In this paper, a 1×4 ultra-compact wavelength division multiplexing cascaded device(DMC) with an arbitrary splitting ratio based on adjoint topology optimization reverse design is proposed, which is approximately two orders of magnitude smaller than that of conventional waveguide devices. It can simultaneously perform wavelength demultiplexing, mode conversion, and arbitrary ratio power splitting. The DMC separates 1310 nm and 1550 nm wavelengths, converts the input light from fundamental transverse mode (TE0) to first-order transverse mode (TE1) and second-order transverse modes (TE2), and performs arbitrarily proportional power splitting of the converted higher-order light source.
{"title":"Reverse design of multifunctional cascade devices based on the adjoint method","authors":"Zhibin Wang, Zhengyang Li, Xuwei Hou, Jiutian Zhang","doi":"10.1016/j.photonics.2024.101275","DOIUrl":"https://doi.org/10.1016/j.photonics.2024.101275","url":null,"abstract":"<div><p>In this paper, a 1×4 ultra-compact wavelength division multiplexing cascaded device(DMC) with an arbitrary splitting ratio based on adjoint topology optimization reverse design is proposed, which is approximately two orders of magnitude smaller than that of conventional waveguide devices. It can simultaneously perform wavelength demultiplexing, mode conversion, and arbitrary ratio power splitting. The DMC separates 1310 nm and 1550 nm wavelengths, converts the input light from fundamental transverse mode (TE0) to first-order transverse mode (TE1) and second-order transverse modes (TE2), and performs arbitrarily proportional power splitting of the converted higher-order light source.</p></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141096074","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}
Pub Date : 2024-05-21DOI: 10.1016/j.photonics.2024.101277
Ceng Chang, Xuechao Li, Yawen Cai, Xiaolong Yan, Xing Wang
We theoretically studied the linear, third-order nonlinear and total optical absorption coefficient changes of a typical GaAs/Al0.3Ga0.7As quantum dot system under the influence of hydrostatic pressure and temperature. The influence of hydrostatic pressure and temperature on the system is treated within the framework of effective mass. In this method, the relative changes of linear and nonlinear absorption coefficients are obtained by using density matrix method and iterative method. In addition, we also reveal the mechanism of the influence of hydrostatic pressure and temperature on the nonlinear optical properties, which is of great significance for us to better understand the causes. We have shown that hydrostatic pressure and temperature change the effective mass, resulting in significant changes in the linear and nonlinear optical properties of the system. In addition, we also reveal the mechanism of the influence of effective mass on the nonlinear optical properties, which is of great significance for us to better understand the causes.
{"title":"Tunability of the nonlinear optical absorption in a GaAs/Ga0.7 Al0.3 As spherical quantum dots under external factors","authors":"Ceng Chang, Xuechao Li, Yawen Cai, Xiaolong Yan, Xing Wang","doi":"10.1016/j.photonics.2024.101277","DOIUrl":"10.1016/j.photonics.2024.101277","url":null,"abstract":"<div><p>We theoretically studied the linear, third-order nonlinear and total optical absorption coefficient changes of a typical GaAs/Al<sub>0.3</sub>Ga<sub>0.7</sub>As quantum dot system under the influence of hydrostatic pressure and temperature. The influence of hydrostatic pressure and temperature on the system is treated within the framework of effective mass. In this method, the relative changes of linear and nonlinear absorption coefficients are obtained by using density matrix method and iterative method. In addition, we also reveal the mechanism of the influence of hydrostatic pressure and temperature on the nonlinear optical properties, which is of great significance for us to better understand the causes. We have shown that hydrostatic pressure and temperature change the effective mass, resulting in significant changes in the linear and nonlinear optical properties of the system. In addition, we also reveal the mechanism of the influence of effective mass on the nonlinear optical properties, which is of great significance for us to better understand the causes.</p></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141145037","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}
Pub Date : 2024-05-09DOI: 10.1016/j.photonics.2024.101274
Kokou Firmin Fiaboe , Marina Raevskaia , Marko Perestjuk , Alberto Della-Torre , Thach Nguyen , Arnan Mitchell , Christelle Monat , Christian Grillet
In spectroscopy, having access to a wide range of wavelengths within the mid-infrared region is crucial for conducting thorough and versatile analyses. In our research, we successfully demonstrate numerically the generation of supercontinuum within a waveguide made of silicon nitride loaded onto lithium niobate on a sapphire substrate, with a specific focus on the mid-infrared wavelength range. By implementing effective lateral leakage and dispersion engineering techniques, we have significantly broadened our system’s spectral range, covering wavelengths from the near-infrared (near-IR) to the mid-infrared (mid-IR) regions. Our results indicate that when a silicon nitride-loaded lithium niobate waveguide is excited with a commercially available femtosecond fiber laser pump at 2070 nm, it has the capability to produce a supercontinuum that spans more than one octave within the mid-infrared wavelength range.
