Results in Optics最新文献

{"title":"Quantitative study of silicon waveguides for the generation of quantum correlated photon pairs bridging mid-infrared and telecom bands","authors":"Abhishek Kumar Pandey,&nbsp;Deepak Jain,&nbsp;Catherine Baskiotis","doi":"10.1016/j.rio.2026.101158","DOIUrl":"10.1016/j.rio.2026.101158","url":null,"abstract":"<div><div>Sources of quantum correlated photons pairs bridging the 3 μm–4 μm Mid-infrared (MIR) band and Telecom/Near-Infrared/Visible band are of high importance for quantum technologies. Spontaneous Parametric Down Conversion is generally used for realizing such sources, but requires costly implementation platforms with reduced versatility. Here, we explore the potentialities of Spontaneous Four-Wave Mixing (SFWM) in all-solid Silicon On Insulator (SOI) waveguides thanks to an experimentally validated model and propose designs ensuring the production of correlated photon pairs bridging the 3 μm–4 μm Mid-infrared band and Telecom C-band. Choosing a pump with a wavelength in the range 2100 nm–2210 nm and a pulse duration of 5 ps, we quantitatively performed simulations targeting a probability of photon pair generation per pulse of 0.05, and we found realistic conditions of utilization (2 cm-length straight waveguides, intra-modal Four Wave Mixing with the fundamental <span><math><msub><mi>TE</mi><mn>00</mn></msub></math></span> mode) with a pump peak power in between 9.2 mW and 32 mW. A first design (wCOM) reaches a signal wavelength as high as 3.905 μm, which is situated in an atmospheric transparency window, while maintaining an idler in the Telecom C-band, making it of high interest for atmospheric Quantum Key Distribution. Two other designs wCH₄ and wNO₂ aim precise CH₄ and NO₂ gas sensing with a signal wavelength of 3265 nm and 3461 nm respectively. In terms of signal/idler wavelength separation, wCOM attains the value of 2364 nm which is well above the current record of ∼1125 nm obtained in quantum regime with SFWM in all-solid SOI waveguides.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101158"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149045648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gouy phase for higher-order Gaussian modes","authors":"Nazarin Nizam,&nbsp;Dakshin Tillo,&nbsp;J. Solomon Ivan","doi":"10.1016/j.rio.2026.101176","DOIUrl":"10.1016/j.rio.2026.101176","url":null,"abstract":"<div><div>The Iwasawa decomposition of a ray transfer matrix and its unitary metaplectic counterpart is effectively used to solve for the evolution of a Hermite–Gaussian mode through a rotationally symmetric first-order optical system. Gouy phase as picked by an arbitrary Hermite–Gaussian mode with arbitrary width and quadratic phase on passage through a rotationally symmetric first-order optical system is obtained. The effect of width and quadratic phase of the input Hermite–Gaussian mode, position and momentum displacements, and composition of rotationally symmetric first-order optical systems, on the Gouy phase is obtained. It is seen that the Gouy phase acquired by a Hermite–Gaussian mode is intrinsic, and is retained even when there are position and momentum displacements on the mode while propagating through the desired optical system. The position and momentum displacements on the mode are seen to impart a transverse displacement to the mode, a tilt phase, and an overall displacement phase dependent on the system ray transfer matrix, over and above the Gouy phase and a propagation dependent phase. A method to tune the relative Gouy phases between the modes in a superposition by moving a single convex lens through a fixed distance, is outlined. The evolution of an arbitrary paraxial light field through any rotationally symmetric first-order optical system is in principle readily evaluated through the present method.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101176"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149155652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physics-regularized Chernoff-bound analysis of the quantum-illumination advantage through a plasma sheath","authors":"Sai Krishna Thota","doi":"10.1016/j.rio.2026.101184","DOIUrl":"10.1016/j.rio.2026.101184","url":null,"abstract":"<div><div>We ask whether the quantum-illumination (QI) advantage survives the lossy, thermally bright plasma sheath enveloping hypersonic vehicles. Computing the quantum Chernoff bound exactly in truncated Fock space for both QI and equal-energy classical illumination through an identical Appleton-type sheath channel, we find the advantage holds near +3.1 dB across transparent-to-moderate electron densities, then collapses beyond the blackout threshold and ultimately inverts deeper in the blackout regime, where round-trip loss destroys the signal–idler correlations. A physics-regularized residual surrogate makes a Gaussian proxy for the exponent ξ tractable across the full parameter space (RMSE = 0.513 ± 0.008 in log₁₀ ξ; R² = 0.951; 16.7% median error, versus 21.0% for a plain network; five seeds), degrading to 57.8% under out-of-distribution blackout conditions. We characterize this Gaussian proxy against exact Fock-space values in the entangled regime and find it underestimates the exact exponent by a factor of 3.7 to 5.0, decreasing with background, while preserving correct parameter ordering — reported explicitly so the surrogate is read as approximating a validated proxy rather than the exact bound.