| 1. |
- Chang, Qingjiang, et al.
(författare)
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A Tunable Broadband Photonic RF Phase Shifter Based on a Silicon Microring Resonator
- 2009
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Ingår i: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1041-1135 .- 1941-0174. ; 21:1-4, s. 60-62
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Tidskriftsartikel (refereegranskat)abstract
- We propose and demonstrate a tunable broadband photonic radio frequency (RF) phase shifter based on a silicon microring resonator. This scheme utilizes the thermal nonlinear effect of the silicon microring to change the electrical phase of the RF signal with a wide tuning range. A prototype of the phase shifter is experimentally demonstrated for a 40-GHz signal with a 0-4.6-rad tuning range.
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| 2. |
- Li, Qiang, et al.
(författare)
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All-optical NRZ-to-AMI conversion using linear filtering effect of silicon microring resonator
- 2009
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Ingår i: Chinese optics letters. - : Shanghai Institute of Optics and Fine Mechanics. - 1671-7694. ; 7:1, s. 12-14
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally demonstrate 10-Cb/s format conversion from non-return-to-zero (NRZ) to alternate-mark-inversion (AMI) using the linear filtering effect of silicon microring resonator. Our discussion and analysis in simulation further show that a 10-Gb/s AMI signal with good quality can be obtained by a resonator with a notch depth larger than 25 dB when the 3-dB bandwidth is 0.4 nm.
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| 3. |
- Li, Qiang, et al.
(författare)
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Asymmetric plasmonic-dielectric coupler with short coupling length, high extinction ratio, and low insertion loss
- 2010
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Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 35:19, s. 3153-3155
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Tidskriftsartikel (refereegranskat)abstract
- Asymmetric directional coupling between a hybrid plasmonic waveguide with subwavelength field confinement and a conventional dielectric waveguide is investigated. The proposed hybrid coupler features short coupling length, high coupling efficiency, high extinction ratio, and low insertion loss; it can also be integrated into a silicon-based platform. This coupler can be potentially adopted for signal routing between plasmonic waveguides and dielectric waveguides in photonic integrated circuits. Furthermore, it can be exploited to efficiently excite hybrid plasmonic modes with conventional dielectric modes.
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| 4. |
- Li, Qiang, et al.
(författare)
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Coupled mode theory analysis of mode-splitting in coupled cavity system
- 2010
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Ingår i: Optics Express. - 1094-4087. ; 18:8, s. 8367-8382
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Tidskriftsartikel (refereegranskat)abstract
- We analyze transmission characteristics of two coupled identical cavities, of either standing-wave (SW) or traveling-wave (TW) type, based on temporal coupled mode theory. Mode splitting is observed for both directly (cavity-cavity) and indirectly (cavity-waveguide-cavity) coupled cavity systems. The effects of direct and indirect couplings, if coexisting in one system, can offset each other such that no mode splitting occurs and the original single-cavity resonant frequency is retained. By tuning the configuration of the coupled cavity system, one can obtain different characteristics in transmission spectra, including splitting in transmission, zero transmission, Fano-type transmission, electromagnetically-induced-transparency (EIT)-like transmission, and electromagnetically-induced-absorption (EIA)-like transmission. It is also interesting to notice that a side-coupled SW cavity system performs similarly to an under-coupled TW cavity. The results are useful for the design of cavity-based devices for integration in nanophotonics.
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| 5. |
- Li, Qiang, et al.
(författare)
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Coupled mode theory analysis of mode-splitting in coupled cavity system
- 2010
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Ingår i: Optics Express. - : The Optical Society. - 1094-4087. ; 18:8, s. 8367-8367
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Tidskriftsartikel (refereegranskat)abstract
- We analyze transmission characteristics of two coupled identical cavities, of either standing-wave (SW) or traveling-wave (TW) type, based on temporal coupled mode theory. Mode splitting is observed for both directly (cavity-cavity) and indirectly (cavity-waveguide-cavity) coupled cavity systems. The effects of direct and indirect couplings, if coexisting in one system, can offset each other such that no mode splitting occurs and the original single-cavity resonant frequency is retained. By tuning the configuration of the coupled cavity system, one can obtain different characteristics in transmission spectra, including splitting in transmission, zero transmission, Fano-type transmission, electromagnetically-induced-transparency (EIT)-like transmission, and electromagnetically-induced-absorption (EIA)-like transmission. It is also interesting to notice that a side-coupled SW cavity system performs similarly to an under-coupled TW cavity. The results are useful for the design of cavity-based devices for integration in nanophotonics.
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| 6. |
- Li, Qiang, et al.
