, 2012 10 SCOPE, 2012 10
2 CDMA OFDMA OFDM SCOPE, 2012 10 OFDM 0-20 Relative Optical Power [db] -40-60 10 Gbps NRZ BPSK-SSB 36dB -80-20 -10 0 10 20 Relative Frequency [GHz]
SSB SSB OFDM SSB SSB OFDM OFDM OFDM Ch1 BER 10 0 10-1 50km + 50km 10-2 10-3 10-4 10-5 10-6 10-7 10-8 44 46 48 50 52 Electrical field amplitude [dbμv]
4 SSB 100km SSB OHT EHT OHT SSB OHT SSB SCOPE, 2012 10
(SSB) 5 (1) SSB (2) LD LN-Mod LD LN-Mod ω SG c ω ω c ω SG (3) SSB (4) SSB LD LN-Mod-SSB LD LN-Mod π/2 π/2 HT SG HT ω c ω SG ω c ω HT: Hilbert Transformer () SCOPE, 2012 10
SSB 6 f in f in (t) ( t) cos( ω t) = SCOPE, 2012 10 s f out cos(ω c t) π 2 = cos( ω π 2 s c ωs ) t f out (t) 0 ω ω c 0 ω c ( t) = cos( ω t)cos( ω t) + sin( ω t)sin( ω t) c DSB-SC () s 1/2 c SSB-SC ω π/2
SSB 7 CW light d(t) d(t) In-Phase Modulated light Optical waveguide Electrode (phase modulator) Baseband Signal Generator SCOPE, 2012 10 ± π/2 Hilbert Transformer d H (t) d H (t) E/O d(t) d H (t) H(ω) Quadrature-Phase S. Shimotsu et al., PTL, 13, 4, pp.364-366, (2001). Application: Advanced Modulation (FSK, DQPSK, SSB etc. ) H(ω) arg{h(ω)} 1 π 0 ω π 2 0 ω 2
8 Antenna 75 -> 50 Impedance Converter BPF 460-600 MHz LD G: 40dB 90 o Hybrid I Q (Hilbert Trans.) P-Con Bias I : Quad. Q: Null D-Line: optical tunable delay line ATT: optical variable attenuator P-Con: polarization controller OSA: optical spectrum analyzer Scope: oscilloscope with optical interface SMF Impedance Converter 75 <- 50 Evaluation Equipment PD & TIA λ C :1552.5nm 10 db Coupler Monitor LN-Mod DC Δλ: 0.9nm ATT Tunable BPF Optical Attenuator Isolator Isolator 50 km EDFA G: 24dB NF: 5.0dB SMF 50 km SCOPE, 2012 10
SSB 9 f S : 5 GHz LD 90 o Hybrid I Q (Hilbert Trans.) P-Con 600mVpp Bias I : Quad. Q: Null λ C :1552.5nm LN-Mod DC Isolator Scope OSA SCOPE, 2012 10 SSR: 12.902dB
10 NHK-E NHK-G YTS TUY YBC SAY Ch. No. TV ch. Freq. MHz Ch. No. TV ch. Freq. MHz 24 NHK-E 536-542 34 YTS 596-602 28 NHK-G 554-560 37 TUY 614-620 32 YBC 584-590 40 SAY 632-638 SCOPE, 2012 10
11 BER 10 0 10-1 B to B 24ch 10-2 10-3 10-4 10-5 10-6 10-7 10-8 28ch 32ch 34ch 37ch 40ch 44 46 48 50 52 Electrical field amplitude [dbμv] BER 10-1 10-2 10-3 10-4 10-5 10-6 10-7 10-8 BER 2 10-4 10 0 50km + 50km 44 46 48 50 52 Electrical field amplitude [dbμv] Penalty [db] 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 24ch 28ch 32ch 34ch 37ch 40ch TV channel RF ch SCOPE, 2012 10
