- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Graphene-Incorporated Soft Capacitor for Mechanically-Adjustable Electro-Optic Modulators
摘要： In addition to ultra-high capacity and speed in data management, future communication networks require enhanced performance via system reconfigurability under limited resources. Extremely high-speed operation renders optical data managing devices as excellent candidates to hybridize with current electronic devices; however, they still need tunability for system reconfiguration in an integrated scheme. We demonstrate an efficient electro-optic (EO) modulator that is mechanically tunable on a multiple optical waveguide system functioned with a soft capacitor structure incorporating graphene and poly(methyl methacrylate) (PMMA). The flexible capacitor that generates optical signals by temporal light absorption depending on electrical signals can be mechanically detached and re-attached from and onto a rigid surface of the waveguide. It provides either the on or off state of the modulating operation, and enables switching of the working waveguides following the reconfigured data routes. Quality-controlled graphene mainly provides the EO operation, and PMMA plays an important role as both the flexible dielectric layer in the capacitor and the passivation layer for graphene protection. The modulation effects of the manually prepared graphene-PMMA capacitor mechanically adjusted onto a side-polished optical fiber (D-shaped fiber) are investigated in terms of the extinction ratio (ER) of the transmitting light and the operational bandwidth. We successfully display an ER of the modulator up to 19.8 dB with a voltage control ranging from -50 V to 50 V. Its stable operation is verified with a modulation speed up to 2.5 MHz.
关键词： electro-optic modulator,mechanical tuning,graphene,tunable modulator,soft material
更新于2025-11-28 14:24:03
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Application of MoWS2-rGO/PVA thin film as all-fiber pulse and amplitude modulators in the O-band region
摘要： In this work, a MoWS2-rGO/PVA thin film is fabricated and its applications as in amplitude modulation are demonstrated. Embedded in a praseodymium fluoride fiber laser cavity, the MoWS2-rGO/PVA thin film is able to induce pulsing in the laser output, which operates in the O-band region. As an optical amplitude modulator, the MoWS2-rGO/PVA thin film is capable of achieving a modulation efficiency of 0.17 dB/mW in the O-band region over a pump power range of 46.0 mW to 78.5 mW. C-band and L-band operation is also demonstrated, with modulation efficiencies of 0.30 dB/mW and 0.15 dB/mW, respectively over pump power ranges of 3.51 mW–52.17 mW and 24.4 mW–61.3 mW. This work can be improved by further engineering the composition ratio of the alloy material to enhance the modulation efficiency for both pulsed and amplitude modulations, giving rise to various applications, in particular in bio-medicine and manufacturing.
关键词： Amplitude modulator,MoWS2-rGO/PVA thin film,Pulse modulator,O-band
更新于2025-11-28 14:23:57
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Photonic generation of high-purity 60?GHz millimeter-wave signal requiring only 10?GHz radio frequency local oscillator
摘要： A novel approach to generate 60 GHz millimeter-wave from a 10 GHz radio frequency signal using an integrated nested DD-MZM without optical filter is proposed and demonstrated. The simulation results show that the generated frequency sextupling optical mm-wave has high purity with an OSSR exceeding 29 dB and a RFSSR of 25 dB, which is consistent with the theoretical analysis. Besides, a RoF link model is established to investigate the transmission performance. The eye diagram keeps clear even when the optical mm-wave is transmitted over 60 km and the power penalty is about 0.4 dB after fiber transmission of 50 km.
关键词： Optical fiber communication,Dual-drive Mach–Zehnder modulator (DD-MZM),Optical millimeter-wave generation
更新于2025-09-23 15:23:52
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[Communications in Computer and Information Science] Futuristic Trends in Network and Communication Technologies Volume 958 (First International Conference, FTNCT 2018, Solan, India, February 9–10, 2018, Revised Selected Papers) || Future Perspectives in Elastic Optical Networks
摘要： The new generation Elastic Optical Networks (EONs) based on Orthogonal Frequency Division Multiplexing (OFDM) can accommodate exponentially increasing heterogeneous data traffic efficiently and economically. In EONs, the optimum channel spacing between various subcarriers is very crucial for its efficient performance. The use of Sub-Carrier Multiplexing (SCM) in EONs is visualized as an evolving field. This paper present the evaluation of SCM based EONs for both mathematical and simulative model. The designed SCM-EON network is analytically evaluated for its performance with different modulation techniques (Direct Modulation and External Modulation). The performance of system is also evaluated for amplification using Semiconductor Optical Amplifier (SOA) and Erbium Doped Fiber Amplifier (EDFA). Simulative results show that Optical Phase Modulation (OPM) along with EDFA offers enhanced performance for the proposed model. It has also been observed that OPM is a better technique for SCM and hence it can be deduced that the combination will boost EONs efficiency in handling network resources.
