Pub Date : 2024-09-09DOI: 10.1109/JPHOT.2024.3456115
Shiyao Chang;Shanchi Wu;Nuo Huang;Yan-Yu Zhang;Yi-Jun Zhu;Chao Wang;Chen Gong
The delay jitter in the visible light communication (VLC) network is analyzed in this work. First, the delay jitter under single-user and multi-user scenarios is investigated and a closed-form expression is obtained, whose accuracy is verified by simulation. Second, through analyzing the delay jitter under two typical indoor light emitting diode (LED) layouts, we find that the mean user delay jitter under cellular layout is a little lower than that of square layout. Then, we study the delay jitter for mobile users, and the relationship among user movement speed, arrival rate and delay jitter in different scenarios. The delay jitter performance is evaluated assuming perfect coordinated multiple points (CoMP) transmission strategy in VLC network. Simulation results show that in the context of VLC, static users can experience an average delay jitter of up to $10^{-6}$ s, while mobile users can experience an average delay jitter of up to $10^{-5}$ s. Therefore, VLC network can provide users with good delay jitter performance and customized services to meet the higher service quality requirements of future users.
{"title":"Delay Jitter Analysis for VLC Under Indoor Industrial Internet of Things Scenarios","authors":"Shiyao Chang;Shanchi Wu;Nuo Huang;Yan-Yu Zhang;Yi-Jun Zhu;Chao Wang;Chen Gong","doi":"10.1109/JPHOT.2024.3456115","DOIUrl":"10.1109/JPHOT.2024.3456115","url":null,"abstract":"The delay jitter in the visible light communication (VLC) network is analyzed in this work. First, the delay jitter under single-user and multi-user scenarios is investigated and a closed-form expression is obtained, whose accuracy is verified by simulation. Second, through analyzing the delay jitter under two typical indoor light emitting diode (LED) layouts, we find that the mean user delay jitter under cellular layout is a little lower than that of square layout. Then, we study the delay jitter for mobile users, and the relationship among user movement speed, arrival rate and delay jitter in different scenarios. The delay jitter performance is evaluated assuming perfect coordinated multiple points (CoMP) transmission strategy in VLC network. Simulation results show that in the context of VLC, static users can experience an average delay jitter of up to \u0000<inline-formula><tex-math>$10^{-6}$</tex-math></inline-formula>\u0000 s, while mobile users can experience an average delay jitter of up to \u0000<inline-formula><tex-math>$10^{-5}$</tex-math></inline-formula>\u0000 s. Therefore, VLC network can provide users with good delay jitter performance and customized services to meet the higher service quality requirements of future users.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 5","pages":"1-15"},"PeriodicalIF":2.1,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10669786","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142181472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aiming at the problem that cracks with different shapes and scales on the exterior walls of high buildings are difficult to detect, this paper proposed a wall crack detection method for high-altitude cleaning robots by hybridizing the GAM attention mechanism and RepGFPN. First, the GAM attention mechanism was incorporated into the YOLOV5 backbone network to reduce information and amplify global features to improve the accuracy of feature extraction. Then, the neck network incorporated the RepFPN method to improve the descriptive ability of fused multi-scale features and to increase computational efficiency. Public datasets Concrete Crack Images for Classification, Mixed VOC2007, CrackForest-dataset-master, and UCMerced_LandUse were used for experimental validation. The ablation experiment results show that the average accuracy of mAP is improved by 13.5% after introducing the GAM attention mechanism under the yolov5 s original model, while the method in this paper (GR-YOLO) continues to improve by 4.7%. The experimental results show that the average accuracy mAP of the proposed method (GR-YOLO) is 24.0%, 47.1% and 41.0% higher than that of the model yolov5s + involution, yolov5s + p2 + involution and yolov5s + p2 + involution + CBAM, respectively. The method proposed in this article can more effectively improve the accuracy of crack detection and has important application prospects.
