Optics Communications最新文献

{"title":"Orthogonal HL states and extrema method for the polarization evaluation","authors":"M. Fernández-Guasti,&nbsp;J. Feliciano-Zenón","doi":"10.1016/j.optcom.2024.131343","DOIUrl":"10.1016/j.optcom.2024.131343","url":null,"abstract":"<div><div>Is it possible to quantitatively measure the polarization of light without a light meter? Since the Stokes parameters require four or six intensity measurements, the immediate reply would be negative. Surprisingly, the query can be answered in the affirmative. To this end, it is convenient to describe the polarization of light via orthogonal Heaviside Larmor (HL) elliptical polarization states. The parameters of an ellipse are in this way directly related to the wave coefficients. Thereafter, utilizing a modified null ellipsometry novel method, we show that it is possible to measure the Poincaré polarization sphere angles circumventing intensity measurements. The procedure involves setting a linear polarizer and a removable quarter waveplate at the intensity extrema, without requiring to take intensity readings unless the depolarized contribution needs to be assessed. To this end, only three simple steps need to be performed taking two angle readings from the rotation mount. It is also possible to use this extrema procedure recording four intensities in order to obtain the state of polarization of a source. In either case, the Stokes parameters are unneeded although they can be derived from the extrema measurements. This method could prove useful to measure space dependent polarizations in structured light. It may also provide a more economic measurement procedure in null ellipsometry.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"576 ","pages":"Article 131343"},"PeriodicalIF":2.2,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Sensitivity-enhanced temperature sensor with parallel dual fabry-perot interferometers structure based on harmonic Vernier effect","authors":"Cheng Zuo ,&nbsp;Kaiyang Wu ,&nbsp;Jiatong Luo ,&nbsp;Dong Guang ,&nbsp;Jun Zhu ,&nbsp;Xuqiang Wu ,&nbsp;Jinhui Shi ,&nbsp;Benli Yu","doi":"10.1016/j.optcom.2024.131363","DOIUrl":"10.1016/j.optcom.2024.131363","url":null,"abstract":"<div><div>A sensitivity-enhanced temperature sensor with a parallel dual Fabry-Perot interferometers (FPIs) structure based on the harmonic Vernier effect is proposed and experimentally demonstrated. The sensing FPI is fabricated by fusion splicing a multi-hundred-micron long polarization maintaining photonic crystal fiber (PMPCF) tip with a single mode fiber (SMF). The reference FPI is fabricated by inserting two SMFs into the ends of a single-pore capillary. The length of the air cavity in the reference FPI is controlled and optimized to create a harmonic Vernier effect, thereby achieving significant sensitization of the sensor sensitivity and modulation of the amplification factor. Experimental results show that the temperature sensitivity of the single sensing FPI is 11.9 p.m./°C from 40 °C to 400 °C, and the temperature sensitivities of the parallel dual FPIs based on the harmonic Vernier effect are −408.95 p.m./°C, −723.23 p.m./°C, and −1.93 nm/°C, respectively. The proposed sensor has a simple structure, high sensitivity, and excellent stability, making it have certain application prospects in high temperature measurement fields such as aerospace and metallurgy.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"576 ","pages":"Article 131363"},"PeriodicalIF":2.2,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"A robust program-controlled microcomb source","authors":"Sifei Chen ,&nbsp;Hongzhi Yang ,&nbsp;Suyi Zhao,&nbsp;Ruizhi Yi,&nbsp;Ziyue Zhang,&nbsp;Zhongyuan Fu,&nbsp;Yang Xie,&nbsp;Wei Huang,&nbsp;Lin Xiao","doi":"10.1016/j.optcom.2024.131354","DOIUrl":"10.1016/j.optcom.2024.131354","url":null,"abstract":"<div><div>Optical frequency combs generated by nonlinear effects in microcavities have played an important role in many fields due to their precise frequency characteristics. However, constrained by the strict requirement of the balance between the nonlinear effect and the dispersion and the thermal instability when reaching the soliton states, the current microcomb sources are mostly heavily reliant on manual tests and are environmentally sensitive. We present a compact FPGA-based microcomb source. Thresholds of the average and variance of the transmitted signal are determined from sampled spectrum and used for the distinguishment of the intra-cavity state. Generation of arbitrary optical state and self-recovery under external disturbance is achieved. Furthermore, feedback locking is applied to the laser frequency via the output power, which improves the immunity to temperature changes. The presented source shows great stability which can promote future applications of microcombs.