(författare)
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Dense wavelength conversion and multicasting in a resonance-split silicon microring
- 2008
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 93:8
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally demonstrate all-optical wavelength conversions in a 10 mu m radius resonance-split silicon microring resonator based on free carrier dispersion effect. The split resonance is caused by the mutual coupling between the two countertraveling modes inside the ring resonator. Dense wavelength conversions are performed at data rates from 500 Mbytes/s to 5 Gbytes/s and a dual-channel wavelength multicasting is realized at a data rate of 1.25 Gbytes/s. The resonance splitting phenomenon opens up opportunities to convert more closely spaced wavelengths, thus effectively increasing the system capacity.
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| 7. |
- Li, Qiang, et al.
(författare)
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Fast light in silicon ring resonator with resonance-splitting
- 2009
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Ingår i: Optics Express. - 1094-4087. ; 17:2, s. 933-940
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Tidskriftsartikel (refereegranskat)abstract
- We report experimental demonstration of fast light in an over-coupled ultra-compact silicon ring resonator with resonance-splitting. Strong mutual-coupling induced by the grating inside the ring leads to split resonances and accompanying large anomalous dispersion, thus providing a new approach to realizing fast light in the over-coupled region of the ring resonator. In the experiment, a maximum pulse advancement of 130 ps with low distortion is achieved for a 1-ns signal pulse in a 10-mu m-radius silicon ring resonator. The observed pulse advancement agrees well with the theoretical calculation based on coupled mode theory.
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| 8. |
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| 9. |
- Li, Qiang, et al.
(författare)
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System Performances of On-Chip Silicon Microring Delay Line for RZ, CSRZ, RZ-DB and RZ-AMI Signals
- 2008
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8724 .- 1558-2213. ; 26:21-24, s. 3744-3751
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Tidskriftsartikel (refereegranskat)abstract
- We theoretically study the group-delay characteristics of a silicon microring resonator based on the coupled mode theory, and experimentally demonstrate error-free operations of an on-chip delay line using a silicon-on-insulator (SOI) microring resonator with a 20-mu m radius. Four signals of different modulation formats are examined at 5 Gb/s, including return-to-zero (RZ), carrier-suppressed return-to-zero (CSRZ), return-to-zero duobinary (RZ-DB), and return-to-zero alternate-mark-inversion (RZ-AMI). Bit error rate (BER) measurements show that the maximal delay times with error-free operations are 80,95, 110, and 65 ps, respectively, corresponding to a fractional group delay of similar to 0.4, similar to 0.5, similar to 0.55, and similar to 0.35. The differences in delay and signal degradations have been investigated based on the signal spectra and pattern dependences. Although the delays are demonstrated in a single ring resonator, the analysis is applicable in slow-light resonance structures such as all-pass filters (APF) and coupled resonator optical waveguides (CROW).
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| 10. |
- Li, Xiaohui, et al.
(författare)
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Sensitive label-free and compact biosensor based on concentric silicon-on-insulator microring resonators
- 2009
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Ingår i: Applied Optics. - 1559-128X .- 2155-3165. ; 48:25, s. F90-F94
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Tidskriftsartikel (refereegranskat)abstract
- We propose an ultracompact parallel label-free biosensor based on concentric silicon-on-insulator microring resonators. Our numerical studies show that the proposed biosensor offers higher sensitivity and a larger detection area than conventional single-ring-based sensors. We analyze the detection sensitivity of the DNA hybridization by immobilizing the probe on top of the double concentric ring resonators and in the ring-ring air gap. For a concentric double-ring system with an area of 27: 646 mu m(2), the bulk detection sensitivity is 683 nm RIU-1. The sensitive uniformity of the system related to the optical field distribution is also studied.
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| 11. |
- Liu, Fangfei, et al.
(författare)
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Compact optical temporal differentiator based on silicon microring resonator
- 2008
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Ingår i: Optics Express. - 1094-4087. ; 16:20, s. 15880-15886
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Tidskriftsartikel (refereegranskat)abstract
- We propose and experimentally demonstrate a temporal differentiator in optical field based on a silicon microring resonator with a radius of 40 mu m. The microring resonator operates near the critical coupling region, and can take the first order derivative of the optical field. It features compact size thus is suitable for integration with silicon-on-insulator (SOI) based optical and electronic devices. The performance of this optical differentiator is tested using signals with typical shapes such as Gaussian, sinusoidal and square-like pulses at data rates of 10 Gb/s and 5 Gb/s.
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| 12. |
- Liu, Fangfei, et al.