关键词： SCM,Elastic Optical Networks,OFDM,EDFA,OPM,Bandwidth variable-wavelength cross-connects (BV-WXC),Quadrature Amplitude Modulation (QAM),Coherent Optical Orthogonal Frequency Division Multiplexing (CO-OFDM),Mach-Zehnder modulator (MZM)
更新于2025-09-23 15:23:52
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Design and development of a novel level transmitter utilizing lithium niobate (LiNbO3) Mach-Zehnder modulator for hazardous regions
摘要： In the proposed work, a very low-cost transducer and a novel photonic based transmission technique have developed for liquid level measurement. Two copper parallel plates are used to measure the liquid level in the sensing tube. For transmission of the measured quantity to the remote location, electrical (1–5 V DC), as well as optical technique, has been used. A lithium niobate (LiNbO3) based Mach Zehnder interferometer has been used for the optical transmission. In the proposed method 40GHz, Photline made MXAN-LN-40 light intensity Mach-Zehnder modulator was used. The optical output was analyzed with the help of optical spectrum analyzer (MS9710B) as well as optical meter. Optical transmission was not affected by EMI interference and very advantageous in the inflammable regions. With the help of the proposed method, the sensitivity of 7.02 pF/cm. from the sensor and ?0.236 dBm/cm. from the modulator were achieved. The output of the sensor, signal conditioning, and optically transmitted data has been analyzed experimentally.
关键词： Level transmitter,Optical intensity modulator,Optical spectrum analyzer (OSA),Level sensor,Optical power meter
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE Photonics Conference (IPC) - Reston, VA (2018.9.30-2018.10.4)] 2018 IEEE Photonics Conference (IPC) - 40Gb/s Carrier Depletion-Based Silicon Micro-Ring Modulators
摘要： A high-speed silicon microring modulator based on a titanium-doped silicon rib waveguide has been demonstrated. Small footprint of 26.5 μm × 26.5 μm with low driving voltage of 1.5 V and 22 dB extinction ratio at 20 Gb/s modulation has been achieved. The high-speed performance is attributed to the low capacitance of the device and the efficient plasma dispersion effect in silicon. Moreover, the modulator exhibits a low propagation loss of 2.5 dB/cm and a high modulation efficiency of 1.5 V·cm. The device is fabricated on a silicon-on-insulator (SOI) wafer with a 220 nm top silicon layer and a 2 μm buried oxide layer. The rib waveguide has a width of 500 nm and a height of 220 nm with a slab height of 150 nm. The titanium doping concentration is 1×10^20 cm^{-3}. The modulator is characterized using a lightwave component analyzer and a high-speed photodetector. The 3-dB bandwidth is measured to be 20 GHz. The eye diagrams at 20 Gb/s show clear eye opening with low jitter. The results indicate that the titanium-doped silicon microring modulator is promising for high-speed optical interconnects.
关键词： high-speed modulation,titanium doping,optical interconnects,silicon photonics,microring modulator
更新于2025-09-23 15:23:52
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Optronic High-Resolution SAR Processing with the Capability of Full-Resolution Imaging
摘要： The improvement of synthetic aperture radar (SAR) resolution brings a broader applications but poses a great burden for SAR data processor. Real-time processing becomes a difficulty. Optronic technology has been developed for SAR real-time processing due to its ultrafast processing speed. A novel real-time optronic high-resolution SAR processor is proposed in this paper. It has the capability of full-resolution imaging. Restricted with the data scale of spatial light modulators (SLMs), SAR raw data cannot be all encoded onto the light beams at a time. To solve this, subaperture architecture is introduced in our system scheme. SAR data is optically processed in parallel by multiple optical subaperture processing modules and synthesized into a full-resolution SAR image. The module is implemented by multiple SLMs and lenses, which is innovatively proposed in this paper. The proposed system is applicable to large-scale SAR data processing, and the data scale is easy to extend with implementation of adding identical optical subaperture processing modules. Airborne SAR real data is used in the experiment, and a high-resolution image is also given. The PSLR of the focus results with and without subaperture partition are analyzed, which validate the satisfying image quality of the proposed algorithm.