{"title":"Mid-IR supercontinuum generation in a silicon nitride loaded lithium niobate on sapphire waveguide","authors":"Kokou Firmin Fiaboe , Marina Raevskaia , Marko Perestjuk , Alberto Della-Torre , Thach Nguyen , Arnan Mitchell , Christelle Monat , Christian Grillet","doi":"10.1016/j.photonics.2024.101274","DOIUrl":"https://doi.org/10.1016/j.photonics.2024.101274","url":null,"abstract":"<div><p>In spectroscopy, having access to a wide range of wavelengths within the mid-infrared region is crucial for conducting thorough and versatile analyses. In our research, we successfully demonstrate numerically the generation of supercontinuum within a waveguide made of silicon nitride loaded onto lithium niobate on a sapphire substrate, with a specific focus on the mid-infrared wavelength range. By implementing effective lateral leakage and dispersion engineering techniques, we have significantly broadened our system’s spectral range, covering wavelengths from the near-infrared (near-IR) to the mid-infrared (mid-IR) regions. Our results indicate that when a silicon nitride-loaded lithium niobate waveguide is excited with a commercially available femtosecond fiber laser pump at 2070 nm, it has the capability to produce a supercontinuum that spans more than one octave within the mid-infrared wavelength range.</p></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140910219","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}
Pub Date : 2024-05-07DOI: 10.1016/j.photonics.2024.101276
M.A. Tumashov , Y. Yashno , S.A. Kuznetsov , P.A. Lazorskiy , A. Epstein , S.B. Glybovski
Compact and efficient devices for radiation beam manipulation are in increasing demand by terahertz technologies. Herein, we introduce an ultrathin metal-polymer photolithographic metagrating operating as a transmissive beam splitter with a wide refraction angle of 58∘ at sub-THz frequencies. Harnessing this recently proposed complex media platform, composed of sparse periodic arrays of meta-atoms, constraints of conventional metasurfaces with densely packed unit cells can be alleviated. The devised splitter, synthesized semianalytically and demonstrated experimentally, features deeply subwavelength thickness due to the unique manufacturing process employed, serving as a promising alternative to thick waveguide-based metagratings previously reported for this frequency range.
