1、基于AEMD平臺加工的硅光子芯片Silicon photonic chips fabricated in the AEMD center of SJTU11摘要關于AEMD加工平臺高效率(21 nm/mW)納米束熱光可調濾波器低功耗(0.16 mW)納米束2x2熱光開關基于亞波長光柵的高旁瓣抑制比(27dB)帶通濾波器高消光比(30 dB)的偏振分束器超緊湊的偏振分束和旋轉器總結22OutlineAbout AEMD centerHigh-efficiency (19 nm/mW) nanobeam thermo-optic filterLow-power (0.16 mW) nanobeam

2、 2x2 thermo-optic switchSubwavelength-grating bandpass filter with high sidelope suppression (27 dB)High extinction ratio (30 dB) polarization beam splitterUltra-compact polarization beam splitter and rotatorSummary33OutlineAbout AEMD centerHigh-efficiency (19 nm/mW) nanobeam thermo-optic filterLow-

3、power (0.16 mW) nanobeam 2x2 thermo-optic switchSubwavelength-grating bandpass filter with high sidelope suppression (27 dB)High extinction ratio (30 dB) polarization beam splitterUltra-compact polarization beam splitter and rotatorSummary44凈化面積：1510m2(東892m2+西618m2 )配 置：6”半導體級實驗線+3”非硅實驗線+光電實驗室西區凈化室

4、EBL西區光刻區西區光刻區西區濕法區西區薄膜 I 區西區薄膜 II 區聚焦離子束區西區西區氧化擴散區西區廠務灰區東區東區光刻區東區微加工區東區光電器件區設 備：價值7800萬元人 員：25名工程師/行政人員運 行：2014.11.9正式對外運行AEMD 公共平臺簡介5 具備亞10nm至微米級圖形加工能力 可加工硅基、玻璃基、聚合物基基底AEMD設備配置狀況6校外單位：59家校外用戶賬號數：77個對外服務合同：102個校外用戶遍布全國：20個城市國內高校：北京大學、清華大學、浙江大學、南京大學、南京航天航空大學、華中科技大學、華東理工大學、西北工大、蘇州大學、西南交大等國內科研機構：中科院技術物

5、理所、微系統所、長春光機所、硅酸鹽所、中電58所、中電38所等國內企業：華為、中興、武漢光訊、美國晟碟科技等AEMD服務的校外用戶77OutlineAbout AEMD centerHigh-efficiency (19 nm/mW) nanobeam thermo-optic filterLow-power (0.16 mW) nanobeam 2x2 thermo-optic switchSubwavelength-grating bandpass filter with high sidelope suppression (27 dB)High extinction ratio (30

6、dB) polarization beam splitterUltra-compact polarization beam splitter and rotatorSummary8Nanobeam（1-dimensional photonic crystal）：more compact than conventional 2D photonic crystalReflectorReflectorTaperTaperField distributionAdvantage of the nanobeam：ultra-compact mode volume ( 0.2m3)，the smallest

7、 among all known silicon-only devicesAbout Nanobeam9Higher tuning efficiency with a single resonance over a wide band Structures Tuning efficiencySingle resonanceMach-Zehnder interferometer (MZI) 10.29 nm/mWNoSuspended microring 24.8 nm/mWNoPhotonic crystal nanobeam 30.27 nm/mWYes TO filters: state-

8、of-the-artsOur goal:Ref: 1. F. Gan et al., MIT, Photonics in Switching, TuB3.3, 2007 2. P. Dong et al., Kotura, Optics Express, 18(19), 20298, 2010 3. J. Zhang et al., ZJU, Optics Express, 25 (11), 12541, 2017Proposed TO nanobeam filter10Ultra-small mode volume Single resonanceHigh tuning efficiency

9、Large tuning rangeSuspended structureHigh tuning efficiencyHeater on slabFast response timeY. Zhang et al. Proc. INEC, pp. 1-2, (2016).Design and simulation11Mode volume: 0.018 mm3Design of Nanobeam cavityThermal distributionSimulated tuning efficiency 30 nm/mWDevice fabrication process12Fabricated

10、in the AEMD platform of Shanghai Jiao Tong UniversitySEM photos of fabricated nanobeam filter1314Vertical coupling and edge coupling setupDevice testing instrumentMeasurement results15Single-resonance tuning range of 34 nm 1.78 mWInter-channel crosstalk -9 dB 34 nm tuningInter-channel crosstalk -15

