{"title":"Experimental realization of orbital-angular-momentum-selective coherent perfect absorption.","authors":"Jinhao Wang, Zijian Zhang, Hao Luo, Changhui Shen, Yongxin Jing, Hongchen Chu, Xiaoxi Zhou, Yun Lai","doi":"10.1364/OL.559783","DOIUrl":"https://doi.org/10.1364/OL.559783","url":null,"abstract":"<p><p>Coherent perfect absorption (CPA) dependent on orbital angular momentum (OAM) has been proposed theoretically but so far has lacked experimental validation. Here, we design an OAM-selective coherent perfect absorber and experimentally validate this intriguing phenomenon. By combining a spiral phase plate, a polarization-conversion metasurface, and a conical cavity, an incident plane wave of linear polarization is converted into cylindrical waves with different OAMs in two dimensions, which impinges on a dual-layer cylindrical absorber composed of a ceramic core and an indium tin oxide (ITO) coating. Experimental results, coinciding well with numerical simulations, confirm the OAM-selective CPA for different OAMs. Our findings offer a practical approach for electromagnetic energy harvesting and sensing at subwavelength dimensions.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"50 9","pages":"3002-3005"},"PeriodicalIF":3.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144038996","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}
Optics lettersPub Date : 2025-05-01DOI: 10.1364/OL.559277
Philippe Réfrégier, Frédéric Galland, Julien Fade
{"title":"Polarization coherence frustration generated with propagation.","authors":"Philippe Réfrégier, Frédéric Galland, Julien Fade","doi":"10.1364/OL.559277","DOIUrl":"https://doi.org/10.1364/OL.559277","url":null,"abstract":"<p><p>It is shown that a polarization coherence un-frustrated field can become polarization coherence frustrated with propagation in vacuum. Each of the two necessary conditions for light to be polarization coherence un-frustrated, which correspond to different physical properties, can be lost with propagation in free space.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"50 9","pages":"2922-2925"},"PeriodicalIF":3.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143972276","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":"High efficiency and broadly wavelength-tunable mid-infrared nanosecond erbium-doped fiber laser pumped at ∼1.7 μm.","authors":"Tiantian Zhou, Jiadong Wu, Zhiyuan Dou, Xinrui Chu, Ning Li, Dongyang Liu, Xiangzhen Huang, Yi Feng, Lingling Yang, Lili Miao, Chujun Zhao","doi":"10.1364/OL.560283","DOIUrl":"https://doi.org/10.1364/OL.560283","url":null,"abstract":"<p><p>We demonstrate a high efficiency and broadly wavelength-tunable nanosecond mid-infrared (mid-IR) erbium (Er<sup>3+</sup>)-doped fluoride fiber laser pumped at ∼1.7 μm experimentally. In the continuous-wave operation regime, the mid-IR fiber laser output with a slope efficiency of approximately 40% has been obtained with a tuning range 143 nm spanning from 2695 nm to 2838 nm and a linewidth of 0.2 nm. While in the actively Q-switched mode, the mid-IR fiber laser modulated by the acousto-optic modulator (AOM) can deliver stable pulsed laser with a tunable range 133 nm from 2698 nm to 2831 nm, featuring a pulse width of 121 ns, a high signal-to-noise ratio of 50 dB, and an efficiency of 37% at a modulation frequency of 30 kHz. The experimental results highlight the superior efficiency of the pumping scheme and may provide an efficient and precise solution for practical applications.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"50 9","pages":"3062-3065"},"PeriodicalIF":3.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143997613","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}
Optics lettersPub Date : 2025-05-01DOI: 10.1364/OL.558464
Weiting Wang, Zihan Liu, Man Tao, Zan Zhang, Yujie Wu, Hongwei Gong, Zijing Zhang, Yantao Zheng, Shigen Ouyang, Dongmei Deng
