Optics Communications最新文献

{"title":"Highly efficient single photon coupling via surface plasmons into single-mode optical fiber","authors":"Erfan Riyazi ,&nbsp;Mohammad Jamshidi ,&nbsp;Ali Esfandiar ,&nbsp;Morteza Jafari Siavashani ,&nbsp;Nader Sobhkhiz Vayghan","doi":"10.1016/j.optcom.2024.131270","DOIUrl":"10.1016/j.optcom.2024.131270","url":null,"abstract":"<div><div>Quanta of light (single photon) play as one of the building blocks of photonic based quantum computations, sensing, and communications. This makes a necessity to develop practical approaches for tuning, guiding, and coupling of single photons in photonic circuits for viable applications. Interaction and coupling efficiency of single photon into optical fibers is a technical bottleneck of quantum optics and should be addressed by novel design and materials. Here, we introduce a fiber-based micro-photonic design to directly coupling of the emitted single-photon to the core of a single mode fiber (SMF). The results of the simulation indicate that the emission of single photon source on a D-shaped SMF coated by a thin plasmonic film, provide remarkable amplifying of the evanescent field by confined surface plasmons into the SMF. The numerical analysis of different types and thicknesses of plasmonic materials by finite element method (FEM) is conducted to study the propagation vectors along the SMF as a function of the emission angle and wavelength of the single photon source. The results revealed that by the optimum thickness of the tantalum layer as novel plasmonic material, the best record of coupling efficiency can be achieved in the fiber optics communication region (<em>λ</em> ∼ 1550 nm). This approach sheds light on novel plasmonic-assisted coupling and promises a functional strategy for single photon manipulation in various fields of quantum optics.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131270"},"PeriodicalIF":2.2,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654661","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":"Nanoparticle doping as a way to enhance holmium fiber lasers efficiency","authors":"M. Kamrádek,&nbsp;I. Kašík,&nbsp;J. Aubrecht,&nbsp;P. Vařák,&nbsp;O. Podrazký,&nbsp;I. Bartoň,&nbsp;J. Pokorný,&nbsp;P. Peterka,&nbsp;P. Honzátko","doi":"10.1016/j.optcom.2024.131290","DOIUrl":"10.1016/j.optcom.2024.131290","url":null,"abstract":"<div><div>Highly-doped holmium fibers have been prepared using modified chemical vapor deposition in combination with nanoparticle-doping method. Within a series of various Al₂O₃ and Ho³⁺ concentrations, relations between fibers composition and their fluorescence and laser parameters have been studied. Al/Ho molar ratio equal to at least 50 was found to be the key factor for fibers with outstanding parameters. Fibers with slope efficiency above 80%, laser threshold below 100 mW and fluorescence lifetime up to 1.6 ms have been prepared. Thanks to high Al₂O₃ concentrations, obtained through nanoparticle doping, we were able to achieve high-performance fibers in a wide range of Ho³⁺ concentrations. An output power of 19 W with 81% slope efficiency was reached using fiber with almost 4000 ppm of Ho³⁺ and 10 mol.% of Al₂O₃. This result is encouraging for highly efficient high-power cladding-pumped holmium fiber lasers, and studied relations between fibers composition and their laser parameters will be used in the designing of such laser sources.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131290"},"PeriodicalIF":2.2,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654660","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":"Impact of receiver bandwidth on the performance of nonlinear volterra equalizer in IM/DD systems","authors":"Jaeyoon Kim,&nbsp;Hoon Kim","doi":"10.1016/j.optcom.2024.131288","DOIUrl":"10.1016/j.optcom.2024.131288","url":null,"abstract":"<div><div>Nonlinear electrical equalization is an effective means to compensate for nonlinear waveform distortions in short-haul intensity-modulation (IM)/direct-detection (DD) optical transmission systems. Nonlinear distortions contain broader spectral components than the original signal. Thus, a wide receiver bandwidth and high sampling rate are beneficial to effective compensation of nonlinear distortions. However, this leads to poor signal-to-noise ratio at the receiver. In this paper, we investigate the impact of receiver bandwidth on the performance of 2nd-order nonlinear Volterra equalizer in IM/DD transmission systems. Through the computer simulation and the experimental verification performed with 4-ary pulse amplitude modulation signals, we show that an optimum receiver bandwidth for bit-error ratio performance increases with the amount of nonlinear distortions in IM/DD systems. We also show that the sampling rate should also be increased to avoid the aliasing of the nonlinear distortion components. The cost of the receiver increased by the wider receiver bandwidth and higher sampling rate could be offset in part by the non-integer fractionally sampled nonlinear Volterra equalizer.