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101184"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149201544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vision-language models for fringe projection profilometry","authors":"Victoria MacDans,&nbsp;Yang Cheng,&nbsp;Hongyue Sun,&nbsp;Beiwen Li","doi":"10.1016/j.rio.2026.101147","DOIUrl":"10.1016/j.rio.2026.101147","url":null,"abstract":"<div><div>Fringe Projection Profilometry (FPP) enables high-resolution three-dimensional surface reconstruction. Its performance, however, is highly sensitive to acquisition parameters often tuned through expert judgment and trial-and-error, limiting robustness and scalability. To address this challenge, this paper proposes a vision-language model (VLM)–based diagnostic framework for assisting parameter tuning in FPP. The framework analyzes fringe images, reconstructed geometry, and textual prompts to identify parameter-induced artifacts and recommend corrective adjustments. Controlled experiments involving camera exposure, projector focus, and coupled misconfigurations were conducted. Across cases with misconfigurations of single parameters, the VLM identified dominant degradation sources and guided adjustments that reduced root-mean-square-error of depth maps. In scenarios with coupled misconfigurations of two parameters, iterative diagnostics improved quality of 3D surface reconstruction. These results demonstrate that VLMs can function as effective diagnostic assistants for FPP, enabling interpretable, visually grounded parameter tuning and reducing dependence on manual trial-and-error during acquisition.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101147"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148924561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Realization of square-root topology in plasmon-polaritonic system","authors":"Yi Fan","doi":"10.1016/j.rio.2026.101144","DOIUrl":"10.1016/j.rio.2026.101144","url":null,"abstract":"<div><div>The square-root operation can generate new topological states with their topological properties inherited from the parent Hamiltonian. In this letter, we construct the square-root topological system with a lattice of plasmon-polaritonic nanocavities. Using the system, we have realized square-root topological states in the visible light band with negligible long-range interactions and system dimensions in the micrometer range. We find distinct topological states like multiple edge states and non-degenerate corner states. These topological features enrich our understanding of square-root topology and pave the way for visible-light topological photonic devices with novel functionalities.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101144"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148939888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Self-healing in topologically protected polarization lattice structures","authors":"Rahul Joshi,&nbsp;Anuj Maurya,&nbsp;Sushanta Kumar Pal,&nbsp;Sunil Kumar,&nbsp;P. Senthilkumaran","doi":"10.1016/j.rio.2026.101164","DOIUrl":"10.1016/j.rio.2026.101164","url":null,"abstract":"<div><div>Topologically protected polarization lattice structures (TPPLSs) are lattices consisting of periodic arrays of C-point, V-point, and L-line polarization singularities that exhibit intricate topological properties and hold promise for robust polarization-sensitive applications. Such TPPLSs form a stable network bounded by topological sign rules, and the lattice is demonstrated to be resilient to obstructions. In this Letter, we experimentally demonstrate that the two key parameters of TPPLSs, i.e., helicity and topological index, remain preserved through a self-healing process during propagation. This resilience against obstructions highlights the inherent topological robustness of TPPLSs and points to their suitability for quantum information processing and other applications where preserving beam integrity during propagation is critical.