{"title":"Enhancement and expansion of auto-focusing ability of polymorphic Pearcey beams.","authors":"Weiting Wang, Zihan Liu, Man Tao, Zan Zhang, Yujie Wu, Hongwei Gong, Zijing Zhang, Yantao Zheng, Shigen Ouyang, Dongmei Deng","doi":"10.1364/OL.558464","DOIUrl":"https://doi.org/10.1364/OL.558464","url":null,"abstract":"<p><p>In this work, a novel, to the best of our knowledge, zonal phase (ZP) modulation technique is introduced to solve the problem that the non-circular symmetric Pearcey beams (NCSPBs) lose relatively perfect auto-focusing ability. Our method efficiently improves the auto-focusing ability of the beams, achieves flexible control of the focus position or even generates multiple focusing effects, and is applicable to various forms of Pearcey beams. In addition, we have experimentally generated polymorphic Pearcey beams including unmodulation and ZP modulation, verifying the correctness of the theoretical analysis and the feasibility of the methodology. Our work provides an effective way for beam shaping, restoring and expanding the auto-focusing capability of other auto-focusing beams, with potential applications in periodic capture of multiple particles and enhancing free-space optical communication capabilities.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"50 9","pages":"2892-2895"},"PeriodicalIF":3.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144008143","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":"Ultra-low-latency 3D measurement with a 1D approximate de Bruijn pattern.","authors":"Xiaohang Shi, Qitong Guo, Ruoyu Jia, Chunxin Yang, Kenichi Murakami, Yuji Yamakawa","doi":"10.1364/OL.558411","DOIUrl":"https://doi.org/10.1364/OL.558411","url":null,"abstract":"<p><p>We proposed an ultra-low-latency projector-camera system for 3D imaging based on the one-dimensional de Bruijn pattern. The feature of this pattern is that four selected different 5-bit de Bruijn sequences form a 7-bit approximate de Bruijn sequence, thus increasing the number of codes while maintaining the short code length, which achieves the balance between precision and decoding speed. The one-dimension property adapts well to GPU acceleration. We measured various moving and deformable objects with different materials, colors, and contrasts, and the results performed very well. For the planar surface, the proposed system acquires 120.0K points per image, and the latency is 0.059 ms with 0.80-mm precision on average.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"50 9","pages":"3142-3145"},"PeriodicalIF":3.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144008190","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}
Optics lettersPub Date : 2025-05-01DOI: 10.1364/OL.562583
Shenghong Ye, Naoto Masutomi, Bo Li, Yoshiki Kamiura, Ryota Kaide, Ryo Doi, Yiqing Wang, Ming Che, Yuya Mikami, Yuta Ueda, Kazutoshi Kato
{"title":"Ultra-fast photonic frequency hopping driven by reflection-type transversal filter laser for anti-jamming terahertz communications.","authors":"Shenghong Ye, Naoto Masutomi, Bo Li, Yoshiki Kamiura, Ryota Kaide, Ryo Doi, Yiqing Wang, Ming Che, Yuya Mikami, Yuta Ueda, Kazutoshi Kato","doi":"10.1364/OL.562583","DOIUrl":"https://doi.org/10.1364/OL.562583","url":null,"abstract":"<p><p>In future 6G networks, photonic-based terahertz (THz) frequency-hopping (FH) spread spectrum systems are expected to evade jamming attacks by hopping across their wide bandwidth to secure carrier frequencies. However, the hopping range and hopping speed of current THz FH systems are constrained by the tuning capability of conventional thermo-optically wavelength tunable lasers, which is typically operated at millisecond-range transition time. This Letter proposed and demonstrated an anti-jamming THz FH system with a fast transition time of less than 49 ns by harnessing an ultra-fast wavelength-tunable laser leveraging the electro-optic effect. The system performed pseudo-random frequency hopping across three carrier frequencies from 240 GHz to 320 GHz with 40 GHz spacing, reaching <b>5 × 10<sup>6</sup></b> hops/s for enhanced jamming immunity. Additionally, we demonstrated the feasibility of 10 Gbit/s on-off keying (OOK) communication in the proposed system.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"50 9","pages":"3070-3073"},"PeriodicalIF":3.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143972256","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}
Optics lettersPub Date : 2025-05-01DOI: 10.1364/OL.562315
Zachary D Jones, Dominik Reitzle, Alwin Kienle