{"title":"A Hybrid Attention Mechanism and RepGFPN Method for Detecting Wall Cracks in High-Altitude Cleaning Robots","authors":"Haiqiao Liu;Lingding Li;Ya Li;Qing Long;Zhuoyu Chen","doi":"10.1109/JPHOT.2024.3453943","DOIUrl":"10.1109/JPHOT.2024.3453943","url":null,"abstract":"Aiming at the problem that cracks with different shapes and scales on the exterior walls of high buildings are difficult to detect, this paper proposed a wall crack detection method for high-altitude cleaning robots by hybridizing the GAM attention mechanism and RepGFPN. First, the GAM attention mechanism was incorporated into the YOLOV5 backbone network to reduce information and amplify global features to improve the accuracy of feature extraction. Then, the neck network incorporated the RepFPN method to improve the descriptive ability of fused multi-scale features and to increase computational efficiency. Public datasets Concrete Crack Images for Classification, Mixed VOC2007, CrackForest-dataset-master, and UCMerced_LandUse were used for experimental validation. The ablation experiment results show that the average accuracy of mAP is improved by 13.5% after introducing the GAM attention mechanism under the yolov5 s original model, while the method in this paper (GR-YOLO) continues to improve by 4.7%. The experimental results show that the average accuracy mAP of the proposed method (GR-YOLO) is 24.0%, 47.1% and 41.0% higher than that of the model yolov5s + involution, yolov5s + p2 + involution and yolov5s + p2 + involution + CBAM, respectively. The method proposed in this article can more effectively improve the accuracy of crack detection and has important application prospects.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 5","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10663935","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142181474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper demonstrates the transmission of variable bit rates NRZ streams over different lengths of perfluorinated graded-index plastic optical fiber GI-POF at wavelengths of 1550 and 1310 nm. Specifically, at $lambda$ = 1550 nm, 16, 14 and 12 Gbps of NRZ transmissions are demonstrated for 50 m GI-POF. Furthermore, at $lambda$ = 1310 nm, 10 and 8 Gbps NRZ transmissions are demonstrated for distances of 50, 100 and 200 m. The performance is evaluated for realized transmissions in terms of received bit-error rate versus transmitted optical power and is compared to back to back performance.
{"title":"GI-POF Transmission At Different Bit Rates, Fiber Lengths and Wavelengths: 1310 and 1550 Nm","authors":"Hossam Selmy;Gil Fernandes;Rogério Nogueira;Ricardo Oliveira","doi":"10.1109/JPHOT.2024.3454072","DOIUrl":"10.1109/JPHOT.2024.3454072","url":null,"abstract":"The paper demonstrates the transmission of variable bit rates NRZ streams over different lengths of perfluorinated graded-index plastic optical fiber GI-POF at wavelengths of 1550 and 1310 nm. Specifically, at \u0000<inline-formula><tex-math>$lambda$</tex-math></inline-formula>\u0000 = 1550 nm, 16, 14 and 12 Gbps of NRZ transmissions are demonstrated for 50 m GI-POF. Furthermore, at \u0000<inline-formula><tex-math>$lambda$</tex-math></inline-formula>\u0000 = 1310 nm, 10 and 8 Gbps NRZ transmissions are demonstrated for distances of 50, 100 and 200 m. The performance is evaluated for realized transmissions in terms of received bit-error rate versus transmitted optical power and is compared to back to back performance.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 5","pages":"1-6"},"PeriodicalIF":2.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10663839","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142181473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1109/JPHOT.2024.3453898
Shengjie Tang;Cheng Chen;Qi Qin;Xiaoping Liu
Photonic neural networks are emerging as promising computing platforms for artificial intelligence (AI). Particularly, integrated photonic unitary neural networks (IPUNNs) are capable of mitigating gradient vanishing/explosion problems when deeper neural networks are constructed. Furthermore, their optical implementations are also much simpler compared to non-unitary counterparts. Meanwhile, real-valued datasets still dominate AI research and the encoding strategy is critical for IPUNNs' performances. However, there are few studies to compare different encoding strategies of IPUNNs to represent these real-valued datasets and their impacts on IPUNNs' performances. Here, in the scope of encoding strategies for real-valued features, we first compare different schemes, such as phase, amplitude and hybrid encoding using numerical simulations, with benchmarks of decision boundary and image recognition tasks. These encoding strategies of IPUNNs are also compared to non-unitary real-valued neural networks (RVNNs) with trainable biases for the same benchmarks. The results suggest that phase encoding outperforms amplitude and hybrid encoding, and exhibits comparable performances to non-unitary RVNNs. To verify the numerical results, a 10×10 IPUNN chip is designed and fabricated. The phase encoding is chosen to be implemented because of its superior performances in numerical studies. We reconfigure the IPUNN chip to perform decision boundary and image recognition tasks by on-chip in-situ training. The experimental results match the simulations well. Our work provides insights for implementing reconfigurable IPUNNs in AI computing.
