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Metamaterial Antenna on Electro-Optic Modulator for Wireless Terra-Hertz Detection Through Radio-Over-Fibre Technology
摘要： We propose a new metamaterial antenna on electro-optic (EO) modulator for wireless terra-hertz detection through radio-over-fibre (ROF) technology. By wireless terra-hertz signal irradiation to the proposed device, strong terra-hertz electric field can be induced on the electric-LC metamaterial resonator. The induced terra-hertz electric field can be used for optical modulation through EO effects when a light-wave propagates into an optical waveguide located under the capacitive gap which the strongest induced terra-hertz electric field. Analysis of optical modulation is presented in details for operational frequency of 0.1 THz. The device fabrication process and the results of its measured characteristics are also reported.
关键词： electro-optic modulator,metamaterial antenna,radio-over-fibre,terra-hertz
更新于2025-09-12 10:27:22
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Pulse shaping by a frequency filtering of a sawtooth phase-modulated cw laser
摘要： The spectrum of a cw field the phase of which experiences a periodic sawtooth modulation is analyzed. Two types of the sawtooth phase modulation are considered. One is created by combining many harmonics of the fundamental frequency. The second is produced by an electro-optic modulator fed by the relaxation oscillator, which generates a voltage slowly rising during charging of the energy storage device and dropping fast due to discharge by a short circuit. It is proposed to filter out the main spectral component of the sawtooth phase-modulated field. This filtering produces short pulses from the phase-modulated cw field. The duty cycle of this train is equal to the modulation period, while duration of the pulses depends on the rate of the phase drop. In the case of harmonics, this duration is 4N + 2 shorter than the period of the fundamental frequency, where N is the number of the harmonics. In the case of the charge and discharge, duration of the pulses is close to TD/2, where TD is a drop time of the phase in the discharge period. Depending on the modulation frequency, the proposed method is capable to produce pulses with duration ranging from nanoseconds to a fraction of a picosecond.
关键词： relaxation oscillator,electro-optic modulator,frequency filtering,sawtooth phase modulation,pulse shaping
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Bi-Junction Carrier Depletion Type Electro-Optic Phase-Shifters
摘要： Silicon photonic integrated circuits (PICs) combine dense optical system integration with industrial scalability by adopting well-established CMOS fabrication processes. An electro-optic phaseshifter (EOP) represents a basic building unit of several PICs applications, including datacom optical switches, PIC-FPGAs, and beam steering. In-situ resistive-heaters in close vicinity of waveguides, or free-carrier injection/depletion in doped junctions, are common methods to build EOPs. Literature reports thermal shifters consuming 24.7 mW to achieve DC large signal π-phaseshift, power consumption of injection PIN implementations and depletion PN modulators of 10 mW and ≈ 0 mW respectively. A thermal EOP naturally avoids carrier-induced optical insertion losses (IL), in contrast to a PIN/PN modulator. Thus, thermal and PIN/PN methods trade-off IL with electrical power rather than minimizing both. An EOP of low optical losses and low electrical power is highly desired in large-signal, and low-speed applications.
关键词： electro-optic phaseshifter,datacom optical switches,PIC-FPGAs,beam steering,CMOS fabrication,Silicon photonic integrated circuits
更新于2025-09-11 14:15:04
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Optical Scheme of Obtaining Highest Transmission Factor in Case of KDP Based Electro-Optic Crystal by the Adjustment of Suitable Biasing Voltage and Number of Feedback Passing
摘要： The electro-optic effect becomes prominent when an electric field is applied across the optic axis of a dielectric material inducing the changes in refractive indices of the medium. Kerr and Pockels cells are massively used as optical switches because of their nonlinear electro-optic character. Potassium di-hydrogen Phosphate (KDP) crystal is a very good electro-optic Pockels material as well as has a good switching behavior in optical and opto-electronic domain. The principle of this electro optic effect can be successfully used to develop optical switch based information processing devices. Transmission co- efficient of the polarized light beam have been modulated in a new way by introducing a multi passing scheme across a electro-optic material. Here transmission co-efficient plays a vital role to examine how much output intensity changes for developing feedback one by one in ascending order. In this paper a novel study for the sizable increase of transmission co-efficient of a KDP crystal for a fixed biasing voltage is reported adopting proper feedback mechanism of light. This paper we also observe an theoretical basis for achieving unit transmission coefficient which minimum amount of voltage require for adopting comparatively many large number of feedback.
关键词： electro-optic effect,amplitude modulation,KDP crystal,transmission co-efficient
更新于2025-09-11 14:15:04
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Fluorinated polycarbonate photoresists with adjustable double bond density for electro-optic switch applications by directly written method
摘要： A series of fluorinated polycarbonates (AF-3OH-PC MAs) terminated by different proportions of acrylate group were synthesized and directly used as photoresist materials. The materials can directly form a cross-linked film under UV light and initiator conditions without the addition of small molecular crosslinkers. The thermal stability (Td up to 416 ?C), the absorption at 1550 nm is almost zero and electro-optical stabilities ( after 80 °C for 200 h, the r33 remains 91% of the initial value) are significantly improved since the small molecular crosslinkers were not added. The propagation and insertion loss of the device were measured by a cut-back method to be only 0.66 dB/cm and 1 dB, respectively. It may be possible to have an enlightening effect on preparing electro-optical switches with better performance.