{"title":"A semianalytically synthesized ultrathin photolithographic metagrating for sub-THz beam splitting","authors":"M.A. Tumashov , Y. Yashno , S.A. Kuznetsov , P.A. Lazorskiy , A. Epstein , S.B. Glybovski","doi":"10.1016/j.photonics.2024.101276","DOIUrl":"10.1016/j.photonics.2024.101276","url":null,"abstract":"<div><p>Compact and efficient devices for radiation beam manipulation are in increasing demand by terahertz technologies. Herein, we introduce an ultrathin metal-polymer photolithographic metagrating operating as a transmissive beam splitter with a wide refraction angle of 58<sup>∘</sup> at sub-THz frequencies. Harnessing this recently proposed complex media platform, composed of sparse periodic arrays of meta-atoms, constraints of conventional metasurfaces with densely packed unit cells can be alleviated. The devised splitter, synthesized semianalytically and demonstrated experimentally, features deeply subwavelength thickness due to the unique manufacturing process employed, serving as a promising alternative to thick waveguide-based metagratings previously reported for this frequency range.</p></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141033677","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}
Pub Date : 2024-04-29DOI: 10.1016/j.photonics.2024.101273
Shibo Sun, Meiyu Chang, Mei Kong, Yameng Xu
The detectable range and sensitivity play a key role in the accuracy and range of applications available for lab-on-a-chip sensing systems. Here, we propose and numerically demonstrate an on-chip refractive index sensor simultaneously possessing wide detectable range and high sensitivity through monitoring the two-peak envelope spectrum of a subwavelength grating microring resonator. The principle lies in the combination of the envelope spectrum tracking scheme and the light field releasing in subwavelength grating waveguides. The structure of the subwavelength grating microring resonator is designed to adjust the wavelength dependence of its critical coupling condition, so that the two-peak envelope spectrum can be formed and centered at critically coupled wavelengths. By probing the drift of the two-peak envelope spectrum within the C+L band (1530–1625 nm), we lift the free spectral range constraint on the detectable range and broaden it up to 0.46 RIU. Meanwhile, a sensitivity of 444 nm/RIU is achieved. This investigation provides an attractive candidate for high performance integrated sensors, and thus may pave the way for lab-on-chip sensing, especially in application scenarios demanding both wide detectable range and high sensitivity.
{"title":"Two-peak envelope spectrum of a subwavelength grating microring resonator for wide-range and high-sensitivity refractive index sensing","authors":"Shibo Sun, Meiyu Chang, Mei Kong, Yameng Xu","doi":"10.1016/j.photonics.2024.101273","DOIUrl":"https://doi.org/10.1016/j.photonics.2024.101273","url":null,"abstract":"<div><p>The detectable range and sensitivity play a key role in the accuracy and range of applications available for lab-on-a-chip sensing systems. Here, we propose and numerically demonstrate an on-chip refractive index sensor simultaneously possessing wide detectable range and high sensitivity through monitoring the two-peak envelope spectrum of a subwavelength grating microring resonator. The principle lies in the combination of the envelope spectrum tracking scheme and the light field releasing in subwavelength grating waveguides. The structure of the subwavelength grating microring resonator is designed to adjust the wavelength dependence of its critical coupling condition, so that the two-peak envelope spectrum can be formed and centered at critically coupled wavelengths. By probing the drift of the two-peak envelope spectrum within the C+L band (1530–1625 nm), we lift the free spectral range constraint on the detectable range and broaden it up to 0.46 RIU. Meanwhile, a sensitivity of 444 nm/RIU is achieved. This investigation provides an attractive candidate for high performance integrated sensors, and thus may pave the way for lab-on-chip sensing, especially in application scenarios demanding both wide detectable range and high sensitivity.</p></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140842670","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}
Pub Date : 2024-04-26DOI: 10.1016/j.photonics.2024.101264
M. Dareini , S.R. Ghorbani , H. Arabi , S. Daqiqeh Rezaei
The design of plasmonic metasurfaces is often based on solving the Maxwell electromagnetic equations, which can be a time-consuming and expensive process considering many geometrical parameters that can limit design flexibility. To speed up the design flow, a model based on the classical transmission line theory is presented. The proposed equivalent circuit model can predict the plasmon resonance wavelength based on various geometrical parameters including dielectric thickness and disk diameter. In addition, unlike other reported circuit models, the developed model considers the nanostructure array pitch size, which is crucial in metasurface design. Comparison between the results obtained from circuit model and full wavelength simulation showed that the circuit parameters accurately determine the response of the structure. Finally, as a metasurface design demonstration, we utilized our model to simulate aluminum-based gap-plasmon nanodisk arrays for optimizing their optical response to maximize structural color saturation.