{"title":"Reconfigurable Integrated Photonic Unitary Neural Networks With Phase Encoding Enabled by In-Situ Training","authors":"Shengjie Tang;Cheng Chen;Qi Qin;Xiaoping Liu","doi":"10.1109/JPHOT.2024.3453898","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3453898","url":null,"abstract":"Photonic neural networks are emerging as promising computing platforms for artificial intelligence (AI). Particularly, integrated photonic unitary neural networks (IPUNNs) are capable of mitigating gradient vanishing/explosion problems when deeper neural networks are constructed. Furthermore, their optical implementations are also much simpler compared to non-unitary counterparts. Meanwhile, real-valued datasets still dominate AI research and the encoding strategy is critical for IPUNNs' performances. However, there are few studies to compare different encoding strategies of IPUNNs to represent these real-valued datasets and their impacts on IPUNNs' performances. Here, in the scope of encoding strategies for real-valued features, we first compare different schemes, such as phase, amplitude and hybrid encoding using numerical simulations, with benchmarks of decision boundary and image recognition tasks. These encoding strategies of IPUNNs are also compared to non-unitary real-valued neural networks (RVNNs) with trainable biases for the same benchmarks. The results suggest that phase encoding outperforms amplitude and hybrid encoding, and exhibits comparable performances to non-unitary RVNNs. To verify the numerical results, a 10×10 IPUNN chip is designed and fabricated. The phase encoding is chosen to be implemented because of its superior performances in numerical studies. We reconfigure the IPUNN chip to perform decision boundary and image recognition tasks by on-chip in-situ training. The experimental results match the simulations well. Our work provides insights for implementing reconfigurable IPUNNs in AI computing.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 5","pages":"1-11"},"PeriodicalIF":2.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10663838","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142173996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ever-increasing demand for the transmission capacity has stimulated intensive investigations, in terms of both new transmission window of standard single mode fiber (SSMF) and new fiber utilizing the spatial domain. Multi-band wavelength division multiplexing (WDM) transmission exploring the extended wavelength band, besides traditional C+L band, is an attractive solution for the rapid and cost-effective enhancement of transmission capacity. To this end, here we demonstrate the U-band WDM transmission over 125-km G.652.D fiber, when the C-band amplified spontaneous emission (ASE) source acts as the incoherent pump for Raman amplification (RA). Meanwhile, bidirectional long short-term memory neural network (BiLSTM-NN) is applied to inversely design the spectral shape of two C-band ASE sources. After the optimization through inverse design, the ROP variation at the U-band can be less than 1.2 dB under different net Raman gains. Consequently, we can experimentally achieve a net Raman gain of ∼15 dB over a 3 dB bandwidth of around 2.1 THz at the U-band, under the condition of distributed bidirectional Raman pump configuration. Finally, the performance of the U-band RA is experimentally verified by transmitting three-wavelength 20 GBaud DP-QPSK signals, when the threshold of 7% HD-FEC can be successfully reached.
对传输容量不断增长的需求激发了对标准单模光纤（SSMF）新传输窗口和利用空间域的新型光纤的深入研究。除了传统的 C+L 波段外，探索扩展波段的多波段波分复用（WDM）传输是一种极具吸引力的解决方案，可快速、经济地提高传输容量。为此，我们在此演示了 125 千米 G.652.D 光纤上的 U 波段波分复用传输，此时 C 波段放大自发辐射（ASE）源充当拉曼放大（RA）的非相干泵浦。同时，应用双向长短期记忆神经网络（BiLSTM-NN）对两个 C 波段 ASE 源的光谱形状进行反向设计。经过反设计优化后，在不同的净拉曼增益下，U 波段的 ROP 变化可小于 1.2 dB。因此，在分布式双向拉曼泵配置的条件下，我们可以在 U 波段约 2.1 THz 的 3 dB 带宽上实验实现 ∼15 dB 的净拉曼增益。最后，通过传输三波长 20 GBaud DP-QPSK 信号，实验验证了 U 波段 RA 的性能，成功达到了 7% HD-FEC 的阈值。
{"title":"Inverse Design of Incoherent Raman Pump Sources for U-Band WDM Transmission Over 125 km G.652.D Fiber","authors":"Tangyanjun Lan;Junjiang Xiang;Gai Zhou;Meng Xiang;Songnian Fu;Yuwen Qin","doi":"10.1109/JPHOT.2024.3453870","DOIUrl":"10.1109/JPHOT.2024.3453870","url":null,"abstract":"The ever-increasing demand for the transmission capacity has stimulated intensive investigations, in terms of both new transmission window of standard single mode fiber (SSMF) and new fiber utilizing the spatial domain. Multi-band wavelength division multiplexing (WDM) transmission exploring the extended wavelength band, besides traditional C+L band, is an attractive solution for the rapid and cost-effective enhancement of transmission capacity. To this end, here we demonstrate the U-band WDM transmission over 125-km G.652.D fiber, when the C-band amplified spontaneous emission (ASE) source acts as the incoherent pump for Raman amplification (RA). Meanwhile, bidirectional long short-term memory neural network (BiLSTM-NN) is applied to inversely design the spectral shape of two C-band ASE sources. After the optimization through inverse design, the ROP variation at the U-band can be less than 1.2 dB under different net Raman gains. Consequently, we can experimentally achieve a net Raman gain of ∼15 dB over a 3 dB bandwidth of around 2.1 THz at the U-band, under the condition of distributed bidirectional Raman pump configuration. Finally, the performance of the U-band RA is experimentally verified by transmitting three-wavelength 20 GBaud DP-QPSK signals, when the threshold of 7% HD-FEC can be successfully reached.