- 标题
- 摘要
- 关键词
- 实验方案
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Surface plasmon resonance on blue GaN-based VCSEL with Al-grating
摘要： Based on the research of surface plasmon (SP) applied to Vertical-Cavity Surface-Emitting Lasers (VCSEL), we proposed a new 465 nm GaN-based VCSEL to enhance illumination by deposit Al rectangular grating onto p-i-n layer. Meanwhile, an increase in the e?ective radiated power was obtained by the control of a surface plasmon mode, which depends strongly on the structural parameters such as material, period, depth and dipole location. Compared to conventional structure, we have a 30% improvement in e?ective radiated power. Such advantages make surface Al-grating be an alternative low-cost and simple technique used in SP-coupled VCSEL for the blue range.
关键词： Finite-di?erence time-domain method,Metal grating,Surface plasmon,Vertical-cavity surface-emitting laser (VCSEL)
更新于2025-09-23 15:23:52
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Error correction for short-range optical interconnect using COTS transceivers
摘要： Nowadays, quantities of commercial off-the-shelf (COTS) optical transceivers are widely equipped in both exiting and abuilding data centers. As data centers are becoming larger and containing more servers, the method to ensure longer and steady transmission with COTS optical transceivers becomes one of the key issues. Meanwhile, variations in the manufacturing of COTS optical transceivers bring in fluctuation of packet error rate (PER) in communication. In this paper, we present an application layer adaptive forward error correction (AL-AFEC) coding scheme for COTS optical transceivers in optical interconnect to solve the problems mentioned above and test its performance in a 10 Gbps Ethernet (10GbE) link using 10GBASE-SR SFP+ modules. Experimental results show that the proposed scheme enables longer transmission distance and the instability introduced by manufactural variations is well settled. Since our scheme requires no extra hardware on optical transceivers, it is a considerable low-cost alternative to improve system reliability and achieve longer transmission distance for COTS optical transceivers.
关键词： short-range optical interconnect,ethernet,vertical cavity surface emitting laser (VCSEL),application layer adaptive forward error correction,commercial off-the-shelf optical transceiver
更新于2025-09-23 15:23:52
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[IEEE 2018 41st International Conference on Telecommunications and Signal Processing (TSP) - Athens, Greece (2018.7.4-2018.7.6)] 2018 41st International Conference on Telecommunications and Signal Processing (TSP) - Studying an Optimal Approach to Design Combined Fiber-Wireless Telecom Systems
摘要： We proposed a new approach to design interface hardware for next-generation telecom systems of combined fiber-wireless architecture based on nonlinear behavioral modeling in widespread off-the-shelf CAD tool NI AWRDE. To validate the approach, we research in detail a prospective base station operating in EU-assigned band (3.4-3.8 GHz) of 5G networks, which has easy-to-configure layout using the same cost- and power-efficient LW-VCSEL in downlink and uplink channels and direct modulation of LW-VCSEL in period-doubling state.
关键词： fronthaul fiber-wireless architecture,vertical cavity surface-emitting laser,base station,fifth-generation telecom network,computer-aided design
更新于2025-09-23 15:22:29
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Highly efficient surface-emitting semiconductor lasers exploiting quasi-crystalline distributed feedback photonic patterns
摘要： Quasi-crystal distributed feedback lasers do not require any form of mirror cavity to amplify and extract radiation. Once implemented on the top surface of a semiconductor laser, a quasi-crystal pattern can be used to tune both the radiation feedback and the extraction of highly radiative and high-quality-factor optical modes that do not have a defined symmetric or anti-symmetric nature. Therefore, this methodology offers the possibility to achieve efficient emission, combined with tailored spectra and controlled beam divergence. Here, we apply this concept to a one-dimensional quantum cascade wire laser. By lithographically patterning a series of air slits with different widths, following the Octonacci sequence, on the top metal layer of a double-metal quantum cascade laser operating at THz frequencies, we can vary the emission from single-frequency-mode to multimode over a 530-GHz bandwidth, achieving a maximum peak optical power of 240 mW (190 mW) in multimode (single-frequency-mode) lasers, with record slope efficiencies for multimode surface-emitting disordered THz lasers up to ≈570 mW/A at 78 K and ≈720 mW/A at 20 K and wall-plug efficiencies of η ≈ 1%.