OFDMEDFA 12 WDM EDF (1480 nm) [nm] α [db/m] g [db/m] P SAT [mw] 1480.0 0.961 0.286 0.640 1552.5 1.380 2.078 0.220 9.9ms 100mW EDF : 14m 14.3dB 14dBm NF 6dB Gain [db] 16 14 12 10 BPF EDFA (-4.8dBm, 12.8dB) 8 6 4-40 -30-20 -10 0 10 Input power [dbm] 10 8 6 NF [db] SCOPE, 2012 10
EDFA 13 EDFA gain [db] 13.2 13 12.8 12.6 EDFA [db] 0.5 0.4 0.3 0.2 0.1 SCOPE, 2012 10 Subcarrier: 32 0 0.05 0.1 0.5 1 5 10 [Mbps] 0 500 1000 1500 Time [μs] 13.2 B: 80kbps B: 8 Mbps EDFA gain [db] 13 12.8 12.6 0 5 10 15 Time [μs]
3 14 3 FIR h hil (n) Mach-Zehnder (MZI) Input fiber M: mirror HM: half mirror CM: corner mirror M2 SCOPE, 2012 10 3 rd order R 1 HM1 n CM CM M1 R2 HM2 Z 1 + Z 1 h(0) h(1) h(2) Output fiber + c > B ΔL λ C ΔL = ( 2i 1) 2 h(1)=0 ΔL: path difference B: bit rate i: integer
SSB 15 LD LN-Mod EDFA BPF ATT D-Line I 1:1 1:1 λ C :1552.5nm V DRV : V π Bias: Null f S : 10 GHz SSB O-HT (MZI) 8.11 db FSR: 43 GHz OSA P-Con 10 db Coupler Q Isolator Scope Upper sideband Lower sideband nearly DC. SCOPE, 2012 10 t
OHT 3 7 (a) 3-5 -4 h(n) 2, n = odd h( n) = nπ 0, n = even -3-2 -1 τ n (b) 7 MZI_1 h(n) τ MZI_2-5 -4-3 -2-1 n 0 1 2 3 4 5 0 1 2 3 4 5 Input 1:1 2τ π Output Input 1 α : α DL_1 2τ 1:1 1:1 2τ 6τ π π MZI_1 MZI_2 Output SCOPE, 2012 10
SSB 7 OHT LD LN-Mod EDFA BPF λ C :1552.5nm [db] V DRV : V π Bias: Null f S : 10 GHz SCOPE, 2012 10 1:1 SSB 10.97 db LSB USB ATT USB: LSB: D-Line P-Con LD: Laser diode LN-Mod: LiNbO 3 Intensity modulator EDFA: Er 3+ doped fiber amplifier BPF: Optical bandpass filter D-Line: optical tunable delay line 1:1 OSA I Q Isolator Scope ATT: optical variable attenuator P-Con: polarization controller OSA: optical spectrum analyzer Scope: oscilloscope with optical interface
3 7 (a) 3 (b) 7 22.5 GHz 35 GHz 3 or 7 OSA SCOPE, 2012 10
10 Gbps PN: 7-stage(NRZ) SCOPE, 2012 10 - - d(t) PPG d(t) Hilbert Transformer H(ω) LD λ s : 1550 nm d H (t) H I (ω) arg{h I (ω)} 1 ω 0 0 H I ( ω) Ideal H.T. = j sgn 0 π 2 π 2 ( ω) ( ω 0) ( ω = 0) d H (t) ω V B (t) V B (t) V H (t) V H (t) H H ω c LN - SSB modulator π/2 Mod. depth: 0.05 Bias point: null to transmission fiber PPG: Pulse Pattern Generator LD: Laser Diode LN: Lithium Niobate H H (ω) arg{h H (ω)} 1 1 2 π 2 ω 0 ω c 0 π 2 j sgn ω ω > 2ωc ω = j sgn( ω) sin 2π ( ω 8ω c ) ω 2ωc ω c = 2πf c, f c : Cut-off frequency ( ) High-pass H.T. 19 ω ( ) ( ) { } ( )
HT SSB 20 理想 HT: 無 f c = 0.5 GHz HT f c = 3 GHz f c = 5 GHz [db] 4 3 2 1 I-HT Optical SSB-SC f c [GHz] HP-HT Optical SSB (0.5) HP-HT Optical SSB (1.5) HP-HT Optical SSB (3.0) HP-HT Optical SSB (5.0) 0-15 -10-5 0 5 10 15 [dbm] SCOPE, 2012 10 (x: 0.05, P t,ave : 8 dbm) SPM (EOD = 1dB) 15.3 db SPM