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 5","pages":"1-6"},"PeriodicalIF":2.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10663998","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142181475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Obtaining the light source position from the image is an important solution for achieving link alignment in laser-based underwater wireless optical communication (UWOC) systems. However, in practical scenarios, the misalignment degree between the light source and camera is variable, and factors such as ambient light may introduce disturbances, leading to significant variations in the appearance of light spots in images. Existing research primarily relies on simple features like brightness, color, or shape, which makes it difficult to accurately obtain position information from these non-ideal images. In this paper, deep neural networks (DNNs) with strong feature extraction capabilities are introduced to automatically learn the patterns of the light source from diverse images. A detection architecture cascading an object detector and a keypoint detector is adopted, achieving better comprehensive performance in terms of accuracy and speed. To train and evaluate the deep learning model, we construct the UWOC Light Source Detection Benchmark (ULDB) dataset. This dataset comprises 2200 images captured in a standard swimming pool, covering a misalignment range far beyond existing studies. On the ULDB test set, the proposed detection method achieves an average precision (AP) of 99.1% and an average positioning error of 4.66 pixels, while the traditional method may frequently extract false light spots. To the best of our knowledge, the ULDB dataset is the first image dataset specifically designed for the task of link alignment between UWOC terminals.
{"title":"Deep Learning-Based Cascaded Light Source Detection for Link Alignment in Underwater Wireless Optical Communication","authors":"Bowen Jia;Wenmin Ge;Jingxuan Cheng;Zihao Du;Renming Wang;Guangbin Song;Yufan Zhang;Chengye Cai;Sitong Qin;Jing Xu","doi":"10.1109/JPHOT.2024.3453116","DOIUrl":"10.1109/JPHOT.2024.3453116","url":null,"abstract":"Obtaining the light source position from the image is an important solution for achieving link alignment in laser-based underwater wireless optical communication (UWOC) systems. However, in practical scenarios, the misalignment degree between the light source and camera is variable, and factors such as ambient light may introduce disturbances, leading to significant variations in the appearance of light spots in images. Existing research primarily relies on simple features like brightness, color, or shape, which makes it difficult to accurately obtain position information from these non-ideal images. In this paper, deep neural networks (DNNs) with strong feature extraction capabilities are introduced to automatically learn the patterns of the light source from diverse images. A detection architecture cascading an object detector and a keypoint detector is adopted, achieving better comprehensive performance in terms of accuracy and speed. To train and evaluate the deep learning model, we construct the UWOC Light Source Detection Benchmark (ULDB) dataset. This dataset comprises 2200 images captured in a standard swimming pool, covering a misalignment range far beyond existing studies. On the ULDB test set, the proposed detection method achieves an average precision (AP) of 99.1% and an average positioning error of 4.66 pixels, while the traditional method may frequently extract false light spots. To the best of our knowledge, the ULDB dataset is the first image dataset specifically designed for the task of link alignment between UWOC terminals.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 5","pages":"1-12"},"PeriodicalIF":2.1,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10663260","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142181476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1109/JPHOT.2024.3452232
Guozhong Lei;Haolong Jia;Wenchang Lai;Wenhui Wang;Wenda Cui;Yan Wang;Hao Liu;Kai Han
Single-pixel imaging (SPI) is a novel computational imaging technique which combines illumination light fields and single-pixel detection values to reconstruct the image. Therefore, the generation method of the illumination light fields affects the imaging efficiency and quality. We propose a spiral line array laser source which can generate random illumination light fields without periodicity in the normalized second-order correlation function g (2) . It also has a lower full width at half maxima value (FWHM). In numerical simulations and experiments, the compressed sensing based on total variation algorithm is adopted to reconstruct the image. We demonstrate that the novel array is capable of obtaining images of superior quality and resolution compared to existing array laser sources, including hexagonal and Fermat spiral arrays. Combined with the fiber lasers and electro-optical phase modulators, it is expected to achieve high-speed modulation for light fields and high emitting power. Therefore, this method has significant potential for application in remote target detection and recognition.