{"title":"Application of circuit model for gap-plasmon nanodisk resonators","authors":"M. Dareini , S.R. Ghorbani , H. Arabi , S. Daqiqeh Rezaei","doi":"10.1016/j.photonics.2024.101264","DOIUrl":"https://doi.org/10.1016/j.photonics.2024.101264","url":null,"abstract":"<div><p>The design of plasmonic metasurfaces is often based on solving the Maxwell electromagnetic equations, which can be a time-consuming and expensive process considering many geometrical parameters that can limit design flexibility. To speed up the design flow, a model based on the classical transmission line theory is presented. The proposed equivalent circuit model can predict the plasmon resonance wavelength based on various geometrical parameters including dielectric thickness and disk diameter. In addition, unlike other reported circuit models, the developed model considers the nanostructure array pitch size, which is crucial in metasurface design. Comparison between the results obtained from circuit model and full wavelength simulation showed that the circuit parameters accurately determine the response of the structure. Finally, as a metasurface design demonstration, we utilized our model to simulate aluminum-based gap-plasmon nanodisk arrays for optimizing their optical response to maximize structural color saturation.</p></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140813658","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}
Pub Date : 2024-04-17DOI: 10.1016/j.photonics.2024.101263
Varun S.V., Shadak Aee K.
In this work, we present wavelength splitting characteristics of whispering gallery modes in a system where two disks with different refractive indices are coupled together. This study utilizes finite difference time domain based simulations. The spectral changes caused by the presence of nanoparticles are analyzed, taking factors such as the number of nanoparticles, their size and distance from the surface of the disks into account. The investigation also encompasses the interaction of a thin nanolayer. Our findings demonstrate that the wavelength splitting is highly influenced by the specific disk where the nanoparticle or nanolayer is located. This distinct property sets it apart from conventional coupled disks with identical features. A perturbation theory of coupled structures has also been applied to gain insights into the simulation results.
{"title":"Wavelength splitting in coupled dissimilar disk resonators with nanoscatterers","authors":"Varun S.V., Shadak Aee K.","doi":"10.1016/j.photonics.2024.101263","DOIUrl":"10.1016/j.photonics.2024.101263","url":null,"abstract":"<div><p>In this work, we present wavelength splitting characteristics of whispering gallery modes in a system where two disks with different refractive indices are coupled together. This study utilizes finite difference time domain based simulations. The spectral changes caused by the presence of nanoparticles are analyzed, taking factors such as the number of nanoparticles, their size and distance from the surface of the disks into account. The investigation also encompasses the interaction of a thin nanolayer. Our findings demonstrate that the wavelength splitting is highly influenced by the specific disk where the nanoparticle or nanolayer is located. This distinct property sets it apart from conventional coupled disks with identical features. A perturbation theory of coupled structures has also been applied to gain insights into the simulation results.</p></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140760328","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}
Pub Date : 2024-04-17DOI: 10.1016/j.photonics.2024.101262
Kaifeng Li , Zhiyong Yin , Shuguang Li, Xili Jing
We have experimentally demonstrated an ultra-high sensitivity gold-based fiber refractive index (RI) sensor whose main structure is composed of multimode fiber (MMF) and photonic crystal fiber (PCF). The gold film is deposited on V-shaped PCF by magnetron sputtering, and sensing experiments are performed based on the principle of surface plasmon resonance (SPR). Numerical simulation results indicate that the cladding mode of the V-shaped PCF is more capable of stimulating the SPR effect than the core mode. The experimental results show that the RI measurement range of the sensor is 1.333–1.421, with a maximum sensitivity of 10015 nm/RIU. In addition to RI sensing, sensing probes can be coated with polydimethylsiloxane (PDMS) on a gold film for temperature sensing. For temperature detection, the range is from 10 to 100 °C and the maximum sensitivity is 3.5 nm/℃. Besides high sensitivity in RI measurement, the proposed sensor also has good sensing performance in temperature sensing. With the advantages of high sensitivity, good stability, and easy preparation, this sensor has become an important reference in the field of high-performance sensing.