关键词： quantum cascade laser,surface-emitting,Quasi-crystal,THz frequencies,Octonacci sequence,semiconductor lasers,distributed feedback
更新于2025-09-23 15:21:01
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Evaluation of Chirped Fiber Bragg Grating with APD on Designed Optical Fiber Communication Link
摘要： Application of fiber Bragg grating (FBG) in optical communication is an evolving field. In this research paper, various types of chirped FBG’s (CFBG) have been used with avalanche photodiode (APD) on the designed optical fiber communication (OFC) link. Data rate of 20 Gbps and return-to-zero modulation format has been kept as fixed parameters. The designed link has been evaluated for varying fiber lengths (100, 200, 300, 400 and 500 km), various type of CFBG’s (linear, quadratic, square root and cubic root) with Gaussian apodization function, varying grating lengths (10, 20, 30, 40 and 50 mm) and operating temperatures (5°C, 10°C, 15°C, 20°C, 25°C, 30°C). The designed OFC link has also been evaluated for APD with and without CFBG. The performance evaluation matrix parameters selected are Q-factor, bit error rate and eye diagram. The OFC link employing CFBG with APD has been found to be superior. In compensating chromatic dispersion, optimum results have been observed for linear CFBG with Gaussian apodization function in comparison to other types of CFBG with 50 mm grating length for the maximum transmission distance.
关键词： bit error rate (BER),Optical fiber communication (OFC),eye diagram,chirped fiber Bragg grating (CFBG),vertical cavity surface emitting laser (VCSEL),avalanche photodiode (APD),Q-factor
更新于2025-09-23 15:19:57
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Optical Gain in Laser Heterostructures with an Active Area Based on an InGaAs/InGaAlAs Superlattice
摘要： An active area based on InGaAs/InGaAlAs superlattice for laser diodes operating in the spectral range between 1535 and 1565 nm is proposed and realized practically. It is demonstrated that using a superlattice increases the mode gain at the same values of the pump-diode current density relative to a typical active-area design based on an array of InGaAs quantum wells.
关键词： superlattice,quantum well,molecular beam epitaxy,vertical-cavity surface-emitting laser,heterostructure,active area
更新于2025-09-23 15:19:57
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Study of fabrication and characterization of high power 850a?ˉnm vertical-cavity surface-emitting laser arrays
摘要： In this paper, we investigated high power selectively oxidation-confined AlxGa1-xAs/GaAs 850 nm vertical-cavity surface-emitting laser (VCSEL) and fabricated two-dimensional VCSEL arrays by photolithography using photo masks. Inductively coupled plasma (ICP) was employed to create the deep platform during the mesa process. The number of illuminating lasers has been designed at 60, 85, and 109 in the array. We further studied the influence of the number of illuminating lasers on the characteristics of the VCSEL devices. The threshold current was found to be increased significantly at about 93 mA, 118 mA, 149 mA, respectively. The injection current should produce a greater than the critical current density to meet the criteria for population inversion. However, the corresponding voltage remained almost unchanged, in the range of 1.57~1.63 V. The maximum optical output power was increased even more appreciably. It was measured at 448 mW, 592 mW, and 746 mW, respectively. On the other hand, the device equivalent series resistance was decreased with more illumination lasers in the array. The averaged resistance has been estimated at 4.16 Ω, 3.14 Ω, and 2.47 Ω, respectively. In addition, the optical spectrum became more dispersed, showing more lasing modes for the samples with the highest number in illumination lasers in the array. The peak wavelength full width at half-maximum was also slightly increased. The related electro-optical characteristics have been summarized and further discussed.
