 dBm at the maximum pump power of 151.40 mW. The proposed SSA using spider silk offers a low-cost, eco-friendly, and high-performance solution for wide wavelength tunable Q-switched EDFL applications in optical testing, fiber communication, optical fiber sensing, and ultrafast lasers.
{"title":"Biological material spider silk by direct incorporation onto fiber ferrule for wavelength tunable Q-switched application","authors":"N A M Muhammad, N A Awang, H Basri, N U H H Zalkepali, M I Supaat","doi":"10.1088/1612-202x/ad3a55","DOIUrl":"https://doi.org/10.1088/1612-202x/ad3a55","url":null,"abstract":"This study presents a novel structure saturable absorber (SSA) based on spider silk for wavelength tunable Q-switched erbium-doped fiber laser (EDFL) operation from S to L bands. The nonlinear optical absorption of spider silk was measured, showing a high modulation depth of 64.92%, a low saturation intensity of 0.03 MW cm<sup>−2</sup>, and a non-saturable loss of 24%. By adjusting the polarization controller, a wavelength tunable Q-switched EDFL was achieved, with a tuning range of 64 nm from 1522 nm to 1586 nm. The Q-switched pulses had a repetition rate varying from 20.62 kHz to 6.57 kHz and a pulse width ranging from 14.02 <italic toggle=\"yes\">μ</italic>s to 26.30 <italic toggle=\"yes\">μ</italic>s, corresponding to an output power from −11.31 dBm to −9.02 dBm at the maximum pump power of 151.40 mW. The proposed SSA using spider silk offers a low-cost, eco-friendly, and high-performance solution for wide wavelength tunable Q-switched EDFL applications in optical testing, fiber communication, optical fiber sensing, and ultrafast lasers.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140615187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-04-10DOI: 10.1088/1612-202x/ad3a54
Li-Hua Gong, Mao-Long Li, Hao Cao, Bing Wang
Based on Bell states, a new semi-quantum private comparison protocol is proposed that enables two classical users to securely compare the equality of their private information with the aid of a semi-honest third party. Different from the existing semi-quantum private comparison protocols, the two classical participants in the presented protocol do not need to measure and prepare any quantum state, which not only reduces the consumption of quantum devices, but also greatly improves the feasibility of the protocol. Performing different unitary operations on the received particles, classical users can securely compare their secret information. Besides, the devised protocol has higher qubit efficiency than the other similar counterparts, since participants can compare a two-bit privacy each time with one qubit. Meanwhile, after completing the comparison process, all Bell states could be reused since they still retain the corresponding entanglement property, which greatly facilitates the recycle of quantum resources. Security analyses indicate that the designed scheme is secure against external attack and internal attack. Moreover, the operations involved in our scheme are simulated on the IBM Quantum Experience to demonstrate the effectiveness and security of our scheme.