11、dB 25 nm tuningTuning efficiency 19.32 nm/mWMeasured response times16Measured 10%90% switching times 6 msMore than twenty times faster than those for the suspended MZI and microring devices 1, 2Attributed to that heater is directly placed on the silicon slabRef: 1. P. Dong et al., Kotura, Optics Exp

12、ress, 18(19), 20298, 2010 2. P. Sun et al., Ohio State University, Optics Express, 18(8): 8406, 2010Comparison with previous TO filters17StructuresTuning efficiency (nm/mW)Response time (ms)Single resonanceMach-Zehnder interferometer (MZI) 10.2914No Microring 2 0.99No Adiabatic Resonant Microring 31

13、.81No Suspended microring 44.8170No Suspended MZI 5-141No Photonic crystal nanobeam 60.2713Yes Suspended nanobeam (our device)19.326Yes Ref: 1. F. Gan et al., Photonics in Switching, TuB3.3, 2007 2. P. Dong et al., Optics Express, 18(10), 2010 3. M. Watts et al., CLEO, CPDB10, 2009 4. P. Dong et al.

14、, Optics Express, 18(19), 2010 5. P. Sun et al., Optics Express, 18(8), 20106. J. Zhang et al., Optics Express, 25(11), 20171818OutlineAbout AEMD centerHigh-efficiency (19 nm/mW) nanobeam thermo-optic filterLow-power (0.16 mW) nanobeam 2x2 thermo-optic switchSubwavelength-grating bandpass filter wit

15、h high sidelope suppression (27 dB)High extinction ratio (30 dB) polarization beam splitterUltra-compact polarization beam splitter and rotatorSummary22 silicon optical switch: prior art19Broadband, high reliability, large footprintSmall footprint, narrow bandwidth22 optical switch based on Microrin

16、g resonator (MRR)22 optical switch based on Mach-Zehnder interferometer (MZI)Y. Li et al., Photon. Research, Vol. 3, (2015)Optical switch is a key component for on-chip optical networksInputThroughDropAddInputThroughDropAdd Bar state Cross state2 x 2 optical switching using a nanobeam cavity 20The o

17、peration principle is based on coupled mode theoryA single nanobeam:A standing-wave resonatorUltra-small mode volume ( V = (/2n)3 )Energy distributes equally at each port (25%, 6dB extinction ratio)TypeHeater lengthMZIfew mmMMR2R mNanobeam13 mThroughInAddDropProposed 22 TO nanobeam wavelength switch

18、 21 Nanobeam switchMotivation:Optical switch with small device footprint and low switching powerEnhanced light-matter interactionUltra-small mode volumeEffective TO tuning, Ultra-low switching power HeaterNanobeamHuanying Zhou, et al., Photonics Research, Vol. 5, p 108, (2017)Dual nanobeam cavities

19、with high extinction ratio 22Based on coupled mode theorySingle nanobeam: a maximum of 25% output at each port (-6dB).Dual nanobeams : at |12| = , high efficiency output at drop port.FDTD simulation results:3dB-bandwidth 0.18nmThrough-port ER: 19 dBDrop-port output : 89%|12| = Device design layout23

20、 Layout of our proposed TO nanobeam switch Heater1,2 for wavelength shiftHeater 3 for phase differenceSOI waferE-beam lithography and reactive ion etching (RIE)100-nm-thick Titanium heater2-m-thick Aluminum padDevice Footprint : 150 m x 30 m220nm3m1.5m100nm Cross-section viewFabrication process24Fab

21、ricated in the AEMD lab of Shanghai Jiao Tong UniversityFabricated device25wire bonding to a PCBSEM1mSingle step etched TE grating couplerHuanying Zhou, et al., Photonics Research, Vol. 5, p 108, (2017)Wavelength tuning and switching262x2 nanobeam switchWavelength red-shift: 1.7nmTuning efficiency :

22、 1.23 nm/mW Switching power : 0.16mW with a 3dB-bandwidth wavelength shift. Huanying Zhou, et al., Photonics Research, Vol. 5, p 108, (2017)Comparisons with MZI / MRR272x2 SwitchDevice footprintTO tuning efficiency Switching powerMZI 110000 m2-30mWMMR 2400 m20.25 nm/mW3.3mWOur work4500 m21.23 nm/mW