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"576 ","pages":"Article 131354"},"PeriodicalIF":2.2,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Large angle and high uniform diffractive laser beam splitter with divergent spherical wave illumination","authors":"Churan Han,&nbsp;Qiaofeng Tan","doi":"10.1016/j.optcom.2024.131355","DOIUrl":"10.1016/j.optcom.2024.131355","url":null,"abstract":"<div><div>Splitting angle, generally limited by the feature size of diffractive optical element (DOE), is one of the significant metrics of the diffractive laser beam splitter. In this study, we realize large angle and high uniform split beams by using a divergent spherical wave front incidence. For designing this diffractive beam splitter, the Gerchberg-Saxton (GS) optimization algorithm which is known as a widely used method in DOE design is modified. Meanwhile, a negative feedback method is proposed to further improve the uniformity in experiment to compensate the incident wavefront distortion. Finally, a phase-only spatial light modulator (SLM) was used to test the feasibility and adaptiveness of our design strategy. In the experiment, we achieved several kinds of beam splitters and the uniformities are all better than 3.0% which the uniformity is measured by the peak-to-valley (PV) ratio.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"576 ","pages":"Article 131355"},"PeriodicalIF":2.2,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Underwater reflective single-pixel imaging based on parallel networks through strong scattering media under low sampling rates","authors":"Wei Feng,&nbsp;Yongcong Yi,&nbsp;Yi Wang,&nbsp;Zhen Zeng,&nbsp;Boya Xie","doi":"10.1016/j.optcom.2024.131353","DOIUrl":"10.1016/j.optcom.2024.131353","url":null,"abstract":"<div><div>Single-pixel imaging (SPI) boasts higher detection sensitivity and a broader detection bandwidth, and it exhibits significant advantages in extremely low-light conditions and underwater imaging involving scattering media. However, with the increase in the intensity of scattering media in underwater environments, the image reconstruction quality of SPI severely deteriorates. In this paper, an underwater reflective SPI system based on parallel networks is designed and built to achieve high-quality imaging in turbid waters at low sampling rates. The proposed network consists of an upper branch and a lower branch, and the upper branch consists of a multi-scale initial feature extraction network and a multi-scale feature transformation network to enhance the network's ability to learn high-frequency information, and the lower branch is mainly responsible for generating images. Additionally, a multi-scale structural similarity index measure and normalized mean square error are also designed as loss functions to better learn images features with varying sizes. Simulations and experiments demonstrate that the network is capable of reconstructing underwater objects at a 3.125% sampling rate and 90 NTU turbidity, and it indicates that the network has strong generalization abilities.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"576 ","pages":"Article 131353"},"PeriodicalIF":2.2,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Harmonics suppression in frequency domain for fringe projection profilometry with arbitrary phase shifts","authors":"Shuai Lin ,&nbsp;Jianli Zhu ,&nbsp;Hongwei Guo","doi":"10.1016/j.optcom.2024.131346","DOIUrl":"10.1016/j.optcom.2024.131346","url":null,"abstract":"<div><div>In phase-shifting fringe projection profilometry, nonlinearities of the used devices affect measurement accuracy by induing harmonics in fringe signals. The resulting errors are manifested as ripple artifacts in the measured phase maps. Especially when phase shifts are not uniform, the error artifacts have unpredictable profiles and complicated frequency components thus being not easy to eliminate. To solve this problem, this paper suggests a method for suppressing effects of fringe harmonics when using arbitrary phase shifts. For doing it, this paper derives the frequency transfer function that explicitly represents the response of the phase-shifting algorithm to each order of fringe harmonics, and then uses this function to deduce a method that allows one to estimate the coefficients of harmonics from spectrum of the calculated complex fringe pattern. By iteratively subtracting off the estimated harmonics from the calculated complex fringe pattern, fringe phases are calculated accurately. Simulation and experimental results demonstrate that this method significantly suppresses the influence of fringe harmonics on measurement results and, simultaneously, it preserves edges and details of the measured object from being blurred.