Influence of the linewidth enhancement factor on the signal pattern of Fourier domain mode-locked lasers

Abstract Fourier domain mode-locked (FDML) lasers are frequency-swept that operate in the near-infrared region and allow for attainment of a large sweep-bandwidth, high sweep-rate, narrow instantaneous linewidth, all which usually quite desirable characteristics laser. They used various sensing imaging applications but most commonly noted their practical use optical coherence tomography (OCT). An FDML laser consists three fundamental components, semiconductor amplifier (SOA), fiber, wavelength-swept bandpass filter. Due to complicated nonlinear dynamics stems from coaction these often output signal an is corrupted by frequent power-dips varying depth duration. The recurrence dips pattern lowers quality detection. This study examines role linewidth enhancement factor (LWEF) SOA reducing both strength number throughout operation. results obtained using numerical computations agreement with experimental data. aims show SOAs low LWEFs, can be reduced better detection quality.