Огляд наукової інформації 30. 10 .201 7

1. Огляд наукової інформації30.10.2017 Доповідач: І.В. Трубаров

2. 1. Microresonator-based solitons for massivelyparallel coherent optical communicationsPablo Marin-Palomo, Juned N. Kemal, Maxim Karpov, Arne Kordts, Joerg Pfeifle, Martin H. P. Pfeiffer, Philipp Trocha,Stefan Wolf, Victor Brasch, Miles H. Anderson, Ralf Rosenberger, Wolfgang Freude, Tobias J. Kippenberg & Christian KoosNature, June 2017, Vol. 546, No. 7657 Solitons are waveforms that preserve their shape while propagating, as a result of a balance of dispersion and nonlinearity. Soliton based data transmission schemes were investigated in the 1980s and showed promise as a way of overcoming the limitations imposed by dispersion of optical fibres. Here we show that solitons could make a comeback in optical communications, not as a competitor but as a key element of massively parallel wavelength-division multiplexing. Instead of encoding data on the soliton pulse train itself, we use continuous-wave tones of the associated frequency comb as carriers for communication. Dissipative Kerr solitons (DKSs) (solitons that rely on a double balance of parametric gain and cavity loss, as well as dispersion and nonlinearity) are generated as continuously circulating pulses in an integrated silicon nitride microresonator5 via four-photon interactions mediated by the Kerr nonlinearity, leading to low-noise, spectrally smooth, broadband optical frequency combs.

3. 1. Microresonator-based solitons for massivelyparallel coherent optical communicationsPablo Marin-Palomo, Juned N. Kemal, Maxim Karpov, Arne Kordts, Joerg Pfeifle, Martin H. P. Pfeiffer, Philipp Trocha,Stefan Wolf, Victor Brasch, Miles H. Anderson, Ralf Rosenberger, Wolfgang Freude, Tobias J. Kippenberg & Christian Koos

4. 1. Microresonator-based solitons for massivelyparallel coherent optical communicationsPablo Marin-Palomo, Juned N. Kemal, Maxim Karpov, Arne Kordts, Joerg Pfeifle, Martin H. P. Pfeiffer, Philipp Trocha,Stefan Wolf, Victor Brasch, Miles H. Anderson, Ralf Rosenberger, Wolfgang Freude, Tobias J. Kippenberg & Christian Koos

5. 1. Microresonator-based solitons for massivelyparallel coherent optical communicationsPablo Marin-Palomo, Juned N. Kemal, Maxim Karpov, Arne Kordts, Joerg Pfeifle, Martin H. P. Pfeiffer, Philipp Trocha,Stefan Wolf, Victor Brasch, Miles H. Anderson, Ralf Rosenberger, Wolfgang Freude, Tobias J. Kippenberg & Christian Koos

6. 1. Microresonator-based solitons for massivelyparallel coherent optical communicationsPablo Marin-Palomo, Juned N. Kemal, Maxim Karpov, Arne Kordts, Joerg Pfeifle, Martin H. P. Pfeiffer, Philipp Trocha,Stefan Wolf, Victor Brasch, Miles H. Anderson, Ralf Rosenberger, Wolfgang Freude, Tobias J. Kippenberg & Christian Koos

7. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang ShenIEEE Transactions on Microwave Theory and Techniques, July 2017, Vol. 65, No. 7 Circular and elliptical loop resonators are proposed as the unit cell of 3-D frequency-selective structure aiming to reduce the structure thickness. The structure exhibits a pseudoelliptic response by utilizing the coupling between the two quasi-TEM modes, which are concentrated in air and substrate regions of the unit cell. Using elliptical loop with stepped-impedance resonator (SIR), the thickness of the structure can be reduced by 80% compared to previous structures. A comparison between the response of the structure employing the microstrip line as the resonator and the structure using the proposed loop resonators is performed. Three prototypes are designed, fabricated, and tested. The first structure is designed to have a dual-band bandstop response using two half-circular loops with end via holes; it has center frequencies at 10 and 14.3 GHz with −3 dB fractional bandwidths of 6.7% and 6.6%, respectively. A half-elliptical loop with SIR is employed in the second structure to achieve more thickness reduction. The third structure is designed to exhibit a dual-polarized bandstop response. Stable frequency response under various angles of incidence is obtained.

8. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang Shen

9. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang Shen

10. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang Shen

11. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang Shen

12. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang Shen

13. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang Shen

14. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang Shen

15. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang Shen

16. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang Shen

17. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang Shen

18. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang Shen

19. 2. Thin Bandstop Frequency-Selective StructuresBased on Loop ResonatorAhmed Abdelmottaleb Omar and Zhongxiang Shen

20. 3. Parametric Modeling of Microwave ComponentsUsing Adjoint Neural Networks and Pole-ResidueTransfer Functions With EM Sensitivity AnalysisFeng Feng, Venu-Madhav-Reddy Gongal-Reddy, Chao Zhang, Jianguo Ma and Qi-Jun ZhangIEEE Transactions on Microwave Theory and Techniques, June 2017, Vol. 65, No. 6 Lately, there has been a growing interest in the ridge gap waveguide (RGW) technology as a guiding structure for high-frequency applications. Low loss and low dispersion are two major advantages of the RGW. On the other hand, the major disadvantage of this technology is the difficulty in fabrication as it requires fabrication with high precision, in particular for high-frequency applications. The operating bandwidth of the RGW is controlled by the stopband of the texture surrounding the ridge. A study to enhance the bandwidth is introduced for possible utilization of the full band achievable by the unit cell in the presence of the ridge. Modifications of the cell filling shape and the ridge structure are carried out to enhance the RGW bandwidth. We have introduced a new RGW based on mixed fabrication technology. The proposed architecture introduces adaptive and straightforward structure with improved bandwidth while keeping the characteristic impedance at the same value. The proposed structure is fabricated and measured. The measured scattering parameters are in excellent agreement with the simulated ones.

21. 3. Parametric Modeling of Microwave ComponentsUsing Adjoint Neural Networks and Pole-ResidueTransfer Functions With EM Sensitivity AnalysisFeng Feng, Venu-Madhav-Reddy Gongal-Reddy, Chao Zhang, Jianguo Ma and Qi-Jun Zhang

22. 3. Parametric Modeling of Microwave ComponentsUsing Adjoint Neural Networks and Pole-ResidueTransfer Functions With EM Sensitivity AnalysisFeng Feng, Venu-Madhav-Reddy Gongal-Reddy, Chao Zhang, Jianguo Ma and Qi-Jun Zhang

23. 3. Parametric Modeling of Microwave ComponentsUsing Adjoint Neural Networks and Pole-ResidueTransfer Functions With EM Sensitivity AnalysisFeng Feng, Venu-Madhav-Reddy Gongal-Reddy, Chao Zhang, Jianguo Ma and Qi-Jun Zhang

24. 3. Parametric Modeling of Microwave ComponentsUsing Adjoint Neural Networks and Pole-ResidueTransfer Functions With EM Sensitivity AnalysisFeng Feng, Venu-Madhav-Reddy Gongal-Reddy, Chao Zhang, Jianguo Ma and Qi-Jun Zhang

25. 3. Parametric Modeling of Microwave ComponentsUsing Adjoint Neural Networks and Pole-ResidueTransfer Functions With EM Sensitivity AnalysisFeng Feng, Venu-Madhav-Reddy Gongal-Reddy, Chao Zhang, Jianguo Ma and Qi-Jun Zhang