Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

Q: Fachverband Quantenoptik und Photonik

Q 74: Photonics II

Q 74.1: Vortrag

Freitag, 14. März 2025, 14:30–14:45, HS Botanik

CMT-Driven Dual Fitting of 3D FDTD Bragg Grating Reflectance and Transmittance Data — •Yasmin Rahimof, Igor Nechepurenko, M. R. Mahani, and Andreas Wicht — Ferdinand-Braun-Institut (FBH)

Optical Bragg gratings are widely used in research of light-matter interactions and develop photonic devices. Their ability to precisely control wavelength, reflection and transmission characteristics makes them particularly useful in diode laser applications, ensuring reliable performance. The finite-difference time-domain (FDTD) method is widely recognized as one of the most precise techniques for simulating Bragg gratings, as it numerically solves Maxwell's equations. When implemented in 3D, FDTD method can accurately capture the complex interactions between light and intricate geometries or materials, resulting in more accurate simulation outcomes. On the other hand, Coupled Mode Theory (CMT) offers an analytical approach for modeling and predicting the optical response of Bragg gratings. While CMT lacks the dimensional details of 3D FDTD and is therefore generally less accurate, it can still effectively characterize the optical response. In this research, we aim to simultaneously fit the reflection and transmission spectra derived from 3D FDTD simulations with CMT. We investigate how CMT parameters change with different grating lengths. Furthermore, CMT allows us to predict the optical response of longer structures (up to 2 mm) based on data from much shorter structures, approximately 10 times smaller.

Keywords: surface Bragg grating; 3D FDTD simulation; coupled mode theory; surrogate modelling; diode lasers