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Keywords = vertical-cavity surface-emitting laser

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14 pages, 3287 KiB  
Article
Characterization of Chirp Properties of an 850 nm Single-Mode Multi-Aperture Vertical-Cavity Surface-Emitting Laser and Analysis of Transmission Performance over Multimode and Single-Mode Fibers
by Xin Chen, Nikolay Ledentsov, Abdullah S. Karar, Jason E. Hurley, Oleg Yu. Makarov, Hao Dong, Ahmad Atieh, Ming-Jun Li and Nikolay Ledentsov
Photonics 2025, 12(7), 703; https://doi.org/10.3390/photonics12070703 - 11 Jul 2025
Viewed by 350
Abstract
By measuring the transfer function of the single-mode multi-aperture vertical-cavity surface-emitting laser (SM MA VCSEL) transmitting over a long single-mode fiber at 850 nm, we confirm that the chirp of the SM MA VCSEL under study is dominated by transient chirp with an [...] Read more.
By measuring the transfer function of the single-mode multi-aperture vertical-cavity surface-emitting laser (SM MA VCSEL) transmitting over a long single-mode fiber at 850 nm, we confirm that the chirp of the SM MA VCSEL under study is dominated by transient chirp with an alpha value of −3.81 enabling a 19 GHz bandwidth over 10 km of single-mode fiber. The detailed measurement of the VCSEL with different bias currents also allows us to recover other key characteristics of the VCSEL, thereby enabling us to practically construct the optical eye diagrams that closely match the experimentally measured ones. The link-level transfer function can be obtained using an analytical equation including effects of modal dispersion and laser chirp–chromatic dispersion (CD) interaction for an MMF of a given length and bandwidth grade. The narrow linewidth and chirp characteristics of the SM MA VCSEL enable transmission performance that surpasses that of conventional MM VCSELs, achieving comparable transmission distances at moderate modal bandwidths for OM3 and OM4 fibers and significantly longer reaches when the modal bandwidth is higher. The transmission performance was also confirmed with the modeled eye diagrams using extracted VCSEL parameters. The chirp properties also provide sufficient bandwidth for SM MA VCSEL transmission over kilometer-scale lengths of single-mode fibers at a high data rate of 100G or above with sufficient optical power coupled into the fibers. Advanced transmission distances are possible over multimode and single-mode fibers versus chirp-free devices. Full article
(This article belongs to the Special Issue Advances in Multimode Optical Fibers and Related Technologies)
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21 pages, 3171 KiB  
Review
Self-Mode-Locking and Frequency-Modulated Comb Semiconductor Disk Lasers
by Arash Rahimi-Iman
Photonics 2025, 12(7), 677; https://doi.org/10.3390/photonics12070677 - 5 Jul 2025
Viewed by 536
Abstract
Optically pumped semiconductor disk lasers—known as vertical-external-cavity surface-emitting lasers (VECSELs)—are promising devices for ultrashort pulse formation. For it, a “SESAM-free” approach labeled “self-mode-locking” received considerable attention in the past decade, relying solely on a chip-related nonlinear optical property which can establish adequate pulsing [...] Read more.
