Optics express最新文献

{"title":"Spatiotemporal vector optimization algorithm for arbitrary optical multi-beams generation with high energy utilization efficiency.","authors":"Rusheng Zhuo, Kang Liu, Yanwei Huang, Xiaoxian He, Zixuan Wang, Ergu Fu, Fu Tang, Jingtao Bai, Kexuan Wang, Liang Wu, Feng Liang, Pinghe Wang, Qinggui Tan, Xiangru Wang","doi":"10.1364/OE.542628","DOIUrl":"https://doi.org/10.1364/OE.542628","url":null,"abstract":"<p><p>For the application scenario of multi-user, high-bandwidth laser communication in satellite internet, this paper proposes a spatiotemporal vector optimization algorithm to achieve high energy utilization in arbitrary multi-beam generation using a liquid crystal optical phased array antenna. The core components of this method involve optimizing phase offsets and power coefficients through iterative processes to achieve precise beam shaping and efficient energy distribution among multiple beams. This approach overcomes the single-link limitation of traditional laser terminals and resolves challenges such as low radiation efficiency and substantial power loss in multi-beam generation systems utilizing passive phased array antennas. When tasked with generating 90 beams with arbitrary intensity and elevation angles, the proposed method achieved a diffraction efficiency exceeding 80%, a system power loss of less than -1.28 <i>dB</i>, and an average improvement in laser radiation efficiency of 12.33 <i>dB</i>. This approach significantly improves the communication signal-to-noise ratio while potentially reducing the number of satellite network nodes, conserving power, and extending the operational lifespan of satellites within the communication network.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 2","pages":"2576-2592"},"PeriodicalIF":3.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143060214","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}

{"title":"Spectral radiance calibration method for spectroradiometers based on diffraction aberration factors correction.","authors":"Yao Li, Yiwen Li, Ge Chen, Hui Ma, Puyousen Zhang, Jingang Zhao, Wenqi Ma, Chunyu Liu","doi":"10.1364/OE.549749","DOIUrl":"https://doi.org/10.1364/OE.549749","url":null,"abstract":"<p><p>A spectroradiometer serves as a powerful instrument for measuring the spectral radiance of a target. The spectral radiance calibration function determines the measurement accuracy of the spectroradiometer. However, the general full-field calibration method results in higher spectral radiance values when dealing with targets that only partially fill the field of view (FOV). This error arises from the failure to account for the diffraction aberration factor, which represents the loss in response voltages on the spectroradiometer. To address this issue, we propose a spectral radiance calibration method based on diffraction aberration factors correction, which change with the FOV occupied by target. To obtain these factors, we have established a system where an infinite point source is conducted using a collimator and a blackbody incident on a pinhole. Different FOVs are achieved by adjusting the incident angle of the infinite point source. The experiment calibrated these diffraction aberration factors and demonstrates their spectral independence. Furthermore, the results highlight the effectiveness of the proposed method, even when the measured target is not circular and does not fully occupy the FOV.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 2","pages":"3400-3413"},"PeriodicalIF":3.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143060216","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}

{"title":"Broadband photothermal spectroscopy with a mid-infrared quantum cascade laser frequency comb.","authors":"Baichuan Huang, Grzegorz Gomółka, Tommi Mikkonen, Gerard Wysocki","doi":"10.1364/OE.544229","DOIUrl":"https://doi.org/10.1364/OE.544229","url":null,"abstract":"<p><p>We demonstrate a broadband photothermal spectroscopy in the mid-infrared region using a quantum cascade laser frequency comb operating between ∼7.7 and ∼8.2 µm covering a frequency range of ∼70 cm^-1. The photothermal spectroscopy technique employs a Mach-Zehnder interferometer operating in a pump-probe configuration, where the mid-infrared pump beam is modulated by a Fourier transform spectrometer. A 76-m Herriott-type multipass cell is used for signal enhancement. As a proof-of-concept, we have measured the photothermal spectra of nitrous oxide that show good agreement with the HITRAN database. A minimum detection limit of 83 ppb of nitrous oxide in nitrogen is estimated from a broadband photothermal spectrum with 9.9 GHz spectral point spacing and acquired over 78 minutes. This detection scheme also provides over three orders of magnitude of photothermal signal linearity with gas concentration. This spectroscopic method combines the functionality of high sensitivity and background-free detection of photothermal spectroscopy as well as broadband mid-infrared operation of quantum cascade laser frequency comb, which could find applications in trace gas sensing systems that benefit from these features.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 2","pages":"2126-2137"},"PeriodicalIF":3.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143060224","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}

{"title":"Compact module for video-rate image mosaics in two-photon microscopy.","authors":"Sean Quirin","doi":"10.1364/OE.544906","DOIUrl":"https://doi.org/10.1364/OE.544906","url":null,"abstract":"<p><p>Biological applications using multiphoton microscopy increasingly seek a larger field of view while maintaining sufficient temporal sampling to observe dynamic biological processes. Multiphoton imaging also requires high numerical aperture microscope objectives to realize efficient non-linear excitation and collection of fluorescence. This combination of low-magnification and high-numerical aperture poses a challenge for system design. To address this, the use of a liquid crystal polarization grating stack is proposed here to temporally sequence through multiple fields of view. This solution pans the native field of view with minimal latency and zero inertial movement of either the microscope or biological sample. Implemented as a simple add-on unit to existing multi-photon microscopes, this device increases the total field size by 4x, covering up to 7.6mm². Performance constraints and functional demonstration of imaging neural activity are presented.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 2","pages":"1647-1659"},"PeriodicalIF":3.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143060237","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}

