Authors:

Ethan Chieng Chiao

Date Created:

Not specified

Course Title:

Professor:

Not specified

About Paper:

Bragg gratings are a type of periodic waveguide structure commonly used in optical signal processing applications because they can be easily designed to attain a desired frequency response. A Bragg grating consists of a periodic modulation in the refractive index of the waveguide. This modulation can be observed in the width or thickness of the waveguide. On a silicon photonics platform, Bragg gratings have been used as nearly transparent counter-directional couplers in fully integrated phase calibration systems. This is essential for applications like integrated Fourier transform pulse shaping or optical beam steering for calibration of the relative phase between optical comb lines or spatial emitters, respectively. The goal of this work is to construct a phase interrogator with Bragg gratings suitable for integration with existing Fourier transform pulse shapers. Simulations were first performed using a custom python-based transfer matrix method solver, which generates the frequency response for arbitrary uniform Bragg grating geometries. When known parameters were used, the resulting responses matched expectations. Efforts then transitioned and are currently focused on physical modeling with Ansys Lumerical simulation tools like finite difference time domain (FDTD) and eigenmode expansion (EME) methods. These methods simulate the device geometry following Maxwell's equations. In order to validate the Bragg grating performance, results should align closely between both physical modeling and script simulation. Designs will need to be optimized for weak reflection over broad bandwidth with low optical loss. The performance will be evaluated through circuit-level simulations using the models created in the FDTD and EME simulations. Keywords: Silicon Photonics; Bragg Gratings

Source:

Purdue University / 2024

Topics:

No topics listed

Co-authors:

Ethan Chieng Chiao