基于贝尔态，提出了一种新的半量子私密比对协议，使两个经典用户能够在半诚实第三方的帮助下安全地比对其私密信息的相等性。与现有的半量子私密比对协议不同，本协议中的两个经典参与者无需测量和准备任何量子态，这不仅减少了量子设备的消耗，还大大提高了协议的可行性。对接收到的粒子进行不同的单元操作，经典用户就可以安全地比较他们的秘密信息。此外，与其他类似协议相比，所设计的协议具有更高的量子比特效率，因为参与者每次只需使用一个量子比特就能比较两个比特的隐私信息。同时，在完成比对过程后，由于所有贝尔态仍保留相应的纠缠特性，因此可以重复使用，这极大地促进了量子资源的循环利用。安全性分析表明，所设计的方案可以抵御外部攻击和内部攻击。此外，我们还在 IBM 量子体验上模拟了我们方案中涉及的操作，以证明我们方案的有效性和安全性。
{"title":"Novel semi-quantum private comparison protocol with Bell states","authors":"Li-Hua Gong, Mao-Long Li, Hao Cao, Bing Wang","doi":"10.1088/1612-202x/ad3a54","DOIUrl":"https://doi.org/10.1088/1612-202x/ad3a54","url":null,"abstract":"Based on Bell states, a new semi-quantum private comparison protocol is proposed that enables two classical users to securely compare the equality of their private information with the aid of a semi-honest third party. Different from the existing semi-quantum private comparison protocols, the two classical participants in the presented protocol do not need to measure and prepare any quantum state, which not only reduces the consumption of quantum devices, but also greatly improves the feasibility of the protocol. Performing different unitary operations on the received particles, classical users can securely compare their secret information. Besides, the devised protocol has higher qubit efficiency than the other similar counterparts, since participants can compare a two-bit privacy each time with one qubit. Meanwhile, after completing the comparison process, all Bell states could be reused since they still retain the corresponding entanglement property, which greatly facilitates the recycle of quantum resources. Security analyses indicate that the designed scheme is secure against external attack and internal attack. Moreover, the operations involved in our scheme are simulated on the IBM Quantum Experience to demonstrate the effectiveness and security of our scheme.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140615204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-04-10DOI: 10.1088/1612-202x/ad3a57
Kuan-Yuan Chang, Jia-Ming Liu
We experimentally and numerically demonstrate that noise-like pulses (NLPs) can be generated by pumping well-defined pulses (WDPs) into an optical fiber amplifier at a wavelength in the region of negative group velocity dispersion. Through investigating the evolution of the optical pulses, it is realized that the output pulses consist of NLPs at the pump wavelength and split solitons at Stokes wavelengths, due to intrapulse Raman scattering followed by the process of soliton fission. Such process of pulse breakup results in the generation of sub-pulses that have peak powers much higher than the unbroken WDPs have, enabling WDPs to strongly induce nonlinear effects. This finding resolves the discrepancy between the experiment and simulation results of supercontinuum generation by using picosecond WDPs in previous research.
{"title":"Noise-like pulse generation by amplified well-defined pulse in an optical fiber with negative group velocity dispersion","authors":"Kuan-Yuan Chang, Jia-Ming Liu","doi":"10.1088/1612-202x/ad3a57","DOIUrl":"https://doi.org/10.1088/1612-202x/ad3a57","url":null,"abstract":"We experimentally and numerically demonstrate that noise-like pulses (NLPs) can be generated by pumping well-defined pulses (WDPs) into an optical fiber amplifier at a wavelength in the region of negative group velocity dispersion. Through investigating the evolution of the optical pulses, it is realized that the output pulses consist of NLPs at the pump wavelength and split solitons at Stokes wavelengths, due to intrapulse Raman scattering followed by the process of soliton fission. Such process of pulse breakup results in the generation of sub-pulses that have peak powers much higher than the unbroken WDPs have, enabling WDPs to strongly induce nonlinear effects. This finding resolves the discrepancy between the experiment and simulation results of supercontinuum generation by using picosecond WDPs in previous research.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140617820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-04-10DOI: 10.1088/1612-202x/ad3a53
Junjie Wang, Hongye Xu, Xinlei Ge
By solving a two-dimensional, time-dependent Schrödinger equation, we investigate high-order harmonic generation for the H2+ molecular ion in orthogonally polarized two-color laser pulses. We find that harmonic generation depends on the frequency ratio n=ωyωx. When the wavelength is 800 nm and n = 1.2, the harmonic plateau becomes smoother, and the quantum orbital interference decreases. We change the fundamental wavelength and find that the harmonic spectrum exhibits a supercontinuum structure, and the quantum orbital is controllable. When the wavelength is 1600 nm and 2000 nm, and n = 1.2, we gain a deeper understanding of the physical process of harmonics. We have provided the time-frequency distribution and the probability density of an electron wave packet picture. Next, we analyzed the impact of the carrier-envelope phase on harmonics, and we combined Lissajous figures to continue our analysis. The research results find that when the carrier-envelope phase is 0, 0.5π, π, and 1.5π, the harmonic intensity becomes higher, and all exhibit a supercontinuum structure. We chose certain orders of harmonics, and isolated attosecond pulses can be synthesized.