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131288"},"PeriodicalIF":2.2,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654681","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":"Common-mode intensity noise suppression scheme in phase demodulation of 3×3 coupler based on ellipse fitting algorithm","authors":"Qiliang Xia ,&nbsp;Xuqiang Wu ,&nbsp;Xiaopeng Liu ,&nbsp;Jihao Zhang ,&nbsp;Wen Zhou ,&nbsp;Tengfei Wang ,&nbsp;Jinhui Shi ,&nbsp;Jiatong Luo ,&nbsp;Benli Yu","doi":"10.1016/j.optcom.2024.131291","DOIUrl":"10.1016/j.optcom.2024.131291","url":null,"abstract":"<div><div>Addressing the issue of light source intensity noise in the phase demodulation scheme of the 3 × 3 coupler, this paper proposes a common mode intensity noise suppression scheme for differential signals based on the Ellipse Fitting Algorithm (EFA). This scheme employs the EFA to correct the direct current (DC) components of the three interference signals output by the 3 × 3 coupler. One of the interference signals is selected as a self-reference signal, and the other two interference signals are then subtracted the self-reference signal to obtain differential signals. This effectively eliminates the common-mode intensity noise in the DC components of the interference signals before demodulation, preventing noise from being aliased into the demodulation results. Then, the EFA and ATAN are applied to the two differential signals for signal demodulation. Experimental results show that, compared with the EFA demodulation scheme, the noise floor of the system is reduced by an average of 18 dB, with a maximum reduction of 26 dB to 1.58 μrad/√Hz at 50 kHz, and the total harmonic distortion (THD) is less than 1%.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131291"},"PeriodicalIF":2.2,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654589","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":"Inverse design of ultra-compact high-efficiency broadband interlayer couplers based on random gratings","authors":"Xin Yan,&nbsp;Mengfan Chu,&nbsp;Yuwei Zhang,&nbsp;Xueguang Yuan,&nbsp;Yang'an Zhang,&nbsp;Jinnan Zhang,&nbsp;Xia Zhang","doi":"10.1016/j.optcom.2024.131287","DOIUrl":"10.1016/j.optcom.2024.131287","url":null,"abstract":"<div><div>Ultra-compact high-efficiency broadband interlayer couplers based on random gratings are inversely designed by particle swarm optimization algorithm. The optimal structure is obtained by adjusting the pixel state to achieve a maximum coupling efficiency in 1550 nm band. The two-layer coupler consists of two vertically overlapping inverse taper waveguides with random gratings. With a short coupling length of 4 μm and interlayer gap of 200 nm, the coupling efficiency reaches 93% at a wavelength of 1550 nm, and exceeds 90% over a broadband wavelength range of 1503∼1600 nm, for both TE and TM mode. The coupling efficiency can maintain no less than 90% at a large waveguide misalignment of &gt;100 nm, exhibiting high process error tolerance. The performance of the 4 μm-long inverse-designed coupler is higher than the conventional waveguide with a much large length of 10 μm. To achieve longer transmission distance, a tri-layer interlayer coupler is proposed by cascading two bi-layer couplers, which exhibits a remarkable coupling efficiency of 85% at a gap of 600 nm, more than 30 times higher than the bi-layer structure. This work may pave the way for the development of ultra-compact high-performance interlayer couplers supporting high-integration Si-based photonic integrated circuits.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131287"},"PeriodicalIF":2.2,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654652","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":"Formation of optical resonances at the initial stage of radiation destruction of disperse medium made of a transparent dielectric by means of a powerful laser","authors":"Vladimir V. Osipov ,&nbsp;Egor V. Tikhonov ,&nbsp;Vyacheslav V. Platonov ,&nbsp;Vasiliy V. Lisenkov","doi":"10.1016/j.optcom.2024.131276","DOIUrl":"10.1016/j.optcom.2024.131276","url":null,"abstract":"<div><div>By means of numerical simulation, we study optical resonances that arise when radiation from an ytterbium fiber laser (<em>λ</em> = 1065 ± 3.25 nm), a blue diode laser (<em>λ</em> = 450±8 nm) or a CO₂ laser (10.6 μm) is scattered on a single particle of a transparent dielectric (an oxide, a fluoride, ZnSe), as well as in an ensemble of randomly packed particles of various sizes. If the particle diameter is comparable to the radiation wavelength (but is no less than 3<em>λ</em>/4) then, at a certain ratio between the particle diameter, the refractive index of its material and the radiation wavelength, the particle becomes a microresonator. The