Optically pumped semiconductor disk lasers—known as vertical-external-cavity surface-emitting lasers (VECSELs)—are promising devices for ultrashort pulse formation. For it, a “SESAM-free” approach labeled “self-mode-locking” received considerable attention in the past decade, relying solely on a chip-related nonlinear optical property which can establish adequate pulsing conditions—thereby suggesting a reduced reliance on a semiconductor saturable-absorber mirror (the SESAM) in the cavity. Self-mode-locked (SML) VECSELs with sub-ps pulse durations were reported repeatedly. This motivated investigations on a Kerr-lensing type effect acting as an artificial saturable absorber. So-called Z-scan and ultrafast beam-deflection experiments were conducted to emphasize the role of nonlinear lensing in the chip for pulse formation. Recently, in addition to allowing stable ultrashort pulsed operation, self-starting mode-locked operation gave rise to another emission regime related to frequency comb formation. While amplitude-modulated combs relate to signal peaks in time, providing a so-called pulse train, a frequency-modulated comb is understood to cause quasi continuous-wave output with its sweep of instantaneous frequency over the range of phase-locked modes. With gain-bandwidth-enhanced chips, as well as with an improved understanding of the impacts of dispersion and nonlinear lensing properties and cavity configurations on the device output, an enhanced employment of SML VECSELs is to be expected. Full article
(This article belongs to the Special Issue Laser Technology and Applications)
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13 pages, 1573 KiB  
Article
Modal Bandwidth Enhancement Through Launch Condition Optimization for High Data Rate VCSEL Transmission Over Multimode Fibers
by Xin Chen, Simit Patel, Hao Dong, Hao Chen, Jason E. Hurley, Nikolay Ledentsov and Ming-Jun Li
Photonics 2025, 12(7), 654; https://doi.org/10.3390/photonics12070654 - 28 Jun 2025
Cited by 1 | Viewed by 423
Abstract
Vertical-cavity surface-emitting laser (VCSEL)-based transmission over multimode fiber (MMF) has achieved data rates of 100G per lane and is progressing towards 200G/lane, which demands more modal bandwidth from MMF to ensure adequate transmission reach. We address the needs of higher modal bandwidth from [...] Read more.
Vertical-cavity surface-emitting laser (VCSEL)-based transmission over multimode fiber (MMF) has achieved data rates of 100G per lane and is progressing towards 200G/lane, which demands more modal bandwidth from MMF to ensure adequate transmission reach. We address the needs of higher modal bandwidth from the point of view of engineering VCSEL launch conditions. We explore the options for using subsets of 10 standard-based launch conditions by analyzing the measured encircled fluxes from commercial VCSEL transceivers over two options. By utilizing experimentally measured MMF data, we demonstrated a significant improvement in modal bandwidth with these options. The launch conditions also impact the wavelength dependence of modal bandwidth for VCSELs operating at wavelengths longer than 850 nm. We conducted detailed Monte Carlo simulation of the wavelength dependence of modal bandwidth over MMFs. For one launch condition option using a smaller area, the modal bandwidths are improved over the effective modal bandwidth (EMB), and favor very high data rate transmission by allowing the use of a smaller area photodetector. Full article
(This article belongs to the Special Issue Advances in Multimode Optical Fibers and Related Technologies)
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13 pages, 2741 KiB  
Article
Quantum-Well-Embedded InGaN Quantum Dot Vertical-Cavity Surface-Emitting Laser and Its Photoelectric Performance
by Zinan Hua, Hailiang Dong, Zhigang Jia, Wei Jia, Lin Shang and Bingshe Xu
Photonics 2025, 12(3), 276; https://doi.org/10.3390/photonics12030276 - 17 Mar 2025
Viewed by 780
Abstract
An electrically injected vertical-cavity surface-emitting laser (VCSEL) with quantum-well-embedded InGaN quantum dots (QDs) as the active region was designed. The InGaN QD size and cavity length were optimized using PICS3D simulation software to achieve a high-performance InGaN QD-embedded VCSEL. A comparative analysis between [...] Read more.