{"title":"Control of quantum paths in harmonic generation through orthogonal fields specific frequency ratios","authors":"Junjie Wang, Hongye Xu, Xinlei Ge","doi":"10.1088/1612-202x/ad3a53","DOIUrl":"https://doi.org/10.1088/1612-202x/ad3a53","url":null,"abstract":"By solving a two-dimensional, time-dependent Schrödinger equation, we investigate high-order harmonic generation for the <inline-formula>\u0000<tex-math><?CDATA $ H_2^+ $?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:msubsup><mml:mi>H</mml:mi><mml:mn>2</mml:mn><mml:mo>+</mml:mo></mml:msubsup></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"lplad3a53ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> molecular ion in orthogonally polarized two-color laser pulses. We find that harmonic generation depends on the frequency ratio <inline-formula>\u0000<tex-math><?CDATA $ n = frac{omega_y}{omega_x} $?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:mi>n</mml:mi><mml:mo>=</mml:mo><mml:mfrac><mml:msub><mml:mi>ω</mml:mi><mml:mi>y</mml:mi></mml:msub><mml:msub><mml:mi>ω</mml:mi><mml:mi>x</mml:mi></mml:msub></mml:mfrac></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"lplad3a53ieqn2.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>. When the wavelength is 800 nm and <italic toggle=\"yes\">n</italic> = 1.2, the harmonic plateau becomes smoother, and the quantum orbital interference decreases. We change the fundamental wavelength and find that the harmonic spectrum exhibits a supercontinuum structure, and the quantum orbital is controllable. When the wavelength is 1600 nm and 2000 nm, and <italic toggle=\"yes\">n</italic> = 1.2, we gain a deeper understanding of the physical process of harmonics. We have provided the time-frequency distribution and the probability density of an electron wave packet picture. Next, we analyzed the impact of the carrier-envelope phase on harmonics, and we combined Lissajous figures to continue our analysis. The research results find that when the carrier-envelope phase is 0, 0.5<italic toggle=\"yes\">π</italic>, <italic toggle=\"yes\">π</italic>, and 1.5<italic toggle=\"yes\">π</italic>, the harmonic intensity becomes higher, and all exhibit a supercontinuum structure. We chose certain orders of harmonics, and isolated attosecond pulses can be synthesized.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140615421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-04-04DOI: 10.1088/1612-202x/ad3817
Meng-Ya Dong, Su-Juan Zhang, Chen-Ming Bai, Lu Liu
In recent years, researchers focused their attention on the construction of nonlocal product states in multipartite quantum systems. This paper proposes a novel partitioning method for multipartite quantum systems, aiming to improve the operation efficiency. Firstly, we divide 2n subsystems into n parts two by two and implement orthogonality-preserving local measurement on the partitioned composite systems. Subsequently, based on the partitioning mode, nonlocal orthogonal product states in (C3)⊗6 and (C4)⊗6 are given. Finally, we construct nonlocal orthogonal product states in (Cd)⊗2n and discuss the cases where d is odd and even. Our results demonstrate the phenomenon of nonlocality without entanglement in a 2n-partite system.