{"title":"High-Quality and Enhanced-Resolution Single-Pixel Imaging Based on Spiral Line Array Laser Source","authors":"Guozhong Lei;Haolong Jia;Wenchang Lai;Wenhui Wang;Wenda Cui;Yan Wang;Hao Liu;Kai Han","doi":"10.1109/JPHOT.2024.3452232","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3452232","url":null,"abstract":"Single-pixel imaging (SPI) is a novel computational imaging technique which combines illumination light fields and single-pixel detection values to reconstruct the image. Therefore, the generation method of the illumination light fields affects the imaging efficiency and quality. We propose a spiral line array laser source which can generate random illumination light fields without periodicity in the normalized second-order correlation function \u0000<italic>g</i>\u0000<sup>(2)</sup>\u0000. It also has a lower full width at half maxima value (FWHM). In numerical simulations and experiments, the compressed sensing based on total variation algorithm is adopted to reconstruct the image. We demonstrate that the novel array is capable of obtaining images of superior quality and resolution compared to existing array laser sources, including hexagonal and Fermat spiral arrays. Combined with the fiber lasers and electro-optical phase modulators, it is expected to achieve high-speed modulation for light fields and high emitting power. Therefore, this method has significant potential for application in remote target detection and recognition.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 5","pages":"1-10"},"PeriodicalIF":2.1,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10660306","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142159893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We report growth and characterization of n-Si/p-SnO x heterojunction using RF sputtering for deposition of p-type SnO x under controlled growth oxygen pressure over n-type silicon (Si) wafer. The heterojunction properties of Si/SnO x were varied by controlling the growth oxygen pressure of SnOx. Several characterization techniques, including PL (photoluminescence), AFM (atomic force microscopy), FESEM (field emission scanning electron microscopy), XRD, I-V characteristics and Hall measurement, were conducted to analyze the structural, optical, and electrical properties of the n-Si/p-SnOx heterojunction. The knee voltage (V knee ), or cut-in voltage, was calculated by analyzing the gradient of the dark current-voltage (J-V) curves when the bias was applied in the forward direction. The V knee values for type-I, type-II, and type-III n-Si/p-SnO x heterojunctions were determined to be 0.62 V, 0.84 V, and 1.0 V, respectively. The ideality factors (n 1 and n 2 ) were determined to be 1.52, 2.22, 3.52, and 8.41, 9.31, 10.34, respectively, for various heterojunction types. The reverse saturation current densities, J 01 and J 02 ranging from approximately 10 −7 to 10 −6 A/cm 2 , and 10 −5 to 10 −4 A/cm 2 , respectively. The objective of this experimental work is to investigate especially, the prospect of silicon /metal-oxide (Si/SnOx) based heterojunction to be used as optical sensors with tunable optoelectronic properties of SnOx.
