University:
California State University, East Bay
Course:
CS 3590 | Data Communications and Networking
Academic year:

2023
Views:

410

Pages:

1
Author:

Jithin J I

QUASI-PHASE MATCHING USING TOTAL INTERNAL REFLECTION AND OPTICAL ROTATION Introduction  Quasi-phase matching (QPM) techniques used to overcome phase mismatch in nonlinear optics  Periodic poling has fabrication errors that cause decreased harmonic generation  Optical rotation QPM (ORQPM) gives higher efficiency than conventional QPM Operational Principle  ORQPM based on total internal reflection (TIR) in electro-optic chiral materials  External electric field controls polarization rotation  Combines ORQPM and fractional QPM for efficient second harmonic generation Phase Matching Conditions  Ideal ORQPM: rotation period = 2 x coherence length  Near optimal achieved with rotation period = 8 x coherence length  101 bounces needed for 2π polarization rotation of second harmonic Modeling and Simulation  Numeric-analytical model accounts for losses, surface roughness, phase shifts  MgO:LN crystal slab with Y2O3 thin film coating analyzed  Beam propagation and second harmonic generation simulated Key Results  Highest efficiency with incident angle around 40 degrees  Thin film thickness of 2 μm gives best performance  External electric field controls polarization rotation period Conclusion  Near optimal ORQPM enables efficient nonlinear frequency conversion  Model provides guidelines for designing integrated ORQPM devices