Fourier Domain Mode Locking (FDML) is a technique used in fiber optics and laser technology to achieve high-speed, high-resolution measurements. It is primarily applied in optical coherence tomography (OCT) and other applications where rapid scanning and imaging are critical. ### Key Concepts of FDML: 1. **Mode Locking**: Traditional mode locking techniques in lasers involve the interference and constructive or destructive combination of different longitudinal modes of the laser to produce very short pulses of light.