Intensity pattern types in broadband Fourier domain mode-locked (FDML) lasers operating beyond the ultra-stable regime

We report on the formation of various intensity pattern types in detuned Fourier domain mode-locked (FDML) lasers and identify corresponding operating conditions. Such patterns are a result complex laser dynamics serve as an ideal tool for study underlying physical processes well model verification. By numerical simulation we deduce that is related to spectral position instantaneous lineshape with respect transmission window swept bandpass filter. The properties determined by long-term accumulation phase-offsets, resulting rapid high-amplitude fluctuations time due narrow intra-cavity filter fast response semiconductor optical amplifier gain medium. Furthermore, present distribution duration dips trace running regime which dominantly form, give insight into their evolution over large number roundtrips.