{"title":"Experimental Investigation of Si/SnOx Heterojunction for Its Tunable Optoelectronic Properties","authors":"Manoj Kumar;Vivek Kumar Srivastava;M. Sudhakara Reddy;Ram Bharos Yadav;Manoj Sharma;Amrindra Pal;Purnendu Shekhar Pandey;Yadvendra Singh;Gyanendra Kumar Singh;Balkeshwar Singh","doi":"10.1109/JPHOT.2024.3452514","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3452514","url":null,"abstract":"We report growth and characterization of n-Si/p-SnO\u0000<sub>x</sub>\u0000 heterojunction using RF sputtering for deposition of p-type SnO\u0000<sub>x</sub>\u0000 under controlled growth oxygen pressure over n-type silicon (Si) wafer. The heterojunction properties of Si/SnO\u0000<sub>x</sub>\u0000 were varied by controlling the growth oxygen pressure of SnOx. Several characterization techniques, including PL (photoluminescence), AFM (atomic force microscopy), FESEM (field emission scanning electron microscopy), XRD, I-V characteristics and Hall measurement, were conducted to analyze the structural, optical, and electrical properties of the n-Si/p-SnOx heterojunction. The knee voltage (V\u0000<sub>knee</sub>\u0000), or cut-in voltage, was calculated by analyzing the gradient of the dark current-voltage (J-V) curves when the bias was applied in the forward direction. The V\u0000<sub>knee</sub>\u0000 values for type-I, type-II, and type-III n-Si/p-SnO\u0000<sub>x</sub>\u0000 heterojunctions were determined to be 0.62 V, 0.84 V, and 1.0 V, respectively. The ideality factors (n\u0000<sub>1</sub>\u0000 and n\u0000<sub>2</sub>\u0000) were determined to be 1.52, 2.22, 3.52, and 8.41, 9.31, 10.34, respectively, for various heterojunction types. The reverse saturation current densities, J\u0000<sub>01</sub>\u0000 and J\u0000<sub>02</sub>\u0000 ranging from approximately 10\u0000<sup>−7</sup>\u0000 to 10\u0000<sup>−6</sup>\u0000 A/cm\u0000<sup>2</sup>\u0000, and 10\u0000<sup>−5</sup>\u0000 to 10\u0000<sup>−4</sup>\u0000 A/cm\u0000<sup>2</sup>\u0000, respectively. The objective of this experimental work is to investigate especially, the prospect of silicon /metal-oxide (Si/SnOx) based heterojunction to be used as optical sensors with tunable optoelectronic properties of SnOx.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 5","pages":"1-7"},"PeriodicalIF":2.1,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10660480","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142174015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1109/JPHOT.2024.3451929
Alireza Lanjani;Benjamin McEwen;Vincent Meyers;David Hill;Winston K. Chan;Emma Rocco;Shadi Omranpour;F. Shahedipour-Sandvik
Quantum well infrared photodetectors (QWIPs) have been demonstrated to be a suitable candidate for IR detection applications. These detectors attracted increasing interest due to their design flexibility and broad spectral absorption from short wave (SWIR) to long wave infrared (LWIR) and high uniformity. In this paper, we demonstrate device design, growth, and characterization of a p -type Al x Ga 1-x N/GaN quantum well infrared photodetector (QWIP) for near IR absorption with 1.55 μm peak grown by metal organic chemical vapor deposition (MOCVD). Utilizing a p -QWIP allows for normal incidence light absorption due to the strong band mixing between heavy and light holes at k ≠ 0 which eliminates the need for light couplers such as grating and facilitates the fabrication of large focal plane arrays (FPAs). We developed MOCVD growth conditions to achieve nm-thick and smooth interfaces in QWIP. Sample characterizations including atomic force microscopy (AFM) show uniform surface morphology with RMS roughness ∼0.5 nm. Scanning transmission electron microscopy (STEM) was used to characterize layer thicknesses and interface roughness. We demonstrate energy band diagram simulation of an Al x Ga 1-x N/GaN p -QWIP by considering polarization chargers to determine the accurate band offset and adjust the absorption wavelength (ISBT energies). Our results show the feasibility of MOCVD-grown p -type Al x Ga 1-x N/GaN QWIP for IR absorption and open a pathway for further research and growth development on III-Nitride p -QWIPs, allowing growth and fabrication of large focal plane arrays.