{"title":"Programmable beam steering and quasi-continuous phase shift on a 2-bit terahertz coding metasurface with HEMT-switched multimodal modulation.","authors":"Tianyang Song, Feng Lan, Luyang Wang, Hongxin Zeng, Shixiong Liang, Munan Yang, Dongfang Shen, Wenxin Liu, Pinaki Mazumder, Yaxin Zhang, Ziqiang Yang","doi":"10.1364/OE.544013","DOIUrl":"https://doi.org/10.1364/OE.544013","url":null,"abstract":"<p><p>Terahertz reconfigurable intelligent surfaces (RIS) stand out from conventional phased arrays thanks to their unique electromagnetic properties and intelligent interconnect paradigms. They are a vital technology for terahertz wireless communication and radar detection systems. Compared with 1-bit coding metasurfaces, 2-bit coding metasurfaces offer significant advantages such as single beam steering and reduced quantization errors. Electrically controlled switchable coding metasurfaces have been restricted by the switch performance and integration technology, limiting reported devices to 1-bit coding. Additionally, metasurfaces that offer quasi-continuous phase modulation across a 2π range have garnered extensive attention for their higher phase shift precision and regulation freedom. This paper proposes a 2-bit multimodal THz quasi-continuous phase shift coding metasurface based on asymmetrically configured high electron mobility transistor (HEMT)-dipoles. The meta-device consists of two asymmetrically combined HEMT-dipole resonant structures, wherein the versatile density variations of two-dimensional electron gas (2DEG) introduce subtly local-field modulation under different external voltage combinations, rendering the quasi-continuous phase shift of 0° to 350° at 0.376 THz with a minimum incremental step of 6°. Moreover, selecting optimal 2-bit coding states within the quasi-continuous phase shift loop constructed different array phase gradients based on Snell's law, enabling real-time beam steering from 21° to 48° within the 0.365-0.385 THz frequency range. The simulation results align closely with the experimental findings, marking the first achievement of real-time programmable phase shift control and 2-bit beam steering using electrically controlled switches in the terahertz domain. This research provides a practical approach for real-time quasi-optical continuous phase modulation control and programmable single-beam electronic steering, with promising applications in terahertz wireless communication, radar detecting, and computational imaging, among other fields.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 2","pages":"2980-2994"},"PeriodicalIF":3.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143060258","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}

{"title":"Robust terahertz on-chip topological pathway with single-mode and linear dispersion.","authors":"Xusheng He, Lan Wang, Zitong Huang, Chaoming Xia, Xin Gao, Ziqiang Yang, Yaxin Zhang","doi":"10.1364/OE.545620","DOIUrl":"https://doi.org/10.1364/OE.545620","url":null,"abstract":"<p><p>Terahertz on-chip pathway is crucial for next-generation wireless communication, terahertz integrated circuits, and high-speed chip interconnections, yet its development is impeded by issues like channel crosstalk and disordered scattering. In this study, we propose and experimentally demonstrate a terahertz on-chip topological pathway that exhibits exceptional transmission robustness, unaffected by structural curvature. The pathway is constructed using a subwavelength structure that combines the benefits of topological properties, such as broadband single-mode transmission and linear dispersion, with the field localization effects of periodic metal structures. By integrating topological protection into radio frequency circuits through metal microstructures, the device maintains efficient terahertz wave transmission even in the presence of scattering or structural defects while minimizing signal interference. These findings hold significant potential for applications in radio frequency device transmission and chip interconnection, particularly within the terahertz frequency range.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 2","pages":"3350-3360"},"PeriodicalIF":3.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143060281","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}