近年来，研究人员将注意力集中在多方量子系统中非局域积态的构建上。本文提出了一种新颖的多方量子系统划分方法，旨在提高运行效率。首先，我们将 2n 个子系统两两分割成 n 个部分，并在分割后的复合系统上实现正交保全局部测量。然后，根据分割模式，给出 (C3)⊗6 和 (C4)⊗6 中的非局部正交积状态。最后，我们构建了 (Cd)⊗2n 中的非局部正交积状态，并讨论了 d 为奇数和偶数的情况。我们的结果证明了在 2n 对偶系统中没有纠缠的非局域现象。
{"title":"Quantum nonlocality without entanglement in a 2n-partite system","authors":"Meng-Ya Dong, Su-Juan Zhang, Chen-Ming Bai, Lu Liu","doi":"10.1088/1612-202x/ad3817","DOIUrl":"https://doi.org/10.1088/1612-202x/ad3817","url":null,"abstract":"In recent years, researchers focused their attention on the construction of nonlocal product states in multipartite quantum systems. This paper proposes a novel partitioning method for multipartite quantum systems, aiming to improve the operation efficiency. Firstly, we divide 2<italic toggle=\"yes\">n</italic> subsystems into <italic toggle=\"yes\">n</italic> parts two by two and implement orthogonality-preserving local measurement on the partitioned composite systems. Subsequently, based on the partitioning mode, nonlocal orthogonal product states in <inline-formula>\u0000<tex-math><?CDATA $ (mathbb{C}^{3})^{otimes 6 }$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:mo stretchy=\"false\">(</mml:mo><mml:msup><mml:mrow><mml:mi mathvariant=\"double-struck\">C</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msup><mml:msup><mml:mo stretchy=\"false\">)</mml:mo><mml:mrow><mml:mo>⊗</mml:mo><mml:mn>6</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"lplad3817ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> and <inline-formula>\u0000<tex-math><?CDATA $(mathbb{C}^{4})^{otimes 6 }$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:mo stretchy=\"false\">(</mml:mo><mml:msup><mml:mrow><mml:mi mathvariant=\"double-struck\">C</mml:mi></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msup><mml:msup><mml:mo stretchy=\"false\">)</mml:mo><mml:mrow><mml:mo>⊗</mml:mo><mml:mn>6</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"lplad3817ieqn2.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> are given. Finally, we construct nonlocal orthogonal product states in <inline-formula>\u0000<tex-math><?CDATA $(mathbb{C}^{d})^{otimes 2n}$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:mo stretchy=\"false\">(</mml:mo><mml:msup><mml:mrow><mml:mi mathvariant=\"double-struck\">C</mml:mi></mml:mrow><mml:mrow><mml:mi>d</mml:mi></mml:mrow></mml:msup><mml:msup><mml:mo stretchy=\"false\">)</mml:mo><mml:mrow><mml:mo>⊗</mml:mo><mml:mn>2</mml:mn><mml:mi>n</mml:mi></mml:mrow></mml:msup></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"lplad3817ieqn3.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> and discuss the cases where <italic toggle=\"yes\">d</italic> is odd and even. Our results demonstrate the phenomenon of nonlocality without entanglement in a 2<italic toggle=\"yes\">n</italic>-partite system.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140595640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-04-03DOI: 10.1088/1612-202x/ad3815
Pengwei Zhou, Jiamin Zhou, Yangfan Lv
In the design of the Computed Tomographic Imaging Spectrometer (CTIS), in order to optimize the holographic grating and achieve better design performance, this paper proposes a novel optimization algorithm based on the Gerchberg–Saxton (GS) iterative algorithm. This algorithm combines the weighted GS algorithm with the interior point method (IPM). By introducing weight factors for phase and amplitude in the optimization process of the GS algorithm, and incorporating the actual diffraction characteristics of the holographic grating obtained from the Computer Simulation Technology Studio Suite into the IPM optimization process, a more optimized design performance is achieved. Using this algorithm, a metasurface holographic grating is designed, which can transform the input parallel light into a dispersion image of 25 diffraction orders on a focal plane array. The transmission efficiency exceeds 72%, and the root mean square error between different diffraction orders is less than 0.1. Among them, the optimization time is shortened by approximately 70% due to a significant reduction in the number of independent variables through symmetry. Through comparison, this method can further improve the uniformity of energy distribution based on the original algorithm, avoid being trapped in local extreme values, and thus enhance the overall design quality of the CTIS.