关键词： Directly Written Method,Electro-optic Switch,Double Bond Density,Photoresists,Fluorinated Polycarbonate
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Using Bessel Beams to Induce Programmable Volume Integrated Optical Circuitry
摘要： Programmable waveguides scalable into highly integrated photonic circuits are key ingredients to the development of innovative optical technology in various rapidly growing fields, including linear quantum computation and optical information processing. At present, no scalable optical writing technique based solely on linear waves has been demonstrated in a full macroscopic volume and circuit fabrication involves a step-by-step printing that becomes increasingly cumbersome as design complexity grows. We demonstrate a scalable method to optically induce waveguides deep in a volume using Bessel beams. The method is used to fabricate waveguides in increasingly complex geometries, integrated multi-port splitters and miniaturized functional electro-optic gates. Our experiments are performed in paraelectric potassium-lithium-tantalate-niobate (KLTN) where writing occurs through photogenerated space-charge while guiding and electro-optic functionality are supported by the quadratic electro-optic effect. In Fig. 1 we demonstrate the use of Bessel Beam (BB) waveguide writing to achieve 1×2, 1×3, and 1×4 splitters launching multiple angled BBs during the fabrication stage. The BBs are rendered mutually incoherent using a specific SLM time sequenced mask that turns on one BB at a time. This demonstrates how fabrication of complex circuitry can also be achieved in a single illumination stage without having to mechanically shift and move the sample, as instead is required in direct writing scanning techniques.
关键词： Bessel beams,optical information processing,programmable waveguides,electro-optic gates,photonic circuits
更新于2025-09-11 14:15:04
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Design of Linear Block Code Encoder and Decoder Using Electro-optical and All-optical Units
摘要： In this paper novel designs for linear block code encoder and decoder using optical techniques have been proposed. The structures are designed and simulated using lithium niobate based Mach–Zehnder Interferometer (LN-MZI) and nonlinear material MEH-PPV [poly (2-methoxy-5-(28-ethylhexyloxy)-PPV)] (plasmonic) based MZI (P-MZI). The proposed LN-MZI designs offer attractive parameters such as high extinction ratio (> 35 dB) and low insertion loss (< 0.095 dB), while the proposed P-MZI designs possess a compact structure (3,020–12,375 μm2). An analytical comparison between the two design methodologies and other earlier proposed designs is presented. Each design is presented with a verified mathematical structure. Other performance parameters like contrast ratio and amplitude modulation have also been computed for the presented designs.
关键词： electro-optic,Pockel effect,Kerr effect,error detection,syndrome bits,plasmonic,Mach–Zehnder interferometer,lithium niobate,parity,linear block code
更新于2025-09-11 14:15:04
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[IEEE 2019 International Topical Meeting on Microwave Photonics (MWP) - Ottawa, ON, Canada (2019.10.7-2019.10.10)] 2019 International Topical Meeting on Microwave Photonics (MWP) - Analysis of RF Photonic Link Linearization Using Truncated Fourier Series
摘要： This paper analyzes analog electro-optic modulator linearization techniques employing modulation of multiple distinct carriers with differing modulation efficiencies. We describe a general framework for calculating intermodulation distortion for this type of composite modulation approach. The problem of compensation of nonlinear distortions above 3rd order in electro-optic links to optimize spur free dynamic range is formulated using truncated Fourier series, where the choice of RF photonic link parameters is shown to be equivalent to a corresponding window function applied to the truncated Fourier series representation of a desired transfer function.
关键词： intermodulation distortion,Electro-optic modulation,modeling
更新于2025-09-11 14:15:04
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An Integrated Photonic Electric-Field Sensor Utilizing a 1 × 2 YBB Mach-Zehnder Interferometric Modulator with a Titanium-Diffused Lithium Niobate Waveguide and a Dipole Patch Antenna
摘要： We studied photonic electric-?eld sensors using a 1 × 2 YBB-MZI modulator composed of two complementary outputs and a 3 dB directional coupler based on the electro-optic e?ect and titanium di?used lithium–niobate optical waveguides. The measured DC switching voltage and extinction ratio at the wavelength 1.3 μm were ~16.6 V and ~14.7 dB, respectively. The minimum detectable ?elds were ~1.12 V/m and ~3.3 V/m, corresponding to the ~22 dB and ~18 dB dynamic ranges of ~10 MHz and 50 MHz, respectively, for an rf power of 20 dBm. The sensor shows an almost linear response to the applied electric-?eld strength within the range of 0.29 V/m to 29.8 V/m.
关键词： titanium di?used optical channel waveguide,lithium–niobate electro-optic e?ect,photonic electric-?eld sensor,Y-fed balanced-bridge Mach-Zehnder interferometer (YBB-MZI)
更新于2025-09-11 14:15:04
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Design and Optimization of Proton Exchanged Integrated Electro-Optic Modulators in X-Cut Lithium Niobate Thin Film
摘要： In this study, we designed, simulated, and optimized proton exchanged integrated Mach-Zehnder modulators in a 0.5-μm-thick x-cut lithium niobate thin film. The single-mode conditions, the mode distributions, and the optical power distribution of the lithium niobate channel waveguides are discussed and compared in this study. The design parameters of the Y-branch and the separation distances between the electrodes were optimized. The relationship between the half-wave voltage length production of the electro-optic modulators and the thickness of the proton exchanged region was studied.
关键词： Mach-Zehnder,electro-optic modulator,integrated optics devices,proton exchange,lithium niobate thin film
更新于2025-09-11 14:15:04