我们通过实验展示了一种超高灵敏度的金基光纤折射率(RI)传感器,其主要结构由多模光纤(MMF)和光子晶体光纤(PCF)组成。金膜通过磁控溅射沉积在 V 型 PCF 上,并基于表面等离子体共振(SPR)原理进行了传感实验。数值模拟结果表明,V 型 PCF 的包层模式比核心模式更能激发 SPR 效应。实验结果表明,传感器的 RI 测量范围为 1.333-1.421,最大灵敏度为 10015 nm/RIU。除了 RI 传感之外,传感探针还可以在金膜上涂覆聚二甲基硅氧烷 (PDMS),用于温度传感。温度检测范围为 10 至 100 ℃,最大灵敏度为 3.5 nm/℃。除了在 RI 测量方面具有高灵敏度外,该传感器在温度传感方面也具有良好的传感性能。该传感器具有灵敏度高、稳定性好、易于制备等优点,在高性能传感领域具有重要的参考价值。
{"title":"Experimental study on ultra-high sensitivity gold-based SPR sensor for refractive index and temperature measurement","authors":"Kaifeng Li , Zhiyong Yin , Shuguang Li, Xili Jing","doi":"10.1016/j.photonics.2024.101262","DOIUrl":"10.1016/j.photonics.2024.101262","url":null,"abstract":"<div><p>We have experimentally demonstrated an ultra-high sensitivity gold-based fiber refractive index (RI) sensor whose main structure is composed of multimode fiber (MMF) and photonic crystal fiber (PCF). The gold film is deposited on V-shaped PCF by magnetron sputtering, and sensing experiments are performed based on the principle of surface plasmon resonance (SPR). Numerical simulation results indicate that the cladding mode of the V-shaped PCF is more capable of stimulating the SPR effect than the core mode. The experimental results show that the RI measurement range of the sensor is 1.333–1.421, with a maximum sensitivity of 10015 nm/RIU. In addition to RI sensing, sensing probes can be coated with polydimethylsiloxane (PDMS) on a gold film for temperature sensing. For temperature detection, the range is from 10 to 100 °C and the maximum sensitivity is 3.5 nm/℃. Besides high sensitivity in RI measurement, the proposed sensor also has good sensing performance in temperature sensing. With the advantages of high sensitivity, good stability, and easy preparation, this sensor has become an important reference in the field of high-performance sensing.</p></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140755936","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}
Pub Date : 2024-04-09DOI: 10.1016/j.photonics.2024.101261
Kaizhu Liu , Yuxiang Yang , Xue Han , Changsen Sun , Chengchao He , Yanhong Li , Hsiang-Chen Chui
Manipulating surface plasmon polariton waves for the development of micro-nano devices has been widely studied in recent years. Two-dimensional artificial photonic crystals have bandstructure characteristics like semiconductors. However, the requirement for light to be incident along the structural periodic direction poses a challenge in coupling light into the photonic crystal, thereby impeding its integrations and applications. In this work, we proposed coupling vertically incident left-circularly polarized light into a photonic crystal waveguide using a chiral plasmonic lens. Linearly-polarized light can also generate surface plasmon polariton waves and couple them into photonic crystal waveguides, but the intensity is lower. In contrast, right-circularly polarized light propagates in the opposite direction and exhibits minimal propagation into the photonic crystal waveguide. The results indicate that the proposed structure can operate broadband within the wavelength range of 620–670 nm. This method provides a simple and easily integrated coupling method for photonic crystal devices.