{"title":"Metasurface CGH optimization for CTIS based on interior point method","authors":"Pengwei Zhou, Jiamin Zhou, Yangfan Lv","doi":"10.1088/1612-202x/ad3815","DOIUrl":"https://doi.org/10.1088/1612-202x/ad3815","url":null,"abstract":"In the design of the Computed Tomographic Imaging Spectrometer (CTIS), in order to optimize the holographic grating and achieve better design performance, this paper proposes a novel optimization algorithm based on the Gerchberg–Saxton (GS) iterative algorithm. This algorithm combines the weighted GS algorithm with the interior point method (IPM). By introducing weight factors for phase and amplitude in the optimization process of the GS algorithm, and incorporating the actual diffraction characteristics of the holographic grating obtained from the Computer Simulation Technology Studio Suite into the IPM optimization process, a more optimized design performance is achieved. Using this algorithm, a metasurface holographic grating is designed, which can transform the input parallel light into a dispersion image of 25 diffraction orders on a focal plane array. The transmission efficiency exceeds 72%, and the root mean square error between different diffraction orders is less than 0.1. Among them, the optimization time is shortened by approximately 70% due to a significant reduction in the number of independent variables through symmetry. Through comparison, this method can further improve the uniformity of energy distribution based on the original algorithm, avoid being trapped in local extreme values, and thus enhance the overall design quality of the CTIS.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140595764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-04-03DOI: 10.1088/1612-202x/ad3627
Fan-Zhen Kong, Jun-Long Zhao
We studied the entangling power of two pure global noises, i.e. amplitude damping noise and classic noise. The entangling power of the two-qubit amplitude damping global noise periodically oscillates with time. Additionally, the entangling power of two-qubit global classical noise increases exponentially with time. The maximum entangling power of both of them exceeds that of the perfect entanglers. Based on this, we propose the conditions for generating a maximally entangled state with global noise acting on a two-qubit separable state. Only if the two-qubit composite system, which is initially in one of those product states: 12(|0⟩±|1⟩)⊗12(|0⟩±|1⟩), |10⟩ and |01⟩ suffers an amplitude damping global noise, can we prepare this system in the maximally entangled state by appropriately controlling the evolution time of amplitude damping. Finally, we investigate the disentanglement of the maximum entangled Bell state using these two types of global noise. The two global noises cannot completely disentangle the Bell states Φ±
{"title":"Generating a maximally entangled state via a pure global noise environment","authors":"Fan-Zhen Kong, Jun-Long Zhao","doi":"10.1088/1612-202x/ad3627","DOIUrl":"https://doi.org/10.1088/1612-202x/ad3627","url":null,"abstract":"We studied the entangling power of two pure global noises, i.e. amplitude damping noise and classic noise. The entangling power of the two-qubit amplitude damping global noise periodically oscillates with time. Additionally, the entangling power of two-qubit global classical noise increases exponentially with time. The maximum entangling power of both of them exceeds that of the perfect entanglers. Based on this, we propose the conditions for generating a maximally entangled state with global noise acting on a two-qubit separable state. Only if the two-qubit composite system, which is initially in one of those product states: <inline-formula>\u0000<tex-math><?CDATA $frac{1}{sqrt{2}}(|0rangle pm |1rangle)otimes frac{1}{sqrt{2}}(|0rangle pm |1rangle)$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:mfrac><mml:mn>1</mml:mn><mml:msqrt><mml:mn>2</mml:mn></mml:msqrt></mml:mfrac><mml:mo stretchy=\"false\">(</mml:mo><mml:mrow><mml:mo stretchy=\"false\">|</mml:mo></mml:mrow><mml:mn>0</mml:mn><mml:mo fence=\"false\" stretchy=\"false\">⟩</mml:mo><mml:mo>±</mml:mo><mml:mrow><mml:mo stretchy=\"false\">|</mml:mo></mml:mrow><mml:mn>1</mml:mn><mml:mo fence=\"false\" stretchy=\"false\">⟩</mml:mo><mml:mo stretchy=\"false\">)</mml:mo><mml:mo>⊗</mml:mo><mml:mfrac><mml:mn>1</mml:mn><mml:msqrt><mml:mn>2</mml:mn></mml:msqrt></mml:mfrac><mml:mo stretchy=\"false\">(</mml:mo><mml:mrow><mml:mo