maximum intensity of scattered radiation inside or outside such particle depends on the combination of the above-said parameters and can exceed the intensity of the incident radiation dozens of times. In case of a powder, the interference pattern is formed by all particles at once and, occurrence of an optical resonance is more likely. Even with a slight change in the radiation wavelength of an ytterbium laser or a blue diode laser (within the lasing line width), some particles in the powder become microresonators, while others cease to be microcavities. Therefore, concentration of scattered radiation of the ytterbium laser in individual particles plays a key role at the initial stage of optical destruction of the powder. As the experiment shows, this allows to overcome the threshold of optical destruction of porous targets made of various transparent substances (CaF₂, SiO₂, BaF₂, YbF₃, Fe:MgAl₂O₄, Al₂O₃, 1mol.%Nd:Y₂O₃, YSZ, TiO₂, ZnSe) by means of a radiation pulse from an ytterbium laser having low intensity (0.46 MW/cm²). With the refractive index of the material increasing from 1.429 (CaF₂) to 2.479 (TiO₂), the average delay in the formation of a laser plume decreases from 46 ms to 25 μs, i.e. by three orders of magnitude. This correlates with the fact that in the calculations, the maximum intensity of this laser's radiation scattered in the powder increases with n increasing. In compliance with this are the results of obtaining nanopowders from transparent oxides and ZnSe by means of pulse-periodic radiation of an ytterbium laser. Output of the nanopowder Yb_0.05:Y_1.95O₃:(ZrO₂)_0.05 with <em>n</em> = 1.901 (for Y₂O₃) is 15 g/h, and the maximum output (100 g/h) is realized in case of ZnSe (<em>n</em> = 2.482). At the same time, it is not possible to obtain nanopowder from CaF₂ (<em>n</em> = 1.429), because the moving target does not evaporate.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131276"},"PeriodicalIF":2.2,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654598","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":"Calibration experiments for dual-comb IPDA XCO2 measurements using a variable pressure absorption cell","authors":"Zheng Liu ,&nbsp;Jiqiao Liu ,&nbsp;Xiaopeng Zhu ,&nbsp;Fu Yang ,&nbsp;Tang Li ,&nbsp;Yunpeng Zhang ,&nbsp;Juxin Yang ,&nbsp;Weibiao Chen","doi":"10.1016/j.optcom.2024.131281","DOIUrl":"10.1016/j.optcom.2024.131281","url":null,"abstract":"<div><div>Measuring XCO₂, the column-averaged dry-air mixing ratio of CO₂ in the atmosphere, is essential for monitoring climate change and guiding mitigation efforts. Integrated Path Differential Absorption (IPDA) is a highly effective XCO₂ measurement solution for space-borne lidar. However, the limited number of wavelengths limits its capabilities. IPDA, enhanced with Electro-Optical Frequency Comb (EOFC) technology, offers a robust solution. This study validates IPDA measurements using both asymmetric and symmetric Electro-Optic Dual-Comb Spectroscopy (EO-DCS) systems at 1572 nm. This indoor experimental system does not operate in a true lidar mode, but focuses on IPDA measurements of XCO₂ through a transmission-style cell. We achieved atmospheric spectral transmittance by a variable pressure CO₂ absorption cell, correlating pressures from 425 to 470 mb to XCO₂ of 386.81–447.08 ppm. The XCO₂ measurements of asymmetric/symmetric systems both exhibit excellent linearity. Their linear fittings yielded the Root Mean Square Error (RMSE) as low as 0.198/0.064 ppm, and the Mean Absolute Percentage Errors (MAPE) was as low as 0.0386%/0.0140%. This level of measurement performance has never been demonstrated in other works. Accuracy was assessed by comparing IPDA results with a pressure gauge, and precision was confirmed through repetitive measurements (1000 times over 10 min) and Allan variance analysis. Notably, our system operates effectively without frequency stabilization, showing tolerance to laser frequency drift—a significant advantage for IPDA applications. The entire experiment was conducted in a comparison between asymmetric and symmetric systems, especially in the analysis of absorption line residuals. We discuss the error transfer from phase to spectral transmittance and its implications and explained why the residuals in the asymmetric system were larger. These results underscore the superior performance of EO-DCS IPDA in measuring XCO₂ and its promising potential for applications. To our knowledge, this is the only DCS IPDA calibration demonstration to date.