{"title":"Design and Demonstration of MOCVD-Grown p-Type AlxGa1-xN/GaN Quantum Well Infrared Photodetector","authors":"Alireza Lanjani;Benjamin McEwen;Vincent Meyers;David Hill;Winston K. Chan;Emma Rocco;Shadi Omranpour;F. Shahedipour-Sandvik","doi":"10.1109/JPHOT.2024.3451929","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3451929","url":null,"abstract":"Quantum well infrared photodetectors (QWIPs) have been demonstrated to be a suitable candidate for IR detection applications. These detectors attracted increasing interest due to their design flexibility and broad spectral absorption from short wave (SWIR) to long wave infrared (LWIR) and high uniformity. In this paper, we demonstrate device design, growth, and characterization of a \u0000<italic>p</i>\u0000-type Al\u0000<sub>x</sub>\u0000Ga\u0000<sub>1-x</sub>\u0000N/GaN quantum well infrared photodetector (QWIP) for near IR absorption with 1.55 μm peak grown by metal organic chemical vapor deposition (MOCVD). Utilizing a \u0000<italic>p</i>\u0000-QWIP allows for normal incidence light absorption due to the strong band mixing between heavy and light holes at \u0000<italic>k</i>\u0000 ≠ 0 which eliminates the need for light couplers such as grating and facilitates the fabrication of large focal plane arrays (FPAs). We developed MOCVD growth conditions to achieve nm-thick and smooth interfaces in QWIP. Sample characterizations including atomic force microscopy (AFM) show uniform surface morphology with RMS roughness ∼0.5 nm. Scanning transmission electron microscopy (STEM) was used to characterize layer thicknesses and interface roughness. We demonstrate energy band diagram simulation of an Al\u0000<sub>x</sub>\u0000Ga\u0000<sub>1-x</sub>\u0000N/GaN \u0000<italic>p</i>\u0000-QWIP by considering polarization chargers to determine the accurate band offset and adjust the absorption wavelength (ISBT energies). Our results show the feasibility of MOCVD-grown \u0000<italic>p</i>\u0000-type Al\u0000<sub>x</sub>\u0000Ga\u0000<sub>1-x</sub>\u0000N/GaN QWIP for IR absorption and open a pathway for further research and growth development on III-Nitride \u0000<italic>p</i>\u0000-QWIPs, allowing growth and fabrication of large focal plane arrays.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 5","pages":"1-6"},"PeriodicalIF":2.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10659068","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142143630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Waveguide-integrated photodetectors (PDs) play a crucial role in mid-infrared (MIR) silicon photonics, serving vital functions in sensing and communication applications. III-V semiconductors are widely used in MIR PDs, and many state-of-the-art III-V PDs on Si still require complicated integration methods. Heteroepitaxial growth technology is a competitive approach for large-scale integration; however, buffers capable of simultaneously achieving heteroepitaxial growth and optical coupling are limited in the MIR region. In this paper, we report a waveguide-integrated InAs PD on Si, incorporating a GaAs/Ge buffer design based on interfacial misfit (IMF) technology. We optimize the geometric structure and calculate the optoelectronic properties at a wavelength of 3 μm. For our simulated parameters, the optimal PD achieves a responsivity of 2.77 A/W and a detectivity of 4.68×10 9 cm·Hz 1/2 ·W -1 at -1V. This work suggests a promising avenue to further develop high-detectivity and high-speed PDs for MIR silicon photonics.
{"title":"Design and Optimization of InAs Waveguide- Integrated Photodetectors on Silicon via Heteroepitaxial Integration for Mid- Infrared Silicon Photonics","authors":"Hua Ge;Hao Luo;Sheng-Yi Wang;Xiang Li;Pei Liu;Shi Pu;Ning Xu;Bo-Wen Jia","doi":"10.1109/JPHOT.2024.3450091","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3450091","url":null,"abstract":"Waveguide-integrated photodetectors (PDs) play a crucial role in mid-infrared (MIR) silicon photonics, serving vital functions in sensing and communication applications. III-V semiconductors are widely used in MIR PDs, and many state-of-the-art III-V PDs on Si still require complicated integration methods. Heteroepitaxial growth technology is a competitive approach for large-scale integration; however, buffers capable of simultaneously achieving heteroepitaxial growth and optical coupling are limited in the MIR region. In this paper, we report a waveguide-integrated InAs PD on Si, incorporating a GaAs/Ge buffer design based on interfacial misfit (IMF) technology. We optimize the geometric structure and calculate the optoelectronic properties at a wavelength of 3 μm. For our simulated parameters, the optimal PD achieves a responsivity of 2.77 A/W and a detectivity of 4.68×10\u0000<sup>9</sup>\u0000 cm·Hz\u0000<sup>1/2</sup>\u0000·W\u0000<sup>-1</sup>\u0000 at -1V. This work suggests a promising avenue to further develop high-detectivity and high-speed PDs for MIR silicon photonics.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 5","pages":"1-10"},"PeriodicalIF":2.1,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10648999","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142143631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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