- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Broadband polarization-insensitive amplitude and phase modulators based on graphene-covered buried and ridge silicon waveguides
摘要： In this paper, four easy-to-fabricate graphene-based Si waveguide modulators are presented to overcome the strong polarization dependency of graphene-based modulators. The modulation features of two newly proposed structures, i.e. two graphene-based buried silicon waveguides in addition to two standard ridge silicon waveguides at the telecommunication wavelength of are studied. The results show that for certain widths of each waveguide (the height is constant), the amplitude and phase modulations clearly become polarization-insensitive. The amplitude modulation depths for both the TE and TM modes are equal for these optimized waveguides with the precision of . Moreover, in the proposed modulators, the maximum variations of the real parts of the effective mode indices (EMI) for both the TE and TM modes coincide with each other with an excellent precision ( . This precision value is much smaller than the standard criterion value for confirming a polarization-insensitive phase modulation. For proposed structures, the average modulation depth (MD) and maximum variation of the real parts of EMI are about and respectively. Thus, it means to clearly imply small footprints for both amplitude and phase modulations. Furthermore, the performances of all the structures are studied for all optical telecommunication wavelengths. Even without making any changes to the structures designed at at appropriate wavelength intervals, the structures exhibit polarization-insensitive behaviors.
关键词： Graphene,Polarization-insensitive,Optical modulator,Buried waveguide,Ridge waveguide
更新于2025-09-23 15:21:01
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[IEEE 2019 International Applied Computational Electromagnetics Society Symposium - China (ACES) - Nanjing, China (2019.8.8-2019.8.11)] 2019 International Applied Computational Electromagnetics Society Symposium - China (ACES) - Double-Ridge Waveguide Mode Analysis based on FDTD-SVD Method
摘要： In this paper,hybrid finite-difference time-domain method(FDTD) and singular value decomposition(SVD),denoted by FDTD-SVD,is applied to analyze the double-ridge waveguide dominant mode. Double-ridge waveguide (WRD) without fillets and WRD with small fillets are analyzed.The simulation results show WRD without fillets can achieve a single-mode operation of 10TE from 35GHz to 112 GHz. For WRD with small fillets, its single-mode operation frequency band is 35-116GHz.These results are almost consistent with the detailed parametric study result(38-120GHz)based on Ansys HFSS, which proves that the FDTD-SVD method is simple and more effective. In addition, the transmission performance of WRD can be improved by adding fillets and enlarging the radius of fillets.
关键词： mode analysis,singular value decomposition(SVD),finite-difference time-domain method(FDTD),double-ridge waveguide(WRD)
更新于2025-09-23 15:21:01
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Frequency Scanning Single-Ridge Serpentine Dual-Slot-Waveguide Array Antenna
摘要： This paper presents a novel one-dimensional (1D) frequency scanning dual-slot-waveguide array antenna with versatile advantages such as large scan volume, high frequency sensitivity, low cross-polarization and low sidelobe. Electromagnetic waves radiate through the leaky-wave dual slots, machined on the side chambers of the single-ridge serpentine waveguide. By properly designing the serpentine waveguide, which plays the role of delay line, such 1D frequency scanning array antenna can achieve 39? scanning over a frequency range from 9.7 GHz to 10.3 GHz, and high frequency sensitivity of 65?/GHz. The dual slots with all the adjacent monomers inclined in same direction are designed to acquire low cross-polarization and avoid high-order mode radiation. The cross-polarization is 45 dB lower than the corresponding co-polarization over the whole working band. Taylor aperture distribution is employed to achieve a low sidelobe (?21 dB). The nonresonance VSWR is below 1.2, and meanwhile the resonance VSWR remains a low level, around 2.5. Furthermore, our proposed 1D array as a building block can compose a novel 2D electric scanning array, with frequency scanning in one dimension and phase scanning in the orthogonal dimension. A 2D array consisting of three waveguide elements is simulated to predict the phase scanning performance, and the results indicate that a 120? scanning performance can be obtained. At last, a 1D serpentine dual-slot-waveguide array antenna is fabricated, whose measurements show good agreement with simulations.