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131281"},"PeriodicalIF":2.2,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654607","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":"Deep learning method for predicting the complex nonlinear dynamics of passively mode-locked fiber laser","authors":"Boyuan Zhang,&nbsp;Dongdong Han,&nbsp;Tiantian Li,&nbsp;Kaili Ren,&nbsp;Yipeng Zheng,&nbsp;Lipeng Zhu,&nbsp;Jiamin Gong,&nbsp;Zhanqiang Hui","doi":"10.1016/j.optcom.2024.131286","DOIUrl":"10.1016/j.optcom.2024.131286","url":null,"abstract":"<div><div>The dynamic evolution processes are highly complicated nonlinear dynamic processes in passively mode-locked fiber laser systems. Here, an artificial intelligence (AI) model is employed to predict the complex dynamic processes, which uses the long short-term memory network method, serving as an alternative to the numerical calculation of the nonlinear Schrödinger equation (NLSE). We specifically emphasize the complex evolution processes under different gain saturation energies, comparing the results predicted by the AI model with those simulated by the NLSE. The predicted results of the AI model are in good agreement with the simulated results of NLSE. The root mean square errors of test samples in this study are all below 0.15. Furthermore, with GPU acceleration, the AI model achieves a mean simulation time of 0.452 s for 6000 roundtrips, approximately 2391 times faster than the numerical solution of NLSE executed on a CPU.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131286"},"PeriodicalIF":2.2,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654608","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":"Cavity-enhanced induced coherence without induced emission","authors":"Minhaeng Cho ,&nbsp;Peter W. Milonni","doi":"10.1016/j.optcom.2024.131284","DOIUrl":"10.1016/j.optcom.2024.131284","url":null,"abstract":"<div><div>This paper presents a theoretical study of the enhancement of Zou-Wang-Mandel (ZWM) interferometry through cavity-enhanced spontaneous parametric down-conversion (SPDC) processes producing frequency-entangled biphotons. The ZWM interferometry shows the capability to generate interference effects between single signal photons via indistinguishability between the entangled idler photons. This paper extends the foundational principles of ZWM interferometry by integrating cavity-enhanced SPDCs, aiming to narrow photon bandwidths for improved coherence and photon pair generation efficiency, which is critical for applications in quantum information technologies, quantum encryption, and quantum imaging. This work explores the theoretical implication of employing singly resonant optical parametric oscillators within the ZWM interferometer to produce narrow-band single photons. By combining cavity-enhanced SPDCs with ZWM interferometry, this study fills a gap in current theoretical proposals, offering significant advancements in quantum cryptography and network applications that require reliable, narrow-band single photons.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131284"},"PeriodicalIF":2.2,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654585","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":"Broadband high birefringence and single-polarization hollow-core anti-resonant fibers with an elliptical-like core","authors":"Jiajia Ran ,&nbsp;Yichao Meng","doi":"10.1016/j.optcom.2024.131251","DOIUrl":"10.1016/j.optcom.2024.131251","url":null,"abstract":"<div><div>Due to the light-guiding mechanism of hollow-core anti-resonant fibers (HC-ARFs), the low overlap between core modes and anti-resonant layers poses a challenge in achieving high birefringence. To address this issue, we propose three high-birefringence HC-ARFs with an elliptical core and varying cladding compositions and conduct a detailed optimization and analysis for structure (c). Simulation results demonstrate that structure (a) and structure (b) provide high birefringence, broadband, and low-loss transmission properties. Specifically, structure (a) achieves a birefringence greater than <span><math><mrow><mn>1</mn><mo>.</mo><mn>3</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> over a 680 nm wavelength range, and structure (b) achieves a birefringence greater than <span><math><mrow><mn>1</mn><mo>.</mo><mn>6</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> over a 580 nm wavelength range, both maintaining fundamental mode (FM) loss below 1 dB/m. Structure (c) enhances birefringence by an order of magnitude and offers excellent single-polarization properties by introducing high-refractive-index material. At <span><math><mrow><mn>1</mn><mo>.</mo><mn>55</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>, structure (c) achieves a birefringence of <span><math><mrow><mn>0</mn><mo>.</mo><mn>98</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></math></span>, with a low FM loss for x-polarization of 0.01 dB/m and a polarization extinction ratio (PER) of 57450. Additionally, structure (c) exhibits low bend loss in the x-direction, with only 0.06 dB/m for a bend radius of 6 cm.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131251"},"PeriodicalIF":2.2,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654215","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}