关键词： high resolution,synthetic aperture radar,spatial light modulator,subaperture,full-resolution imaging,Optronic processing
更新于2025-09-23 15:22:29
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Structural and Functional Consequences of the Weak Binding of Chlorin e6 to Bovine Rhodopsin
摘要： The chlorophyll-derivative chlorin e6 (Ce6) identified in the retinas of deep-sea ocean fish is proposed to play a functional role in red bioluminescence detection. Fluorescence and 1H NMR spectroscopy studies with the bovine dim-light photoreceptor, rhodopsin, indicate that Ce6 weakly binds to it with μM affinity. Absorbance spectra prove that red light sensitivity enhancement is not brought about by a shift in the absorbance maximum of rhodopsin. 19F NMR experiments with samples where 19F labels are either placed at the cytoplasmic binding site or incorporated as fluorinated retinal, indicate that the cytoplasmic domain is highly perturbed by binding, while little to no changes are detected near the retinal. Binding of Ce6 also inhibits G protein activation. Chemical shift changes in 1H,15N NMR spectroscopy of 15N-Trp labeled bovine rhodopsin reveal that Ce6 binding perturbs the entire structure. These results provide experimental evidence that Ce6 is an allosteric modulator of rhodopsin.
关键词： G protein coupled receptor,chlorophyll-derivative,porphyrin,night vision,light activation,photosensitization,bovine rhodopsin,Allosteric modulator
更新于2025-09-23 15:22:29
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The application of SLM in shearography detecting system
摘要： The paper presents a new shearography system which applies a spatial light modulator (SLM). The system can control the shearing amount and direction as well as introduce the phase shift accurately and automatically, making shearographic testing easier and more practical. Shearography has the known advantages for nondestructive test and strain measurements of being fast, full-field, and having high sensitivity. Traditionally, the shearing amount is controlled by adjusting a reflector mechanically. Mechanical adjustment of the reflector is slow, inconvenient and not well suited for in-field NDT practice. For application of phase shift techniques, a piezoelectric transducer (PZT), which is usually used for application of phase shift techniques, introduces random error due to its tendency to be nonlinear. This paper introduces a new shearographic detection system with a spatial light modulator. The spatial light modulator controls the liquid crystal by using a birefringence effect and twisted nematic effect. The spatial light modulator can change the phase of the light and shearing amount accurately and automatically, thus eliminating the nonlinear random error in the phase shift method. Furthermore, this system also improves testing efficiency. In this paper, the fundamental of SLM shearography is presented. The capability of this optical configuration is demonstrated theoretically as well as through experiments.
关键词： Nondestructive detecting,Spatial light modulator,Shearography,Phase series
更新于2025-09-23 15:22:29
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High-resolution refractometry using phase shifting interferometry based on spatial light modulator and vortex probe
摘要： We present a spatial light modulator (SLM) based phase shifting interferometry (PSI) using an optical vortex for sensing the refractive index (RI) of liquids. The vortex phase rotates according to the phase shift introduced by a medium, and its rotation angle quantifies the index of refraction of the sample. An interferometer modified with the SLM is designed to obtain reliable results. We experimentally demonstrate the stability of the SLM-based system by measuring interference and phase fluctuation. Experimental results show that the proposed system keeps the fluctuation small. The vortex probe PSI combined with the SLM-based interferometer enables not only detecting extremely small changes in concentration but also precisely measuring the RI with high resolution of ～10?? refractive index unit.
关键词： Refractive index sensing,Spatial light modulator,Optical vortex,Interferometry
更新于2025-09-23 15:22:29