关键词： frequency scanning,Single-ridge waveguide,dual slots,phase scanning
更新于2025-09-23 15:21:01
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[IEEE 2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR) - Xiamen, China (2019.11.26-2019.11.29)] 2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR) - A Ku-band Broadband Single-Ridge Waveguide Slot Antenna Array for UAV SAR Application
摘要： a Ku-band broadband waveguide wide side longitudinal slot antenna array for unmanned aerial vehicle (UAV) SAR application is designed. A single-ridge is employed to reduce the sectional size of the waveguide, and to achieve wide scanning ability. The bandwidth of the antenna is expanded by the single-ridge and subarea feeding of the slots. The active admittance of the waveguide slot is extracted based on the simulation using the HFSS software, in order to determine the size parameters of the waveguide slots. The simulation mode is built and the size parameters of the waveguide slots are modified and optimized by the aperture distribution re-deducing method. This design method has high efficiency and high veracity. An antenna array of 72 waveguide slot antenna lines is designed and manufactured. The measured results show that the relative bandwidth of VSWR smaller than 2 is 15%. The measured patterns show that the side lobe is smaller than -21.5dB, the cross polarization is better than -40dB, and the scanning angle is ±60° in azimuth direction. This waveguide slot antenna array has many advantages such as wide band, wide scanning, low side lobe and compact structure, and is suitable for UAV SAR application.
关键词： phased array antenna,single-ridge waveguide,waveguide slot antenna,broadband
更新于2025-09-19 17:13:59
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - A Quantization Scheme by Slicing Supercontinuum Spectrum in an All-Normal Dispersion Silicon Nitride Ridge Waveguide
摘要： In this paper, we propose an all normal dispersion silicon nitride waveguide for optical quantization. The results show that a 6-bit quantization resolution is successfully achieved with an effective number of bit of 5.978 bit.
关键词： ridge waveguide,supercontinuum generation,spectral quantization
更新于2025-09-16 10:30:52
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[IEEE 2019 8th International Symposium on Next Generation Electronics (ISNE) - Zhengzhou, China (2019.10.9-2019.10.10)] 2019 8th International Symposium on Next Generation Electronics (ISNE) - Compact Dual-Mode Ridge Waveguide Dual-Band Filter
摘要： A novel dual-mode ridge waveguide structure is proposed to design dual-band bandpass filter in this paper. This new configuration achieves to realize two orthogonal resonant modes which allows for independent control of the two resonant frequencies. In addition, a transmission zero is introduced in the guard-bands improving the filter selectivity, while keeping a simple and compact inline topology.
关键词： ridge waveguide,transmission zero,resonator,Dual-mode,high isolation
更新于2025-09-16 10:30:52
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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) - Highly Efficient Ultra-Broadband Entangled Photon-Pair Generation using a Chirped PPSLT Ridge Waveguide
摘要： As some of the most promising quantum applications such as high resolution quantum optical coherence tomography (QOCT) with dispersion cancellation as well as quantum key distribution require frequency entanglement. Therefore, frequency entanglement light sources are an essential importance for implement of many quantum optical applications. So Far, the most prominent method used for the entangled photon pair generation is spontaneous parametric down-conversion (SPDC) in nonlinear crystals. Recently, with adopting chirp quasi-phase matching (QPM) PPSLT (periodically poled stoichiometric lithium tantalate) has been used as source of entangled photons with large bandwidth. However, improving the overall system ef?ciency is still remain challenging. One realistic approach is improving the generation ef?ciency of the entanglement source, we developed a source for highly ef?cient frequency entangled photon pairs generation utilizing type-0 PPSLT by adopting chirp QPM technology together with ridge waveguide structure. In experiments, we use 10 mm long waveguides with chirp rate of 0%, 3% and 6.7%. After coupling 405 nm CW pump light into a waveguide we fed the collinearly emitted photons into a single mode ?ber then observed its spectrum with a spectroscope. During experiments, temperature of all waveguides were set to 70.8?C with an accuracy of 0.1?C to ensure the degenerated phase matching condition of fundamental modes for signal, idler and pump lights is met in our multi-mode waveguides. As results are shown in Fig.1 (a), we observed a ～ 20 nm bandwidth sinc function-like spectrum emitted from the 0% chirp waveguide (blue dots), moreover, with increasing device chirp rate we also managed to obtain the broadening of spectra. The measured result of a 3% chirp rate device shows a spectrum with ～ 240 nm bandwidth, as well as ～ 340 nm bandwidth (orange dots) spectrum generated via the 6.7% one. In order to properly evaluate the generation ef?ciency of collinearly emitted photons we separate them with a 50:50 ?ber beam splitter, since signal and idler photons share the same spatial mode (fundamental mode of ridge waveguide) and identical in both frequency and polarization degree of freedom. Fig.1 (b) is the power dependency measurement results measured with a 3% chirp rate waveguide, signal and idler counts are the recorded counting rate of events from two SSPDs. We estimate the generation ef?ciency as 3.2×106 pairs/s·μW. This result appears 1000 times higher compared to our previous result (2×103 pairs/s·μW) observed using a chirped bulk QPM device.