An electrically injected vertical-cavity surface-emitting laser (VCSEL) with quantum-well-embedded InGaN quantum dots (QDs) as the active region was designed. The InGaN QD size and cavity length were optimized using PICS3D simulation software to achieve a high-performance InGaN QD-embedded VCSEL. A comparative analysis between the InGaN QD VCSEL and the traditional InGaN quantum well VCSEL was conducted, and the results demonstrated that the InGaN QD VCSEL achieved higher stimulated recombination radiation and internal quantum efficiency. The threshold current was reduced to 4 mA, corresponding to a threshold current density of 5.1 kA/cm², and the output power reached 4.4 mW at an injection current of 20 mA. A stable single-longitudinal-mode output was also achieved with an output wavelength of 436 nm. The proposed novel quantum-well-embedded QD active-region VCSEL was validated through theoretical simulations, confirming its feasibility. This study provides theoretical guidance and key epitaxial structural parameters for preparing high-performance VCSEL epitaxial materials. Full article
(This article belongs to the Section Lasers, Light Sources and Sensors)
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15 pages, 4654 KiB  
Article
Multi-Channel Vibration Measurements Based on a Self-Mixing Vertical-Cavity Surface-Emitting Laser Array
by Wei Xia, Jingyu Yu, Sunan Shao, Zhengyu Qian, Hui Hao, Ming Wang and Dongmei Guo
Photonics 2025, 12(3), 178; https://doi.org/10.3390/photonics12030178 - 21 Feb 2025
Viewed by 610
Abstract
This paper studied a multi-channel self-mixing interferometric vibration measurement system based on a vertical-cavity surface-emitting laser array. A 1 × 8 laser array was utilized to irradiate multiple positions of a vibrating target to establish independent measurement channels. The reflected light beams, carrying [...] Read more.
This paper studied a multi-channel self-mixing interferometric vibration measurement system based on a vertical-cavity surface-emitting laser array. A 1 × 8 laser array was utilized to irradiate multiple positions of a vibrating target to establish independent measurement channels. The reflected light beams, carrying the vibration information of each position, were redirected back into the laser and coherently mixed with the original optical field, generating the self-mixing interference. The interferometric signals were measured by monitoring the junction voltage variations across the terminals of the VCSEL array. A denoising filtering method based on the variational mode decomposition with Hausdorff distance was proposed to improve the signal-to-noise ratio. Furthermore, the vibration waveforms of different positions were reconstructed using the Hilbert transform-based orthogonal phase demodulation technology. Both simulations on synthetic signals and experiments with real datasets were conducted to validate the feasibility and stability of the proposed method. Due to the array detection configuration, the system boasted a simple and compact structure, low power consumption, and easy extensibility, laying the groundwork for high accuracy and multi-dimensional vibration detection in industrial applications. Full article
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11 pages, 3582 KiB  
Article
Link Bandwidth and Transmission Capability of Single-Mode Multi-Aperture Vertical-Cavity Surface-Emitting Lasers at 100 G/Lane and 200 G/Lane over Multimode Fibers
by Xin Chen, Nikolay Ledentsov, Jason E. Hurley, Oleg Yu. Makarov, Ming-Jun Li and Nikolay Ledentsov
Photonics 2025, 12(2), 147; https://doi.org/10.3390/photonics12020147 - 11 Feb 2025
Cited by 3 | Viewed by 1089
Abstract
Single-mode (SM) vertical-cavity surface-emitting lasers (VCSELs) have often been demonstrated with an unusually long transmission reach at very high data rates while today’s multimode VCSEL transmission has been limited by the fiber modal bandwidth and bandwidth contributed by the VCSEL–chromatic dispersion interaction under [...] Read more.
Single-mode (SM) vertical-cavity surface-emitting lasers (VCSELs) have often been demonstrated with an unusually long transmission reach at very high data rates while today’s multimode VCSEL transmission has been limited by the fiber modal bandwidth and bandwidth contributed by the VCSEL–chromatic dispersion interaction under typical encircled flux launch condition. By using the same launch condition for VCSEL and modal bandwidth measurements, we studied the link bandwidth capability of SM multi-aperture (MA) VCSEL transmission. Using a multimode fiber with modal bandwidth under actual launch conditions moderately lower than OM4 threshold, we observed that the link bandwidth, with contributions from both modal bandwidth and laser–chromatic dispersion interaction, is higher than the corresponding modal bandwidths, which is very counter-intuitive. A detailed analysis reveals that the enhanced link bandwidth is contributed by both narrow laser linewidth and favorable laser–chromatic dispersion interaction. Through the study, we demonstrate that OM4 can meet link bandwidth requirements for 200/100 G/lane transmission over 100/200 m using SM MA VCSELs. Full article
(This article belongs to the Special Issue Next-Generation Vertical-Cavity Surface-Emitting Lasers)
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11 pages, 7029 KiB  
Article
Meter-Scale Long Connectorized Paper-like Polymer Waveguide Film for 100 Gbps Board-Level Optical Interconnects Application
by Xu Liu, Lin Ma, Ying Shi, Qiancheng Yu, Motoya Kaneta, Xu Sun and Zuyuan He
Polymers 2024, 16(23), 3350; https://doi.org/10.3390/polym16233350 - 29 Nov 2024
Cited by 1 | Viewed by 1125
Abstract
We design and fabricate meter-scale long connectorized paper-like flexible multimode polymer waveguide film with a large bandwidth-length product (BLP) for board-level optical interconnects application. The measured BLP of the multimode waveguide is greater than 57.3 GHz·m at a wavelength of 850 nm under [...] Read more.