23、0.16mW*Effective TO tuningUltra-low switching powerRef. 1 K. Suzuki, OPTICS EXPRESS 23(7), 2015.Ref. 2 Q. Li, PHOTONICS TECHNOLOGY LETTERS, 27(18), 2015.Our 2x2 TO nanobeam switch achieves:* switching power with a 3dB-bandwidth wavelength shift. 2828OutlineAbout AEMD centerHigh-efficiency (19 nm/mW)

24、 nanobeam thermo-optic filterLow-power (0.16 mW) nanobeam 2x2 thermo-optic switchSubwavelength-grating bandpass filter with high sidelope suppression (27 dB)High extinction ratio (30 dB) polarization beam splitterUltra-compact polarization beam splitter and rotatorSummarySilicon sub-wavelength grati

25、ng (SWG)29Ref: P. J. Bock, et al., NRCC, Opt. Express 18(19): 20251 (2010)Challenge：Small feature size (30nm)Advantages：Flexible controlling of effective refractive indexLow optical nonlinearityHybrid integration：index matchPitch：Sub-wavelength (27 dB)High extinction ratio (30 dB) polarization beam

26、splitterUltra-compact polarization beam splitter and rotatorSummaryBirefringence of silicon nanowire 35D. Dai et al., Laser Photonics Review 7(3), 2013Silicon photonic-integrated circuits:Considerable birefringence values of silicon nanowirePolarization-dependent dispersion or lossTE0 modeTM0 modeTy

27、pical single-mode waveguide: 500 nm 220 nmPolarization-diversity scheme36T. Barwicz et al., Nature Photonics 1, 2007Key devices:Polarization beam splitter (PBS)Polarization rotator (PR)Goals of the PBS:High polarization extinction ratio (PER)Low insertion lossPolarization-diversity schemeWide operat

28、ion bandwidthLarge tolerance .Function of the PBSCombining or splitting two orthogonal polarization modesProposed silicon PBS37Based on grating-assisted contradirectional coupler (GACC) TE mode: couplingTM mode: no couplingYong Zhang, et al., Opt. Express, Vol. 24, p 6586, (2016)Yong Zhang, et al.,

29、in Proc. OFC, 2016, paper Tu3E.2PERs for different N38N: corrugation period number PER: polarization extinction ratio PERs for TE inputPERs for TM inputAs coupling length increases, PER increases for TE input.Trade-off between the PER and device length.Fabrication of the PBS 39ProcessSEM images of t

30、he fabricated PBSExperimental results of high PERs40PERs 30 dB for both polarizations between 1517 1538 nm.Insertion losses 15 dB for both polarizations w/ the coupling length varied from 30.96 mm to 13.76 mm at the central wavelength.Tolerant to waveguide width variations 42PER 20 dB for both polar

31、izations w/ width variations from +10 nm to 10 nm at the central wavelength.Comparison of various silicon PBSs43StructuresPER (dB)Insertion loss (dB)Operation bandwidth (nm)ToleranceDouble-etched directional coupler 120 0.5 30 -Mode-evolution-based PBS 2 10 3.5150 -Nonlinear-search-algorithm-based P

32、BS 310-32 20 nm for silicon thicknessMMI-based PSR 412 2.5100 50 nm for widthBent directional coupler 510 6 dB20 nm for widthBridged directional coupler 6 23 2.18010 nm for width;6.5 8.5 mm for lengthDirectional coupler 7150.550 -GACC-based PBS (our device)3027 dB)High extinction ratio (30 dB) polar

33、ization beam splitterUltra-compact polarization beam splitter and rotatorSummaryPolarization splitter and rotator45Ref: T. Barwicz et al., Nature Photonics 1, 2007Key devices:Polarization beam splitter (PBS)Polarization rotator (PR)OrPolarization splitter and rotator (PSR)Goals of the PSR:Low insert

34、ion lossCompact footprintPolarization-diversity schemeWide operation bandwidthLow crosstalk .Function of the PSREfficient polarization splitting and rotating are simultaneously achievedOur proposed silicon PSR46Based on a bent directional coupler Cross-polarization coupling TM-polarized inputSymmetries are broken by:Vertical: air as upper claddingHorizontal: different widthsYong Zhang, et al., in Proc. ECOC, 2016, Th1B.4.Yong Zhang, et al., APL Photonics, Vol. 1, p 091304, (2016).Width design of the PSR 47TM WG1TE WG2TE WG1TE/TM