关键词： ridge waveguide structure,frequency entanglement,quantum optical coherence tomography,quantum key distribution,PPSLT,chirp quasi-phase matching,spontaneous parametric down-conversion
更新于2025-09-16 10:30:52
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[IEEE 2019 49th European Microwave Conference (EuMC) - Paris, France (2019.10.1-2019.10.3)] 2019 49th European Microwave Conference (EuMC) - Equivalent calculation method for low-pressure discharge threshold of ridge waveguide filter
摘要： Based on the theory of high frequency breakdown calculation, this paper studies the calculation method of ionization breakdown threshold of ridge waveguide filter under the action of RF field. By comparing with the experimental measurements, the accuracy of the theoretical analysis method of the ionization breakdown of the typical ridge waveguide filter structure is proved. At the same time, the low-pressure ionization breakdown thresholds of different air pressures, structural gaps and working frequencies were calculated, and the action law of each influencing factor was analyzed, and the relationship between breakdown position and electric field distribution was clarified.
关键词： threshold calculation,Ridge waveguide filter,low air pressure discharge,influence law
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE/MTT-S International Microwave Symposium - IMS 2019 - Boston, MA, USA (2019.6.2-2019.6.7)] 2019 IEEE MTT-S International Microwave Symposium (IMS) - Contra-Directional 3dB 90° Hybrid Coupler in Ridge Waveguides Using Even and Odd TE Modes
摘要： A novel compact wide-band contra-directional single conductor ridge waveguide coupler is presented. It exhibits 50% fractional bandwidth with equal power split between the through and coupled ports while occupying a very compact volume. The design can be exploited in versatile applications, such as beam forming, or high-power combiners. The methodology to design the coupler is presented. It starts with designing the coupling section in a modified double ridge waveguide that supports two independent propagating TE modes. Proper choice of the cross section allows the designer to achieve the required impedance levels for tight coupling values, not common for standard waveguide contra-directional couplers. An S-band proof of concept prototype was synthesized, simulated, fabricated and tested demonstrating excellent measured results without any tuning.
关键词： beam forming,backward coupling,Ridge waveguide,power amplifiers
更新于2025-09-12 10:27:22
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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) - Determination of the Residual Amplified Spontaneous Emission in Single-Mode Semiconductor Optical Amplifiers
摘要： The Master-Oscillator-Power-Amplifier (MOPA) is a laser light source best suited to provide high power, stable frequency, and narrow linewidth emission. In state-of-the-art MOPA systems, semiconductor optical amplifiers (SOAs) with single-mode lateral waveguides provide a compromise between the demands for high power on one side and excellent beam quality and small astigmatism of the optical mode on the other. The amplified spontaneous emission (ASE) in SOAs remains a limiting factor for the deployment of the MOPA systems in quantum technology applications. The presence of ASE reduces the carrier density and hence the device efficiency, increases the noise in the output signal, and adds incoherent background radiation that is critical, for example, for atom interferometry applications. It is therefore important to understand the dependence of the ASE on the design and operating conditions of an SOA in detail in order to develop SOAs optimized for applications that require spectrally very pure radiation. In this work, the coherent and the residual ASE power of ridge waveguide (RW) SOAs are experimentally determined as a function of the seed power (optical power at the input of the SOA) and the SOA current. The experiment provides essential information about the suppression of the ASE background and the saturation behaviour of the optical amplifier. The measurement setup is depicted in Fig. 1 (a). The seed laser (ECDL, TE-polarized at 871 nm) is operated far above its threshold to avoid amplification of the spontaneous emission of the seed laser by the SOA. An acousto-optic modulator (AOM) is used to set the seed power. The laser beam is then fed into the 6 mm long SOA. A non-polarizing beam splitter (BS) cube divides the output beam into two parts. One part (reference beam) is detected using a power meter (PM). The spectrum of the second part is recorded using an Advantest Q8347 optical spectrum analyser (OSA). The measured data is analysed using the correlation between optical power measured with the power meter and the optical spectrum. The ASE power is reconstructed from the remaining ASE (fitted) spectrum after removing the coherent part. Fig. 1(b) shows the measured total output, ASE and coherent powers retrieved from the spectrum as a function of the seed power. The measured quantities in Fig. 1(b) are compared to theoretical values which are calculated using a SOA model similarly as described in [2]. The carrier-density dependent spectra of the gain and the spontaneous emission are obtained from a microscopic model taking into account the waveguide structure [3]. The comparison shows good qualitative agreement between theory and measurement. We show how the experimental findings are used to validate and calibrate the model and how the model can be applied to compare the performance (coherent power, ASE background, saturation behaviour) of SOAs at different seed powers, injection current setting, different lengths or different lateral geometries.
关键词： ridge waveguide SOAs,semiconductor optical amplifiers,Master-Oscillator-Power-Amplifier,quantum technology applications,amplified spontaneous emission
更新于2025-09-12 10:27:22