关键词： High power,Inductively coupled plasma,Laser array,Surface emitting
更新于2025-09-23 15:19:57
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Impact of Chirp in High-Capacity Optical Metro Networks Employing Directly-Modulated VCSELs
摘要： Directly modulated long-wavelength vertical cavity surface emitting lasers (VCSELs) are considered for the implementation of sliceable bandwidth/bitrate variable transceivers for very high capacity transmission (higher than 50 Gb/s per wavelength) in metropolitan area systems characterized by reduced cost, power consumption, and footprint. The impact of the frequency chirp measured for InP VCSELs with different kinds of design (high-bandwidth very short cavity and widely-tunable with micro electro-mechanical systems (MEMS) top mirror) is analyzed in case of discrete multitone (DMT) direct modulation in combination with 25-GHz wavelength selective switch (WSS) filtering. The maximum transmitted capacity for both dual side- and single side-band DMT modulation is evaluated as a function of the number of crossed nodes in a mesh metro network, comparing VCSEL based transmitters performance also with the case of external electro-absorption modulator use. Finally, the maximum reach achieved based on the received optical signal to noise ratio (OSNR) and the fiber span length is discussed. The results confirm the possibility to use directly-modulated long-wavelength VCSELs for the realization of sliceable bandwidth/bitrate variable transmitters targeting 50-Gb/s capacity per polarization, also in the presence of 5 crossed WSSs for reaches of hundreds of kilometers in multi-span Erbium-doped fiber amplified (EDFA) metro links supported by coherent detection.
关键词： optical communications,vertical cavity surface emitting lasers,discrete multitone,metro networks,direct modulation
更新于2025-09-19 17:15:36
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Buried‐Tunnel Junction Current Injection for InP‐Based Nanomembrane Photonic Crystal Surface Emitting Lasers on Silicon
摘要： Herein, the design, metal-organic vapor-phase epitaxial growth, fabrication, and characterization of buried-tunnel junction (BTJ) current injection structures for InP/Si hybrid nanomembrane photonic crystal surface emitting lasers (PCSELs) are reported. Corresponding BTJ-light-emitting diodes on InP substrate show low series resistance and uniform carrier injection over square-shaped device areas with side length ranging from 15 up to 250 μm, whereas BTJ-PCSEL structures with similar current injection con?guration fabricated on photonic-crystal silicon-on-insulator substrate using transfer print technology show signi?cant linewidth narrowing at low current density.
关键词： photonic-crystal surface emitting lasers,buried-tunnel junctions,photonic bandedge lasers,silicon photonics,surface emitting lasers
更新于2025-09-19 17:13:59
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High power edge-cum-surface emitting terahertz laser arrays phased locked by vacuum guided plasmon waves
摘要： Terahertz semiconductor quantum-cascade lasers (QCLs) are widely implemented with metallic cavities that support low-loss plasmonic optical modes at long wavelengths. However, resonant optical modes in such cavities suffer from poor radiative characteristics due to their subwavelength transverse dimensions. Consequently, single-mode terahertz QCLs with metallic cavities and large (>100 mW) output power have only been realized in the surface-emitting con?guration that affords a large radiating surface. Here, we demonstrate a method to enhance radiative outcoupling from such plasmonic lasers for high-power emission in the edge-emitting (end-?re or longitudinal) direction. Single-sided plasmon waves propagating in vacuum are resonantly excited in surrounding medium of metallic cavities with the QCL semiconductor medium. The vacuum guided plasmon waves with a large wavefront phase-lock multiple metallic cavities longitudinally, which leads to intense radiation in multiple directions, including that in the longitudinal direction in a narrow single-lobed beam. The multicavity array radiates predominantly in a single spectral mode. A peak-power output of 260 mW and a slope ef?ciency of 303 mW/A are measured for the end-?re beam from a 3:3 THz QCL operating at 54 K in a Stirling cooler. Single-mode operation and lithographic tuning across a bandwidth of (cid:2)150 GHz are demonstrated.
关键词： quantum-cascade lasers,surface-emitting,plasmonic,phase-locking,edge-emitting,terahertz
更新于2025-09-19 17:13:59