{"title":"Superfluorescence and nonlinear optical response of CH₃NH₃PbBr₃-based mesostructures: applications to amplified spontaneous emission and ultrafast lasers.","authors":"Qianwen Wang, Jingjing Yang, Zijun Zhan, Huiling Kou, Zhengzheng Liu, Yubo Wang, Xueyao Liu, Siyu Dong, Tuo Li, Xiaofeng Zou, Wenbin Zhou, Qiuting Yan, Juan Du, Dengwang Li, Chen Cheng, Shuhao Si","doi":"10.1364/OE.543117","DOIUrl":"https://doi.org/10.1364/OE.543117","url":null,"abstract":"<p><p>Metal halide perovskites have unique luminescent properties that make them an attractive alternative for high quality light-emitting devices. However, the poor stability of perovskites with many defects and the long cycle time for the preparation of perovskite nanocomposites have hindered their production and application. Here, we prepared the perovskite mesostructures by embedding MAPbBr₃ nanocrystals in the mesopores on the surface of silica nanospheres and mixing the nanospheres with silver nanowires and poly(methyl methacrylate) (PMMA), and further explored their optical properties. The perovskite mesostructures exhibited superfluorescence (SF) under 785 nm laser excitation and the decay time was as short as 0.59 ps using a double exponential decay fit. The optical nonlinearity of these perovskite mesostructures under two-photon excitation was investigated by the Z-scanning technique. The samples exhibited both two-photon absorption (TPA) and saturation absorption (SA) with nonlinear absorption coefficients <i>β</i> ranging approximately 0.15 to 0.89 cm/GW corresponding to the TPA, and a saturation intensity of about 0.026 GW/cm² was determined. In addition, the quality of the perovskite mesostructures was shown to be significantly improved, including an increase in radiative efficiency and an extension of the optical gain lifetime. The samples were excited by a two-photon femtosecond laser pump at room temperature and atmospheric pressure, and the laser peak appeared at 540.1 nm with a low amplified spontaneous emission (ASE) threshold of 0.52 mJ/cm². Moreover, the perovskite mesostructures have been added to the fiber laser system as a saturable absorber, and the Q-switched pulse is generated at the wavelength of 1.5 µm. Our work effectively demonstrates that perovskite mesostructured materials can be functionalized for photonic devices, paving the way for further exploration of complex, functional and practical perovskite.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 2","pages":"1625-1635"},"PeriodicalIF":3.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143060312","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}

{"title":"THz-induced gas alignment in dispersionless field enhancing waveguides.","authors":"David Rohrbach, Lukas Beéry, Seyyed Jabbar Mousavi, Hans-Martin Frey, Bong Joo Kang, Elnaz Zyaee, Zhinan Zeng, Thomas Feurer","doi":"10.1364/OE.543482","DOIUrl":"https://doi.org/10.1364/OE.543482","url":null,"abstract":"<p><p>We demonstrate a versatile THz waveguide platform for tailored THz-induced orientation and alignment of gas molecules. The underlying waveguide structure is dispersionless, with a refractive index close to one, and enhances the electric as well as the magnetic field up to a factor of five. These properties increase the detected transient birefringence signal by more than an order of magnitude compared to conventional THz free space focusing. We apply this new platform to align two molecular systems and compare the results to theory. Furthermore, we present THz pulse shaping for coherently controlled alignment.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 2","pages":"3315-3324"},"PeriodicalIF":3.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143060325","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}

{"title":"Two-dimensional integrated optical phased array with high fill-factor antennas.","authors":"Warren Kut King Kan, Sylvain Guerber, Stéphanie Garcia, Daivid Fowler, Natnicha Koompai, Daniele Melati, Carlos Alonso-Ramos","doi":"10.1364/OE.543258","DOIUrl":"https://doi.org/10.1364/OE.543258","url":null,"abstract":"<p><p>A silicon photonics optical phased array with a two-dimensional matrix of antennas is experimentally demonstrated in which the unitary antennas are optimized such that light can be emitted over a high fraction of the overall array surface. This design strategy can be used to obtain a low divergence emitted beam containing a significant fraction of the total emitted power, at the expense of a reduced beam steering range. This type of device can be suited to phase front correction in optical wireless communications systems.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 2","pages":"3554-3561"},"PeriodicalIF":3.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143060336","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}

{"title":"Optical tactile sensor based on a flexible optical fiber ring resonator for intelligent braille recognition.","authors":"Heng Wang, Lin Ma, Qin Nie, Xuehao Hu, Xiaoli Li, Rui Min, Zhuo Wang","doi":"10.1364/OE.546873","DOIUrl":"https://doi.org/10.1364/OE.546873","url":null,"abstract":"<p><p>Inspired by human skin, bionic tactile sensing is effectively promoting development and innovation in many fields with its flexible and efficient perception capabilities. Optical fiber, with its ability to perceive and transmit information and its flexible characteristics, is considered a promising solution in the field of tactile bionics. In this work, one optical fiber tactile sensing system based on a flexible PDMS-embedded optical fiber ring resonator (FRR) is designed for braille recognition, and the Pound-Drever-Hall (PDH) demodulation scheme is adopted to improve the detection sensitivity. Theoretical simulations and experimental verifications show that by adopting a bionic sliding approach and a Multilayer Perceptron Neural Network, a single FRR with a hardness gradient design can detect eight different tactile pressures in braille characters with an accuracy of 98.57%. Furthermore, after training and testing, the MLP-LSTM model classifies time series signals, thereby achieving completely accurate encoding of braille keywords and braille poems. The advantages of the optical fiber tactile sensing system in this study are that the high-quality factor FRR can detect subtle differences in braille dots, it is not affected by changes in optical power due to its relies on PDH frequency demodulation, and the application of machine learning algorithms can enhance the robustness to slight pressure errors and simplify the recognition process. This solution opens up what we believe is a new optical approach for bionic tactile perception and has important potential value in promoting human-computer interaction, smart medical care, and other fields.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 2","pages":"2512-2528"},"PeriodicalIF":3.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143059307","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}