We design and fabricate meter-scale long connectorized paper-like flexible multimode polymer waveguide film with a large bandwidth-length product (BLP) for board-level optical interconnects application. The measured BLP of the multimode waveguide is greater than 57.3 GHz·m at a wavelength of 850 nm under the strictest overfilled launch condition with a maximum length of 2.1 m and 10-dB insertion loss. The fabricated waveguide films are as flexible as regular printing paper and can be conveniently interfaced with standard mechanically transferable (MT) fiber connectors with low loss. The average insertion loss of the connectorized waveguide is about 0.042 dB/cm with inter-channel crosstalk as low as −46.4 dB, and the bending loss is less than 1 dB at a bending radius of 1 mm under the overfilled launch condition. We also demonstrate a vertical-cavity surface-emitting laser (VCSEL)-based single-lane 100 Gbps PAM4 transmission. Our results show that the meter-scale long paper-like polymer waveguide film has both excellent optical properties and large bandwidth and is ideal for high-speed board-level optical interconnects application with a single-lane data rate of 100 Gbps and beyond, especially those that have a strict requirement on the length of connection and compactness. Full article
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13 pages, 5289 KiB  
Article
Structure Design of UVA VCSEL for High Wall Plug Efficiency and Low Threshold Current
by Bing An, Yukun Wang, Yachao Wang, Zhijie Zou, Yang Mei, Hao Long, Zhiwei Zheng and Baoping Zhang
Photonics 2024, 11(11), 1012; https://doi.org/10.3390/photonics11111012 - 27 Oct 2024
Cited by 1 | Viewed by 1939
Abstract
Vertical-cavity surface emitting lasers in UVA band (UVA VCSELs) operating at a central wavelength of 395 nm are designed by employing PICS3D(2021) software. The simulation results indicate that the thickness of the InGaN quantum well and GaN barrier layers affect the emission efficiency [...] Read more.
Vertical-cavity surface emitting lasers in UVA band (UVA VCSELs) operating at a central wavelength of 395 nm are designed by employing PICS3D(2021) software. The simulation results indicate that the thickness of the InGaN quantum well and GaN barrier layers affect the emission efficiency of UVA VCSELs greatly, suggesting an optimal thicknesses of 2.2 nm for the well layer and 2.7 nm for the barrier layer. Additionally, an overall consideration of threshold current, series resistance, photoelectric conversion efficiency, and optical output power results in the optimized thickness of the ITO current spreading layer, ~20 nm. Furthermore, by employing a five-pair Al0.15Ga0.85N/GaN multi-quantum barrier electron blocking layer (EBL) instead of a single Al0.2Ga0.8N EBL, the device shows a ~51% enhancement in the optical output power and a ~48% reduction in the threshold current. The number of distributed Bragg reflector (DBR) pairs also plays crucial roles in the device’s photoelectric performance. The device designed in this study demonstrates a minimum lasing threshold of 1.16 mA and achieves a maximum wall plug efficiency of approximately 5%, outperforming other similar studies. Full article
(This article belongs to the Special Issue Next-Generation Vertical-Cavity Surface-Emitting Lasers)
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12 pages, 1919 KiB  
Article
Learning Gradient-Based Feed-Forward Equalizer for VCSELs
by Muralikrishnan Srinivasan, Alireza Pourafzal, Stavros Giannakopoulos, Peter Andrekson, Christian Häger and Henk Wymeersch
Photonics 2024, 11(10), 943; https://doi.org/10.3390/photonics11100943 - 7 Oct 2024
Viewed by 1502
Abstract
Vertical cavity surface-emitting laser (VCSEL)-based optical interconnects (OI) are crucial for high-speed data transmission in data centers, supercomputers, and vehicles, yet their performance is challenged by harsh and fluctuating thermal conditions. This paper addresses these challenges by integrating an ordinary differential equation (ODE) [...] Read more.