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101164"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149155654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The thermal effects on the photonic band gaps of the two-dimensional SiO2-Si hexagonal photonic crystal","authors":"Chia-Ching Li,&nbsp;Sih-Yuan Wang,&nbsp;Sheng-Chun Weng,&nbsp;Qi-Lin Yang,&nbsp;Ting-Han Pei","doi":"10.1016/j.rio.2026.101146","DOIUrl":"10.1016/j.rio.2026.101146","url":null,"abstract":"<div><div>In this study, we investigate the thermal effects on the photonic band gaps of a two-dimensional SiO₂-Si hexagonal photonic crystal composed of a silicon dioxide (SiO₂) substrate with an array of silicon-filled holes. The photonic band structures of the transverse electric (TE) mode are calculated using the plane wave expansion method, and the thermal effects on the photonic band gaps are analyzed. Two temperature-dependent refractive-index models, namely the Ghosh model and the Sellmeier equation, are used to calculate the refractive indices of silicon dioxide. In addition, a temperature-dependent refractive-index function for silicon reported by H. H. Li is adopted at the target telecommunication wavelength of 1.55 μm, without considering the absorption coefficient. Using these experimentally based material parameters, well-converged numerical results are obtained. Eight photonic band gaps are initially identified below the normalized frequency <span><math><mi>ωa</mi><mo>/</mo><mn>2</mn><mi>πc</mi><mo>=</mo><mn>1.1</mn></math></span> over the temperature range from 200 K to 600 K. However, the sixth gap remains close to zero width and is excluded from the quantitative discussion because it is extremely narrow and may be affected by numerical convergence. Therefore, the remaining seven reliable photonic band gaps are analyzed in detail. The results show that lower-order band gaps exhibit relatively weak temperature dependence, whereas some higher-order band gaps show more pronounced thermal variation. These numerical results provide useful theoretical guidance for the development and optimization of future silicon photonic devices, such as waveguides and optical filters.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101146"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148924563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancement of birefringence in liquid crystals with graphene flakes in the infrared region","authors":"Tomoyuki Sasaki,&nbsp;Sora Ohara,&nbsp;Kohei Noda,&nbsp;Moritsugu Sakamoto,&nbsp;Nobuhiro Kawatsuki,&nbsp;Hiroshi Ono","doi":"10.1016/j.rio.2026.101135","DOIUrl":"10.1016/j.rio.2026.101135","url":null,"abstract":"<div><div>We report an enhancement of infrared birefringence in a liquid crystal (LC) induced by the addition of graphene flakes. Graphene flakes, with primary particle sizes ranging from approximately 0.5 to <span><math><mrow><mn>5</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>, were dispersed in a LC at various concentrations around 10⁻³ wt%, and the birefringence was evaluated using infrared lasers at wavelengths of <span><math><mrow><mn>3.85</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> and <span><math><mrow><mn>1.55</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>. We find that, with an appropriate additive concentration, the birefringence can increase by up to a factor of 1.5. The observed concentration dependence of the birefringence is characterized using a phenomenological model.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101135"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148924560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser-ablation synthesis and DFT investigation of anisotropic optical properties in multi-walled carbon nanotube/GaSe nanocomposites","authors":"A.M. Aliyeva,&nbsp;Vusala Nabi Jafarova,&nbsp;Khayala Ajdar Hasanova,&nbsp;Amirov Sh. Sh.,&nbsp;Adile Adem Guliyeva,&nbsp;V.M. Salmanov,&nbsp;Jihad H. Asad,&nbsp;R.M. Mamedov,&nbsp;Noorhan F. AlShaikh Mohammad","doi":"10.1016/j.rio.2026.101181","DOIUrl":"10.1016/j.rio.2026.101181","url":null,"abstract":"&lt;div&gt;&lt;div&gt;MWCNT/GaSe nanocomposites were synthesized by pulsed laser ablation in a liquid medium and investigated through complementary structural, spectroscopic, and polarization-resolved first-principles calculations. X-ray diffraction revealed pronounced broadening of the diffraction profile after nanocomposite formation, indicating reduced long-range structural order, while Debye–Scherrer analysis yielded coherent crystallite-domain sizes of approximately 7–15 nm. EDAX confirmed the presence of C, Ga, and Se, with Ga and Se contents of 7.60 and 7.99 at.