/ 2008/04/04 Ferran Salleras 1
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40Gb/s 40Gb/s PC QD PC: QD: e.g. PCQD PC/QD 3
CP-ON SP T CP-OFF PC/QD-SMZ T ~ps, 40Gb/s ~100fJ T CP-ON CP-OFF 500µm500µm Photonic Crystal SMZ K. Tajima, JJAP, 1993. Control Pulse Signal Pulse Control Pulse Output Signal QD-Based Large NL (χ 3 ) Media H. Nakamura et al., Opt. Exp. 12, 6606, 2004. PC/QD-FF Flip-Flop φ K. Asakawa et al., New J. Phys. 8, 208, 2006. 4
PC/QD PC/QD FUTURE PC/QD-SMZ -FF 10fJ/pulse 40-Gb/s 5
(a) 250nm (b) Air-bridge (2µm) 300nm (d) 250nm Air-bridge (2µm) QDlayers GaAs core-layer (250nm) 2 PC GaAs QD InAs (a) (b) : 110nm (c) 410 10 cm -2 (d) + SEM 23mW (c) TARA 6
500µm (Frequency, ω 2 : 81.2MHz) (Probe) Lensed-fiber MO BS MO Sample Lock-in amp. Delay stage BPF Photoreceiver AOM (Frequency, ω 1 : 78.7MHz) MO Lens BS Q H AOM BS H BPF Q Delay stage OPO: AOM: PBS: SMF: MO BPF: MO: H: / Q: / (Reference) SMF MO PBS (Pump) H OPO (Repetition rate: 80MHz, Pulsewidth: 150fs) 7
CB e-es e-gs h-gs h-es VB ref ref QD e h GS ES CB VB E E I pro beat = = P P ( E I beat pro ref cos{( ω + ω1) t} ( t, P + E P pump pro ref ) ) cos{( ω + ω 2 ) t + φ( t, Ppump )} 2 P pro ( t, P pump ) cos {( ω ω ) t + φ( t, P )} Ppro(t, Ppump) φ(t, Ppump) AOM ω 1 ω 2 78.7MHz 81.2MHz 1 2 pump 8
Peak power (nw) 5 4 3 2 1 with PC/QD w/o PC/QD Noise level at with PC/QD 440fs 360fs 0 0 0 0.5 1 1.5 2 2.5 3 3.5 200 100 Probe/Reference delay time (ps) SOA 440fs 915dB Peak power (nw) Normalized amplitude (a.u.) 0.5 1 0 1.3ps Amplitude Phase 0 0 5 10 15 20 Delay time (ps) 1.3µm-SOA (InPhenix) @ 150mA τ phase = ~300ps : 1.25pJ/pulse @ 1310nm : 20fJ/pulse @ 1330nm 200 100 9 Phase (deg.)
Amplitude (a.u.) 0.1 0.08 0.06 0.04 0.02 0 Pump energy 150fJ/pulse 100fJ/pulse 0 50 100 150 200 250 Pump/Probe delay time (ps) 18ps + 30ps + 80ps 13ps + 23ps + 115ps Phase shift (deg.) +80 +60 +40 +20 0-20 Pump energy 150fJ/pulse 100fJ/pulse 0 50 100 150 200 250 Pump/Probe delay time (ps) 60ps + 90ps 40ps + 100ps 1300nm 150fJ/pulse 100fJ/pulse 1310nm 7.5fJ/pulse 10
PC/QD 440ps 10dB -SOA 11
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PC/QD-FF 1 2 S B R A3 SW-2 SW-1 Clock or CW A2 A1 Q T Feed-back 500µm S B R A3 Y- Junction Directional Coupler () 500µm QD A2 A1 Q 13
PC/QD MEB g ro w th GaAs core AlGaAs c lad GaAs sub. EB & RIBE dry etching Wet etching N. Ikeda et al., IPRM. 19, ThB1-4, 2007. EB lithography Cl 2 -RIBE HF wet etching N. Ikeda et al., SST. 22, 149, 2007. 14
Intensity [arb.u.] (a.u.) 40000 30000 20000 10000 Photon energy (ev) Photon energy [ev] 1.1 1.05 1 0.95 0.9 Center: 1290nm FWHM: 32meV ES GS Center 1290nm FWHM 32meV 0 1100 1200 1300 1400 Wavelength [nm](nm) QDPL PC/QD GS: ES: Transmission (dbm) PC transmission window 1280 1320 1360 QD : 1290nm PL : 1290nm PC : 80nm 12801360nm FWHM: 32meV -10-20 -30-40 -50-60 QD absorption peak Wavelength (nm) 15
Peak power (db) -20-30 -40-50 -60 Measured Calculated Noise level PC/QD waveguides -90-80 -70-60 -50-40 -30 Probe power (db) 16
Probe intensity (a.u.) 300 200 100 0 Recovery time 119ps 94ps 84ps 0 50 100 150 Pump/Probe delay time (ps) Pump: 150fJ/pulse at 1280nm Probe: 0.1fJ/pulse at 1310nm Pump: 52.5fJ/pulse at 1280nm Probe: 0.25fJ/pulse at 1300nm Pump: 150fJ/pulse at 1280nm Probe: 0.625fJ/pulse at 1310nm 17
Phase (deg.) Real time (s) 0 250 500 90 60 30 0-30 -60-90 0 100 200 Pump/Probe delay time (ps) with cover w/o cover 18