Vertical cavity surface-emitting laser (VCSEL)-based optical interconnects (OI) are crucial for high-speed data transmission in data centers, supercomputers, and vehicles, yet their performance is challenged by harsh and fluctuating thermal conditions. This paper addresses these challenges by integrating an ordinary differential equation (ODE) solver within the VCSEL communication chain, leveraging the adjoint method to enable effective gradient-based optimization of pre-equalizer weights. We propose a machine learning (ML) approach to optimize feed-forward equalizer (FFE) weights for VCSEL transceivers, which significantly enhances signal integrity by managing inter-symbol interference (ISI) and reducing the symbol error rate (SER). Full article
(This article belongs to the Special Issue Machine Learning Applied to Optical Communication Systems)
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11 pages, 5962 KiB  
Article
Stable Single-Mode 795 nm Vertical-Cavity Surface-Emitting Laser for Quantum Sensing
by Yongli Wang, Yang Zhang, Chuanchuan Li, Jian Li, Xin Wei and Lianghui Chen
Materials 2024, 17(19), 4872; https://doi.org/10.3390/ma17194872 - 4 Oct 2024
Viewed by 1945
Abstract
Vertical-cavity surface-emitting lasers (VCSELs) are essential for exhibiting single-transverse-mode output characteristics, which are critical for applications in quantum sensing, optical interconnection, and laser printing. In this study, we achieved stable single-transverse-mode lasing using extended-2λ-cavity with an oxide aperture diameter of 7.08 μm. The [...] Read more.
Vertical-cavity surface-emitting lasers (VCSELs) are essential for exhibiting single-transverse-mode output characteristics, which are critical for applications in quantum sensing, optical interconnection, and laser printing. In this study, we achieved stable single-transverse-mode lasing using extended-2λ-cavity with an oxide aperture diameter of 7.08 μm. The device demonstrated a high output power of 6.8 mW and a narrow linewidth of 49.8 MHz at room temperature. Additionally, it maintained stable single-mode emission at 794.8 nm and achieved a side-mode suppression ratio (SMSR) exceeding 40 dB within the temperature range of 25 °C~85 °C, thereby meeting the requirements of 87Rb atom quantum sensors. The fabricated device obtained high-power and narrow linewidth single-transverse-mode operation by a monolithic extended cavity without introducing additional processing procedures, which is expected to promote the commercial viability of VCSELs in quantum sensing. Full article
(This article belongs to the Special Issue Advances in Nanophotonic Materials, Devices, and Applications)
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25 pages, 7449 KiB  
Review
Progress in Research on Co-Packaged Optics
by Wenchao Tian, Huahua Hou, Haojie Dang, Xinxin Cao, Dexin Li, Si Chen and Bingxu Ma
Micromachines 2024, 15(10), 1211; https://doi.org/10.3390/mi15101211 - 29 Sep 2024
Cited by 5 | Viewed by 15878
Abstract
In the 5G era, the demand for high-bandwidth computing, transmission, and storage has led to the development of optoelectronic interconnect technology. This technology has evolved from traditional board-edge optical modules to smaller and more integrated solutions. Co-packaged optics (CPO) has evolved as a [...] Read more.