(författare)
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Optically Tunable Delay Line in Silicon Microring Resonator Based on Thermal Nonlinear Effect
- 2008
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - 1077-260X .- 1558-4542. ; 14:3, s. 706-712
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally demonstrate optically tunable delay fine in a silicon microring resonator with a 20-mu m radius. The delay-tuning mechanism is based on the red shift of the resonance induced by thermal nonlinear effect. We investigate the delay performance of three modulation formats-non-return-to-zero (NRZ), return-to-zero (RZ), and differential phase-shift keying (DPSK) signals at different data rates. Tunable delay is achieved by controlling the power of the continuous-wave (CW) pump with very low tuning threshold, which could be used in microring-resonator-based slow-light structure.
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| 13. |
- Lu, Yuanyuan, et al.
(författare)
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All-optical format conversions from NRZ to BPSK and QPSK based on nonlinear responses in silicon microring resonators
- 2007
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Ingår i: Optics Express. - 1094-4087. ; 15:21, s. 14275-14282
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Tidskriftsartikel (refereegranskat)abstract
- We propose and numerically verify a novel scheme of all-optical format conversion from non-return-to-zero (NRZ) to binary phase-shift-keying (BPSK) at 160 Gb/s using cascaded microring resonators (CMRR) on a single silicon chip. The conversion is based on large phase shift and flattened intensity-response characteristics in the CMRR. A continuous-wave light experiences different phase shifts controlled by the power of an input NRZ signal with an similar to 8.8-dB extinction ratio, while maintaining approximately the constant intensity. All-optical format conversion from NRZ to quadrature phase-shift-keying (QPSK) is also demonstrated based on parallel NRZ/BPSK converters in a Mach-Zehnder interferometer structure.
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| 14. |
- Qiu, Min, et al.
(författare)
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Silicon micro-cavities and their system applications
- 2009
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Ingår i: PHOTONICS PACKAGING, INTEGRATION, AND INTERCONNECTS IX. - : SPIE. - 9780819474674
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Konferensbidrag (refereegranskat)abstract
- We experimentally demonstrate resonance-splitting and enhanced notch as a result of the mutual mode coupling in silicon ring resonator. Dense wavelength conversions, wavelength multicasting and optical up-converter are demonstrated in the split silicon ring resonator. A temporal differentiator and format conversion from NRZ to AMI are demonstrated utilizing the filtering effect of ring resonator. Photonic phase shifter and delay line are demonstrated utilizing the phase shift of ring resonator.
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| 15. |
- Wang, Tao, et al.
(författare)
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Modeling of quasi-grating sidewall corrugation in SOI microring add-drop filters
- 2009
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Ingår i: Optics Communications. - : Elsevier BV. - 0030-4018 .- 1873-0310. ; 282:17, s. 3464-3467
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Tidskriftsartikel (refereegranskat)abstract
- We build a model to study the sidewall corrugation of fabricated silicon microrings and investigate its impact on the spectral response of the resonator system. From the scanning electron microscope images, the sidewall corrugation can be engineered into certain periodicity and characterized into a group of rectangular gratings, or quasi-gratings, which in turn generate mutual mode coupling between the forward- and backward-propagating modes in the ring and lead to resonance splitting. We find that the reflectivity of the quasi-gratings is proportional to the mutual coupling strength and the resonance splitting only occurs at the resonances where high reflectivity takes place. The model agrees well with the experimental measurements and provides some guideline in applying mutual mode coupling for various functions in the field of optics.
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| 16. |
- Wang, Tao, et al.
(författare)
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Pulse Delay and Advancement in SOI Microring Resonators With Mutual Mode Coupling
- 2009
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8724 .- 1558-2213. ; 27:21, s. 4734-4743
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we experimentally demonstrate continuously tunable pulse propagation in SOI microring resonators with mutual mode coupling, which is induced by nanosized gratings along the ring sidewalls. In the presence of the mutual mode coupling, dispersion-induced group delay is investigated in single-waveguide and double-waveguide coupled single-ring resonators, respectively. In particular, pulse propagation in the drop channel of a double-waveguide coupled resonator is observed and exhibits continuously tunable delay and advancement features in the experiment. Delayed pulses are also obtained at the reflection port of a single-waveguide coupled resonator due to the existence of backward whispering gallery mode (WGM).
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| 17. |
- Zhang, Ziyang, et al.
(författare)
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Wavelength Conversion in a Silicon Mode-split Micro-ring Resonator with 1G Data Rate
- 2008
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Konferensbidrag (refereegranskat)abstract
- We experimentally demonstrate the wavelength conversion based on free carrier dispersion effect induced by non-linear absorption in a silicon micro-ring resonator. The pump and signal wavelengths are set by the split resonances spaced by 0.4 nm induced by deformation in the coupling region. The results of 500 Mbps and 1Gbps are presented.
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