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"576 ","pages":"Article 131346"},"PeriodicalIF":2.2,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"RECNN: Restoration and extraction of incomplete brillouin gain spectrum based on CNN framework combined with SVAE and attention mechanism","authors":"Han Shu,&nbsp;Huan Zheng,&nbsp;Yali Qin","doi":"10.1016/j.optcom.2024.131351","DOIUrl":"10.1016/j.optcom.2024.131351","url":null,"abstract":"<div><div>In this paper, we propose a novel method under convolutional neural network framework combined with a supervised variational autoencoder and an attention mechanism, named the Restoration and Extraction Convolutional Neural Network (RECNN), for the restoration and extraction of Incomplete Brillouin Gain Spectrum (IBGS). It is important to clarify that the IBGS discussed here does not encompass information around the Brillouin Frequency Shift (BFS). This omission complicates the task of reconstructing the original spectrum or determining the BFS value. The RECNN framework consists of two main components: Restoration Supervised Variational Autoencoder (RSVAE) with an attention module for IBGS restoration, and Residual Attention Convolutional Neural Network (RACNN) for BFS extraction. Different types of IBGS are discussed in detail. We define the K index to quantify the incompleteness of the IBGS and introduce the R-squared index to measure the restoration performance of RSVAE. Additionally, the Root Mean Square Error (RMSE) and uncertainty are used to evaluate the overall performance of RECNN. Both simulation and experimental results demonstrate that the R-squared index increases with increasing K and Signal-to-Noise Ratio (SNR), while both RMSE and uncertainty decrease with increasing K and SNR. In comparisons with various other methods including Linear Curve Fitting (LCF) and artificial neural networks, RECNN consistently outperforms them. Specifically, simulation results show that when K is 0.5 and SNR is 4 dB, the R-squared value for RSVAE reaches 0.82, significantly higher than the 0.31 achieved by LCF method. Experimental results indicate that for an SNR of 6.78 dB and K of 0.5, the RMSE and uncertainty of RECNN are 3.21 MHz and 2.68 MHz, respectively, representing reductions of 11.43 MHz and 11.17 MHz compared to LCF. It's noteworthy that the time consumption evaluation indicates that RECNN requires less than 7 ms to restore the complete BGS and obtain the BFS value. These results are consistently observed in both simulations and experimental studies, which bodes well for the future of extracting valuable latent information from outdated and corrupted data stored in databases of distributed fiber sensing applications.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"576 ","pages":"Article 131351"},"PeriodicalIF":2.2,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Multi-facial freeform monolith optics for astronomical and space applications","authors":"Sumit Kumar,&nbsp;Wenbin Zhong,&nbsp;Prashant Kumar,&nbsp;Paul Scott,&nbsp;Xiangqian Jiang,&nbsp;Wenhan Zeng","doi":"10.1016/j.optcom.2024.131345","DOIUrl":"10.1016/j.optcom.2024.131345","url":null,"abstract":"<div><div>The utilization of a multi-facial freeform monolithic (MFFM) component in a compact Cassegrain configuration design offers unprecedented capabilities to accommodate various next-generation science instruments. The concept of the MFFM component can be employed for applications in telescopes working at ultra-violet, optical, infrared, terahertz, microwave, and even radio frequencies. MFFM finds its scope in space optical and astronomical systems where the risks are associated with the alignment, manufacturability, and maintaining large-sized apertures, large number of components, cost, and volume of the flight optical terminals and instruments. The current challenges faced at the manufacturing phase of MFFM are the precision positioning of each surface concerning the optical axis and maintaining the required edge thickness. This paper presents the optical design, fabrication, measurement, and in-laboratory characterization of MFFM. The results of a prototyping effort through ultra-precision single-point diamond turning (SPDT) and coating demonstrate the feasibility of producing these elements as per size and weight requirements. The experimental results show excellent surface qualities in terms of nanometric surface roughness and close-to-submicron form accuracy on each surface of the freeform monolith. Focusing performance and imaging performance are carried out to validate the designed and manufactured precision component. The main contribution is highlighted in terms of the optimized fabrication process for producing the precision MFFM for a fast optical system while balancing the alignment errors. The demonstrated research work highlights the intriguing possibilities of the monolith and creates new avenues for research in domains that use huge optical systems, such as astrophysical study, planetary observation, earth monitoring, and geosciences.