Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

Outline

1. Silicon Photonics 2. Waveguide Simulations 3. MODE Solutions 4. Example

• Silicon Photonic Design(2012 Lukas Chrostowski)

• yunsu.sys@gmail.com

mailto:yunsu.sys@gmail.com

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

Silicon Photonics • Silicon Photonics

Photonic system which use silicon as optical medium Use SOI wafer Can be made using conventional semiconductor fabrication

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

Silicon Photonics

• Structure of photonic SOI chip

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

Silicon Photonics

• Laser

• Grating Coupler

Couple light into and out of photonic chip.

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

Silicon Photonics

• Modulator Modulate a beam of light Electrical signal Optical signal

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

Silicon Photonics

• Waveguide Physical structure that guides EM waves Core: Silicon Cladding: Silicon oxide or Air

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

Silicon Photonics

• Photodetector Sensor of light Optical signal Electrical signal

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

Silicon Photonic

Need simulation!

Chip fabrications a lot of money

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

Waveguide Simulation

• Finite Difference Time Domain (FDTD) Numerical method of solving Maxwell equation 1) 3D FDTD

Accurate Slow

2) 2D FDTD 3) 2.5D FDTD

2D FDTD with effective index method Fast Approximation

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

Waveguide Simulation

• Eigenmode solver Solution method in a cross-section of waveguide geometry Solve Maxwell equations for cross-sectional mash

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions

• Lumerical MODE Solutions Eigenmode solver Propagation solver (2.5 FDTD)

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions • Download trial version https://www.lumerical.com/

Need official E-mail(Ex: @yonsei.ac.kr) for download

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions

• Make account at Lumerical homepage • Download license • Don’t run program at home

• 4/3 Class at A125(computer lab) • Bring USB with downloaded license

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions

• Drawing structure – Example) Make strip waveguide – Height: 220 nm – Width: 500 nm – Length: 30 μm – Core material: Si – Cladding material: SiO2

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions

• Parameter can be predetermined here(material, number)

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions • Code for make cladding

• Geometry set

1. x, x span 2. z min, z max

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions

• Result of cladding

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions

• Include core

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions

• Result

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

Example

• Make rib waveguide • Core: Si • Cladding: SiO2

900nm

500nm

220nm 130nm

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions

• Run simulation of made structure • Calculate effective index of mode 0

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions

• Run simulation

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

MODE Solutions

Advanced Topics in Photonic Devices (14/1) W.-Y. Choi

Example

1. Find the group and phase velocity of light for the fundamental TE and TM modes in the following waveguides -slab waveguide, 220 nm thick, 500nm with at 1550 nm

2. What is the single-mode condition for the ridge waveguide TE mode? What is the maximum width for the waveguide before it supports more than one mode? What is the minimum width for the silicon before it does not support a mode?

OutlineSilicon PhotonicsSilicon PhotonicsSilicon PhotonicsSilicon PhotonicsSilicon PhotonicsSilicon PhotonicsSilicon PhotonicWaveguide SimulationWaveguide SimulationMODE SolutionsMODE SolutionsMODE SolutionsMODE SolutionsMODE SolutionsMODE SolutionsMODE SolutionsMODE SolutionsMODE SolutionsMODE SolutionsExampleMODE SolutionsMODE SolutionsMODE SolutionsMODE SolutionsExample