stretchy=\"false\">|</mml:mo></mml:mrow><mml:mn>0</mml:mn><mml:mo fence=\"false\" stretchy=\"false\">⟩</mml:mo><mml:mo>±</mml:mo><mml:mrow><mml:mo stretchy=\"false\">|</mml:mo></mml:mrow><mml:mn>1</mml:mn><mml:mo fence=\"false\" stretchy=\"false\">⟩</mml:mo><mml:mo stretchy=\"false\">)</mml:mo></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"lplad3627ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>, <inline-formula>\u0000<tex-math><?CDATA $|10rangle$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:mo stretchy=\"false\">|</mml:mo><mml:mn>10</mml:mn><mml:mo fence=\"false\" stretchy=\"false\">⟩</mml:mo></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"lplad3627ieqn2.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> and <inline-formula>\u0000<tex-math><?CDATA $|01rangle$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:mo stretchy=\"false\">|</mml:mo><mml:mn>01</mml:mn><mml:mo fence=\"false\" stretchy=\"false\">⟩</mml:mo></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"lplad3627ieqn3.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> suffers an amplitude damping global noise, can we prepare this system in the maximally entangled state by appropriately controlling the evolution time of amplitude damping. Finally, we investigate the disentanglement of the maximum entangled Bell state using these two types of global noise. The two global noises cannot completely disentangle the Bell states <inline-formula>\u0000<tex-math><?CDATA $Phi^{pm}$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:msup><mml:mi mathvariant=\"normal\">Φ</mml:mi><mml:mrow><mml:mo>±</mml:mo></mml:mrow></mml:msup>","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140595758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-04-02DOI: 10.1088/1612-202x/ad3621
Chengji Liu, Yu Chao, Lu Wang, Changhua Zhu, Qingshan Li
Recently, we proposed a continuous variable quantum key distribution (CVQKD) scheme based on simultaneous quantum and classical communication (SQCC) in the terahertz (THz) band. It performs classical modulation and quantum Gaussian modulation at the same coherent pulse at the sending end, and an amplifier is used to amplify and demultiplex the signal at the receiving end. However, the previous study set parameters based on prior knowledge which has significant limitations, and as the previous study showed, parameter selection is a crucial task that directly affects the performance of the system. In this paper, we use the genetic algorithm to optimize the parameter selection, and how the different conditions influence the optimal value of parameters is also analyzed. The simulation results show that the parameter optimized with the algorithm can make the scheme achieve a higher secret key rate which greatly improves the applicability of the SQCC scheme in the THz band. This work demonstrates the effectiveness of the scheme to construct wireless quantum communication networks.
{"title":"Parameter optimization of SQCC-CVQKD based on genetic algorithm in the terahertz band","authors":"Chengji Liu, Yu Chao, Lu Wang, Changhua Zhu, Qingshan Li","doi":"10.1088/1612-202x/ad3621","DOIUrl":"https://doi.org/10.1088/1612-202x/ad3621","url":null,"abstract":"Recently, we proposed a continuous variable quantum key distribution (CVQKD) scheme based on simultaneous quantum and classical communication (SQCC) in the terahertz (THz) band. It performs classical modulation and quantum Gaussian modulation at the same coherent pulse at the sending end, and an amplifier is used to amplify and demultiplex the signal at the receiving end. However, the previous study set parameters based on prior knowledge which has significant limitations, and as the previous study showed, parameter selection is a crucial task that directly affects the performance of the system. In this paper, we use the genetic algorithm to optimize the parameter selection, and how the different conditions influence the optimal value of parameters is also analyzed. The simulation results show that the parameter optimized with the algorithm can make the scheme achieve a higher secret key rate which greatly improves the applicability of the SQCC scheme in the THz band. This work demonstrates the effectiveness of the scheme to construct wireless quantum communication networks.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140595637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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