%, respectively, corresponding to a nearly stoichiometric Ga:Se ratio of ∼1:1. SEM-based elemental mapping showed substantial spatial overlap of Ga and Se throughout the interconnected MWCNT network, although localized GaSe-rich clusters were also observed. TEM/HRTEM analysis further revealed direct nanoscale contact between GaSe-containing crystalline regions and the graphitic nanotube walls. A representative MWCNT exhibited outer and inner diameters of approximately 32 and 16 nm, respectively, with ∼7–9 graphitic walls and an interlayer spacing of ∼0.34 nm, while GaSe-containing crystalline regions displayed lattice fringes of ∼0.33–0.334 nm; complementary SAED measurements confirmed crystalline ordering within the nanocomposite. Optical absorption measurements and Tauc analysis showed a pronounced modification of the absorption edge, with the apparent optical gap decreasing from approximately 2.15 eV for pristine MWCNTs to 1.39 eV for the MWCNT/GaSe nanocomposite. Comparative photoluminescence measurements under excitation at ℏω = 2.34 eV revealed characteristic emission regions near 576 nm for pristine GaSe and 887 nm for pristine MWCNTs, whereas the nanocomposite exhibited an approximately fivefold enhancement in relative PL intensity together with a markedly broadened emission response spanning approximately 576–887 nm. To interpret these optical modifications, polarization-resolved DFT calculations were performed for pristine and GaSe-functionalized armchair (5,5)@(10,10) double-walled carbon nanotubes and pristine GaSe. The pristine DWCNT displayed pronounced direction-dependent optical transitions dominated by transverse polarization components, whereas GaSe functionalization produced substantial redistribution of the calculated optical spectral weight toward lower photon energies and a marked modification of the polarization dependence, with the xx component becoming dominant in the low-energy region. Pristine GaSe exhibited strong intrinsic optical anisotropy, including a pronounced low-energy zz-polarized response. The calculated spectral redistribution in the hybrid model is qualitatively consistent with the experimentally observed shift of the optical edge toward lower energies, although the polarization-resolved DFT spectra are not directly equated with the orientation-averaged experimental Tauc values. Overall, the experimental results demonstrate successful MWCNT/GaSe nanocompo","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101181"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149155650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LiNoPulse: ultrafast nonlinear pulse propagation in thin-film lithium niobate waveguides","authors":"D. Chamundeeswari,&nbsp;B. Kuppusamy,&nbsp;M. Thiruchenduran,&nbsp;J. Anitha,&nbsp;J. Vasanthapriya","doi":"10.1016/j.rio.2026.101166","DOIUrl":"10.1016/j.rio.2026.101166","url":null,"abstract":"<div><div>This study focuses on a numerical analysis of ultrafast nonlinear optical pulses in thin-film lithium niobate (TFLN) waveguides. It investigates the interaction of group-velocity dispersion (GVD), Kerr nonlinear self-phase modulation (SPM), confinement of optical pulses and propagation loss on the propagation and development of 1550 nm femtosecond optical pulses. Based on this, a Split-Step Fourier Method (SSFM) numerical model has been developed to simulate the temporal and spectral dynamics of short optical pulses propagation in the TFLN waveguide. Effective mode area, nonlinear coefficient, propagation distance and pulse parameter effects on the transmission efficiency and pulse preservation are studied systematically. The outcomes reveal that the propagation of the pulse shape is enhanced when the optical confinement is enhanced, which leads to an increase in the effective nonlinear coefficient and thus the strength of the nonlinear interaction, such that when dispersion and Kerr nonlinearity are balanced by making use of the suitable nonlinear phase shifts, the propagation of the pulse shape is enhanced. Best results in this optimized configuration are a transmission efficiency of 96.7%, an energy retention of 96.2% and the energy pulse preservation factor of 0.98 after a propagation distance of 14.8 mm. The minimum mode area assumed gives a nonlinear coefficient of ∼1.52 W^-1m^-1 for the considered mode. These results demonstrate the potential of TFLN waveguides for controlled ultrafast nonlinear pulse propagation and signal processing in integrated photonic systems. The proposed numerical framework provides a basis for optimizing waveguide geometry and nonlinear propagation conditions for high-speed optical communication and nonlinear integrated photonic applications.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101166"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149045664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}