All-Optical Wavelength Conversion for NRZ-OOK Signal based on - PowerPoint PPT Presentation

All-Optical Wavelength Conversion for NRZ-OOK Signal based on Four-Wave Mixing in a Silicon Waveguide Simon Lindståhl & Elias Riedel Gårding Supervisors: Prof. Gao Shiming and Yang Xiong, Laser group Centre for Optical and Electromagnetic Research, Zhejiang University June 28 – July 15, 2016 Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 1 / 13

Introduction Fibre optical communications Advantages High bandwidth Low loss but All-optical systems not fully developed Cannot transfer high power Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 2 / 13

Introduction OOK signals & wavelength conversion On-off keying (OOK) No light is 0 , light is 1 . Simplest modulation format NRZ-OOK vs RZ-OOK Wavelength conversion To convert a beam to another wavelength preserving the signal. Allows wavelength division multiplexing Some components need specific input wavelengths Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 3 / 13

Introduction Four-wave mixing (FWM) Nonlinear effect: depends on � P = ε 0 χ e � E + � P NL Parametric (instantaneous) process Two photons ( ω 1 , ω 2 ) in, two photons ( ω 3 , ω 4 ) out Energy and momentum conservation ω 1 + ω 2 = ω 3 + ω 4 frequency matching � � � � k � = n ( ω ) ω � k 1 + � k 2 = � k 3 + � c k 4 phase matching When ω 1 = ω 2 : Degenerate FWM ( ω i = 2 ω p − ω s ) Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 4 / 13

Introduction Components Passive ◮ Attenuators ◮ Isolators (ISO) ◮ Optical couplers ◮ Polarization controllers (PC) ◮ Wavelength division multiplexers (WDM) ◮ Modulators ⋆ Mach-Zehnder modulator (MZM) (amplitude modulator) Active ◮ Tunable lasers (TL) ◮ Amplifiers ⋆ Erbium doped fibre amplifier (EDFA) Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 5 / 13

Preparatory experiments Generally educational 1 Fibre fusion splicing 2 Properties of passive components 3 Construction of a fibre laser 4 Properties of an optical amplifier Directly preparatory 1 Continuous wave wavelength conversion (in fibre) 2 Modulation of an OOK signal Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 6 / 13

Main experiment Setup Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 7 / 13

Main experiment Setup Clock out Signal Generator Microwave Data out Ampli fi er Bias Data in PC1 PC2 HP-ISO ISO TL1 HP-EDFA1 MZM Pass (1550.80 nm) PC3 HP-ISO ISO Pass TL2 WDM1 WDM2 (1553.38 nm) Re fl . COM HP-EDFA2 COM Re fl . Discard SOI PC4 PBS Output Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 8 / 13

Main experiment Measurements (optical spectrum analyser) Clock out Signal Microwave Generator Data out Ampli fi er Bias Data in (a) Continuous (b) OOK signal PC1 PC2 ISO HP-ISO TL1 HP-EDFA1 MZM Pass (1550.80 nm) PC3 ISO HP-ISO TL2 WDM1 Pass WDM2 COM (1553.38 nm) Re fl . HP-EDFA2 Re fl . COM Discard SOI PC4 PBS Output (c) Filtered OOK signal Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 9 / 13

Main experiment Measurements (power levels) (dBm) CW OOK Clock out Signal Signal after PBS 17 . 84 15 . 7 Generator Microwave Data out Ampli fi er Bias Data in Pump after PBS 25 . 1 26 . 16 PC1 PC2 HP-ISO ISO TL1 Combined after SOI 23 . 3 23 . 71 HP-EDFA1 MZM Pass (1550.80 nm) PC3 HP-ISO ISO Pass TL2 WDM1 WDM2 (1553.38 nm) Re fl . COM HP-EDFA2 COM Re fl . Converted signal: − 20 dBm = 10 µW Discard SOI PC4 PBS Output � � P P dBm = 10 log 10 1 mW 0 dBm 30 dBm 1 mW 1 W Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 10 / 13

Main experiment Measurements (oscilloscope) Clock out Signal Microwave Generator Data out (a) Before EDFA (b) After EDFA Ampli fi er Bias Data in PC1 PC2 HP-ISO ISO TL1 HP-EDFA1 MZM Pass (1550.80 nm) PC3 ISO HP-ISO Pass TL2 WDM1 WDM2 COM (1553.38 nm) Re fl . HP-EDFA2 Re fl . COM Discard SOI PC4 PBS Output (c) After WDM2 None available for the converted signal! Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 11 / 13

Thank you! Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 12 / 13

Image sources By http://www.ictas.vt.edu - http://www.ictas.vt.edu , CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=45474605 http://www.geeky-gadgets.com/wp-content/uploads/2011/09/ wicked-lasers-krypton.jpg http://pigselectronics.com/images/ INFINITER-100-Red-Laser-Pointer-Silver-Perfect-Gift-Ideas-for- jpg Simon & Elias (Laser group) Wavelength conversion by FWM June 28 – July 15, 2016 13 / 13