{"title":"Errors in diffuse optical absorption spectroscopy of two-layered turbid media due to assuming a homogeneous medium.","authors":"Zachary D Jones, Dominik Reitzle, Alwin Kienle","doi":"10.1364/OL.562315","DOIUrl":"https://doi.org/10.1364/OL.562315","url":null,"abstract":"<p><p>We investigate the errors in diffuse optical absorption spectroscopy of two-layered media when assuming a homogeneous medium as the reference model. Using analytical solutions of the radiative transfer equation, we obtain spatially resolved reflectance (SRR) curves in a two-layer model and fit these to determine absorption and scattering coefficients under the usually assumed single-layer simplification. Our results demonstrate two major findings: systematic errors in fitted absorption are a likely source of the so-called background absorption and that the degree of such errors is highly sensitive to the optical properties of the two layers and to the method of cost function calculation within the fitting method. Our findings provide an expectation of the errors that one may expect during <i>in vivo</i> chromophore concentration measurements of layered superficial tissue when using a single-layer homogenous model.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"50 9","pages":"3118-3121"},"PeriodicalIF":3.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144026080","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}
Optics lettersPub Date : 2025-05-01DOI: 10.1364/OL.554433
Sen Mei, Mulong Liu, Huimin Huang, Teng He, Zhizhou Lu, Wei Zhao
{"title":"Route to pure-quartic solitons in the mid-infrared.","authors":"Sen Mei, Mulong Liu, Huimin Huang, Teng He, Zhizhou Lu, Wei Zhao","doi":"10.1364/OL.554433","DOIUrl":"https://doi.org/10.1364/OL.554433","url":null,"abstract":"<p><p>Pure-quartic solitons (PQSs), as a new branch of soliton families, have attracted significant attention recently due to their potential in achieving higher energy than classical solitons for short pulse durations, providing innovations in nonlinear optics. Here, we report the excitation of PQSs at telecom and mid-infrared (MIR) wavelengths in silicon microcavities, enabled by slot waveguide structures for dominant fourth-order dispersion (FOD). We demonstrate that PQSs can be generated in the three-photon absorption (3 PA) and four-photon absorption (4 PA) regimes due to appropriate free-carrier (FC) lifetime or weak absorption coefficient, while PQSs are suppressed in the C-band ascribed to strong two-photon absorption (2 PA). Importantly, different PQS states are accessible by tuning the FC lifetime. Analytically, the approximate PQS solutions involving FOD and high-order nonlinearities are deduced with the Lagrangian perturbation method. These results provide a promising route to dispersion engineering for PQS formation in emerging platforms and shed new insights into understanding the dynamics of PQSs combined with multiphoton absorption (MPA) and FC effects.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"50 9","pages":"2848-2851"},"PeriodicalIF":3.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144027397","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}
Optics lettersPub Date : 2025-05-01DOI: 10.1364/OL.551386
D N Makarov, M K Eseev, E S Gusarevich, K A Makarova
{"title":"Ultrashort pulses in dynamic processes of crystal plates with ultrahigh temporal and spatial resolution.","authors":"D N Makarov, M K Eseev, E S Gusarevich, K A Makarova","doi":"10.1364/OL.551386","DOIUrl":"https://doi.org/10.1364/OL.551386","url":null,"abstract":"<p><p>Currently, the use of ultrashort pulses is one of the main methods for studying the structure and dynamics of ultrafast processes in atomic and molecular systems. In this paper, it is shown that ultrashort pulses can be used to determine the time dynamics of crystal plates with ultrahigh temporal and spatial resolution, the distance between which can be only a few angstroms. As an example, the dynamics of diamond layers with NV centers is considered. The results obtained have prospects for developing the presented theory for more complex structural objects and dynamic processes in matter.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"50 9","pages":"3078-3081"},"PeriodicalIF":3.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144021746","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}