In the 5G era, the demand for high-bandwidth computing, transmission, and storage has led to the development of optoelectronic interconnect technology. This technology has evolved from traditional board-edge optical modules to smaller and more integrated solutions. Co-packaged optics (CPO) has evolved as a solution to meet the growing demand for data. Compared to typical optoelectronic connectivity technology, CPO presents distinct benefits in terms of bandwidth, size, weight, and power consumption. This study presents an overview of CPO, highlighting its fundamental principles, advantages, and distinctive features. Additionally, it examines the current research progress of two distinct approaches utilizing Vertical-Cavity Surface-Emitting Laser (VCSEL) and silicon photonics integration technology. Additionally, it provides a concise overview of the many application situations of CPO. Expanding on this, the analysis focuses on the CPO using 2D, 2.5D, and 3D packaging techniques. Lastly, taking into account the present technological environment, the scientific obstacles encountered by CPO are analyzed, and its future progress is predicted. Full article
(This article belongs to the Special Issue Advanced Packaging for Microsystem Applications, 3rd Edition)
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12 pages, 7899 KiB  
Article
A Modified Current-Mode VCSEL Driver for Short-Range LiDAR Sensor Applications in 180 nm CMOS
by Juntong Li, Yeojin Chon, Shinhae Choi and Sung-Min Park
Photonics 2024, 11(9), 868; https://doi.org/10.3390/photonics11090868 - 16 Sep 2024
Cited by 1 | Viewed by 1539
Abstract
This paper presents a modified current-mode vertical-cavity surface-emitting laser (VCSEL) driver as a transmitter for short-range light detection and ranging (LiDAR) sensors, where a stable bias generator is suggested with a regulated cascode current mirror circuit to provide the bias current of 1 [...] Read more.
This paper presents a modified current-mode vertical-cavity surface-emitting laser (VCSEL) driver as a transmitter for short-range light detection and ranging (LiDAR) sensors, where a stable bias generator is suggested with a regulated cascode current mirror circuit to provide the bias current of 1 mA with a trivial deviation of 5.4%, even at the worst-case process–voltage–temperature (PVT) variations. Also, a modified current-steering logic circuit is exploited with N-type MOSFET (NMOS) switches to deliver the modulation currents of 0.1~10 mApp to the VCSEL diode simultaneously, with no overshoot distortions. Post-layout simulations of the modified current-mode VCSEL driver (m-CMVD), using 180 nm CMOS technology, demonstrate very large and clean output pulses with significantly reduced signal distortions. Hereby, the VCSEL diode is transformed into an equivalent circuit with a 1.6 V DC voltage and a 50 Ω resistor for circuit simulations. The proposed m-CMVD consumes a maximum of 11 mW from a 3.3 V supply voltage and the chip core occupies an area of 0.196 mm2. Full article
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13 pages, 4538 KiB  
Article
Measuring Transverse Relaxation with a Single-Beam 894 nm VCSEL for Cs-Xe NMR Gyroscope Miniaturization
by Qingyang Zhao, Ruochen Zhang and Hua Liu
Sensors 2024, 24(17), 5692; https://doi.org/10.3390/s24175692 - 1 Sep 2024
Cited by 3 | Viewed by 1416
Abstract
The spin-exchange-pumped nuclear magnetic resonance gyroscope (NMRG) is a pivotal tool in quantum navigation. The transverse relaxation of atoms critically impacts the NMRG’s performance parameters and is essential for judging normal operation. Conventional methods for measuring transverse relaxation typically use dual beams, which [...] Read more.