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"576 ","pages":"Article 131345"},"PeriodicalIF":2.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Hong-Ou-Mandel interference with a coexisting clock using transceivers for synchronization over deployed fiber","authors":"Anirudh Ramesh ,&nbsp;Daniel R. Reilly ,&nbsp;Kim Fook Lee ,&nbsp;Paul M. Moraw ,&nbsp;Joaquin Chung ,&nbsp;Md Shariful Islam ,&nbsp;Cristián Peña ,&nbsp;Xu Han ,&nbsp;Rajkumar Kettimuthu ,&nbsp;Prem Kumar ,&nbsp;Gregory S. Kanter","doi":"10.1016/j.optcom.2024.131305","DOIUrl":"10.1016/j.optcom.2024.131305","url":null,"abstract":"<div><div>Interference between independently generated photons is a key step towards distributing entanglement over long distances, but it requires synchronization between the distantly-located photon sources. Synchronizing the clocks of such photon sources using coexisting two-way classical optical communications over the same fiber that transports the quantum photonic signals is a promising approach for achieving photon–photon interference over long distances, enabling entanglement distribution for quantum networking using the deployed fiber infrastructure. Here, we demonstrate photon–photon interference by observing the Hong–Ou–Mandel dip between two distantly-located sources: a weak coherent-state source obtained by attenuating the output of a laser and a heralded single-photon source. We achieve a maximum dip visibility of <span><math><mrow><mn>0</mn><mo>.</mo><mn>58</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>04</mn></mrow></math></span> when the two sources are connected via 4.3 km of deployed fiber. Dip visibilities <span><math><mrow><mo>&gt;</mo><mn>0</mn><mo>.</mo><mn>5</mn></mrow></math></span> are nonclassical and a first step towards achieving teleportation over the deployed fiber infrastructure. In our experiment, the classical optical communication is achieved with <span><math><mrow><mo>−</mo><mn>21</mn></mrow></math></span> dBm of optical signal launch power, which is used to synchronize the clocks in the two independent, distantly-located photon sources. The impact of spontaneous Raman scattering from the classical optical signals is mitigated by appropriate choice of the quantum- and classical-channel wavelengths. All equipment used in our experiment (the photon sources and the synchronization setup) is commercially available. Finally, our experiment represents a scalable approach to enabling practical quantum networking with commercial equipment and coexistence with classical communications in optical fiber.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"576 ","pages":"Article 131305"},"PeriodicalIF":2.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Simultaneous sensing of axial strain and temperature based on a sensitivity-selectable all-fiber Lyot-like filter","authors":"Zhengyu Liu ,&nbsp;Rong Tian ,&nbsp;Haiwei Zhang ,&nbsp;Sibo Zhang ,&nbsp;Zhihong Chen ,&nbsp;Lifang Xue ,&nbsp;Wei Shi ,&nbsp;Jianquan Yao","doi":"10.1016/j.optcom.2024.131341","DOIUrl":"10.1016/j.optcom.2024.131341","url":null,"abstract":"<div><div>In this paper, an all-fiber Lyot-like filter with tunable free spectral range (FSR) and selectable sensitivity is proposed and experimentally demonstrated for simultaneous sensing of axial strain and temperature. Compared to the traditional fiber-based Lyot filter, the Lyot-like filter has an additional single-mode fiber (SMF) based polarization controller (PC), which is placed between two sections of polarization-maintaining fiber (PMF). In our experiment, the tunable FSR is achieved by adjusting the PC at a special angle, and a small FSR value of 6.58 nm and a large FSR value of 18.49 nm are obtained, respectively. Moreover, the experimental results show that the small FSR has low axial strain and temperature sensitivity, while that of the large FSR is high. By detecting the wavelength shifts of the filter spectra dip points, the simultaneous sensing of axial strain and temperature can be realized easily using a dual-parameter matrix. The proposed Lyot-like filter has the advantages of tunable FSR, selectable sensitivity, and simultaneous measurement of temperature and axial strain, which shows potential sensing applications in aerospace, chemical production, and bridge condition monitoring.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"576 ","pages":"Article 131341"},"PeriodicalIF":2.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}