Using Q-Finder to Automate Cavity Mode and Q Calculations
应用文章
This application example illustrates the use of Q-Finder, an automated utility for computing cavity modes and Q factors. A basic example is shown using a hexagonal array of air holes in a silica slab with a missing center hole to form a defect.
The field is monitored in the defect region, and the Fast Harmonic Analysis (FHA) method is used to extract accurate resonant frequencies and Q values from relatively short FullWAVE simulations. For this structure, Q-Finder calculates a Q of 3363 at a resonant frequency of 0.63497 μm⁻¹ and a mode volume of 0.12.
A scanning example is also included to show how Q-Finder works with MOST, Keysight’s Multi-Variable Optimization and Scanning Tool. The same structure is used, but a central hole is added to the defect region, and its size is scanned from 0 to 0.2 μm. After the scan, the Q values are examined using the DataBROWSER. The results show that Q reaches a minimum when the defect is effectively removed, resulting in a very lossy system.