{"title":"Vertical coupling to photonic crystal waveguide using chiral plasmonic lenses","authors":"Kaizhu Liu , Yuxiang Yang , Xue Han , Changsen Sun , Chengchao He , Yanhong Li , Hsiang-Chen Chui","doi":"10.1016/j.photonics.2024.101261","DOIUrl":"https://doi.org/10.1016/j.photonics.2024.101261","url":null,"abstract":"<div><p>Manipulating surface plasmon polariton waves for the development of micro-nano devices has been widely studied in recent years. Two-dimensional artificial photonic crystals have bandstructure characteristics like semiconductors. However, the requirement for light to be incident along the structural periodic direction poses a challenge in coupling light into the photonic crystal, thereby impeding its integrations and applications. In this work, we proposed coupling vertically incident left-circularly polarized light into a photonic crystal waveguide using a chiral plasmonic lens. Linearly-polarized light can also generate surface plasmon polariton waves and couple them into photonic crystal waveguides, but the intensity is lower. In contrast, right-circularly polarized light propagates in the opposite direction and exhibits minimal propagation into the photonic crystal waveguide. The results indicate that the proposed structure can operate broadband within the wavelength range of 620–670 nm. This method provides a simple and easily integrated coupling method for photonic crystal devices.</p></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140539207","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}
Pub Date : 2024-04-08DOI: 10.1016/j.photonics.2024.101260
Ivan Alonso Lujan-Cabrera, Cesar Isaza, Ely Karina Anaya-Rivera, Cristian Felipe Ramirez-Gutierrez
This work proposes an inverse design tool for porous silicon photonic structures. This tool is based on 2D-convolutional mixture density neural networks given that this type of architecture allows to tackle the nonuniqueness problem present in the optical response of photonic crystals. Moreover, a preprocessing reshaping method was implemented to use 2D-convolution neural networks due to their powerful ability in pattern recognition. A data set of porous silicon photonic spectra was generated. The photonic structures consist of 12 assembled layers of different thicknesses and porosities, generating incommensurate one-dimensional photonic crystals. The model was tested with four test data sets. First, a periodic validation was carried out, showing that incommensurate structures can generate well-defined photonic bandgaps. The second test set found that incommensurate photonic structures can resemble the optical response of a modulated photonic crystal and retrieve defective modes within the bandgap. The third test data set consisted of ideal distributed Bragg reflectors. It was found that the neural network could not predict accurate design due to the notorious differences in the optical properties of the two structures. Last, the neural network was tested with the experimental spectrum of a porous silicon photonic crystal, and it was shown that the predictions made were inaccurate because the simulations did not consider critical experimental aspects.
{"title":"Inverse design of incommensurate one-dimensional porous silicon photonic crystals using 2D-convolutional mixture density neural networks","authors":"Ivan Alonso Lujan-Cabrera, Cesar Isaza, Ely Karina Anaya-Rivera, Cristian Felipe Ramirez-Gutierrez","doi":"10.1016/j.photonics.2024.101260","DOIUrl":"https://doi.org/10.1016/j.photonics.2024.101260","url":null,"abstract":"<div><p>This work proposes an inverse design tool for porous silicon photonic structures. This tool is based on 2D-convolutional mixture density neural networks given that this type of architecture allows to tackle the nonuniqueness problem present in the optical response of photonic crystals. Moreover, a preprocessing reshaping method was implemented to use 2D-convolution neural networks due to their powerful ability in pattern recognition. A data set of porous silicon photonic spectra was generated. The photonic structures consist of 12 assembled layers of different thicknesses and porosities, generating incommensurate one-dimensional photonic crystals. The model was tested with four test data sets. First, a periodic validation was carried out, showing that incommensurate structures can generate well-defined photonic bandgaps. The second test set found that incommensurate photonic structures can resemble the optical response of a modulated photonic crystal and retrieve defective modes within the bandgap. The third test data set consisted of ideal distributed Bragg reflectors. It was found that the neural network could not predict accurate design due to the notorious differences in the optical properties of the two structures. Last, the neural network was tested with the experimental spectrum of a porous silicon photonic crystal, and it was shown that the predictions made were inaccurate because the simulations did not consider critical experimental aspects.</p></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140539208","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}