The spin-exchange-pumped nuclear magnetic resonance gyroscope (NMRG) is a pivotal tool in quantum navigation. The transverse relaxation of atoms critically impacts the NMRG’s performance parameters and is essential for judging normal operation. Conventional methods for measuring transverse relaxation typically use dual beams, which involves complex optical path and frequency stabilization systems, thereby complicating miniaturization and integration. This paper proposes a method to construct a 133Cs parametric resonance magnetometer using a single-beam vertical-cavity surface-emitting laser (VCSEL) to measure the transverse relaxation of 129Xe and 131Xe. Based on this method, the volume of the gyroscope probe is significantly reduced to 50 cm3. Experimental results demonstrate that the constructed Cs-Xe NMRG can achieve a transverse relaxation time (T2) of 8.1 s under static conditions. Within the cell temperature range of 70 °C to 110 °C, T2 decreases with increasing temperature, while the signal amplitude inversely increases. The research lays the foundation for continuous measurement operations of miniaturized NMRGs. Full article
(This article belongs to the Special Issue Atomic Magnetic Sensors)
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13 pages, 1037 KiB  
Article
Neural Network Equalisation for High-Speed Eye-Safe Optical Wireless Communication with 850 nm SM-VCSELs
by Isaac N. O. Osahon, Ioannis Kostakis, Denise Powell, Wyn Meredith, Mohamed Missous, Harald Haas, Jianming Tang and Sujan Rajbhandari
Photonics 2024, 11(8), 772; https://doi.org/10.3390/photonics11080772 - 20 Aug 2024
Viewed by 1468
Abstract
In this paper, we experimentally illustrate the effectiveness of neural networks (NNs) as non-linear equalisers for multilevel pulse amplitude modulation (PAM-M) transmission over an optical wireless communication (OWC) link. In our study, we compare the bit-error-rate (BER) performances of two decision [...] Read more.
In this paper, we experimentally illustrate the effectiveness of neural networks (NNs) as non-linear equalisers for multilevel pulse amplitude modulation (PAM-M) transmission over an optical wireless communication (OWC) link. In our study, we compare the bit-error-rate (BER) performances of two decision feedback equalisers (DFEs)—a multilayer-perceptron-based DFE (MLPDFE), which is the NN equaliser, and a transversal DFE (TRDFE)—under two degrees of non-linear distortion using an eye-safe 850 nm single-mode vertical-cavity surface-emitting laser (SM-VCSEL). Our results consistently show that the MLPDFE delivers superior performance in comparison to the TRDFE, particularly in scenarios involving high non-linear distortion and PAM constellations with eight or more levels. At a forward error correction (FEC) threshold BER of 0.0038, we achieve bit rates of ~28 Gbps, ~29 Gbps, ~22.5 Gbps, and ~5 Gbps using PAM schemes with 2, 4, 8, and 16 levels, respectively, with the MLPDFE. Comparably, the TRDFE yields bit rates of ~28 Gbps and ~29 Gbps with PAM-2 and PAM-4, respectively. Higher PAM levels with the TRDFE result in BERs greater than 0.0038 for bit rates above 2 Gbps. These results highlight the effectiveness of the MLPDFE in optimising the performance of SM-VCSEL-based OWC systems across different modulation schemes and non-linear distortion levels. Full article
(This article belongs to the Special Issue Machine Learning Applied to Optical Communication Systems)
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7 pages, 2412 KiB  
Communication
Simulation of Modal Control of Metal Mode-Filtered Vertical-Cavity Surface-Emitting Laser
by Jingfei Mu, Yinli Zhou, Chao Chen, Xing Zhang, Jianwei Zhang, Tianjiao Liu, Zhuo Zhang, Yuehui Xu, Gaohui Yuan, Jiye Zhang, Yongqiang Ning and Lijun Wang
Sensors 2024, 24(14), 4700; https://doi.org/10.3390/s24144700 - 19 Jul 2024
Cited by 2 | Viewed by 1727
Abstract
In this study, a novel metal-dielectric film mode filter structure that can flexibly regulate the transverse mode inside vertical-cavity surface-emitting lasers (VCSELs) is proposed. The number, volume, and stability of transverse modes inside the VCSEL can be adjusted according to three key parameters—the [...] Read more.
In this study, a novel metal-dielectric film mode filter structure that can flexibly regulate the transverse mode inside vertical-cavity surface-emitting lasers (VCSELs) is proposed. The number, volume, and stability of transverse modes inside the VCSEL can be adjusted according to three key parameters—the oxide aperture, the metal aperture, and the distance between the oxide aperture and the metal aperture—to form a flexible window, and a new parameter is defined to describe the mode identification. This study provides a complete simulation theory basis and calculation method, which is of great significance for the optical mode control in VCSELs. Full article
(This article belongs to the Section Optical Sensors)
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