Optical linewidth of a passively mode-locked semiconductor laser.
We measured the optical linewidths of a passively mode-locked quantum dot laser and show that, in agreement with theoretical predictions, the modal linewidth exhibits a parabolic dependence with the mode optical frequency. The minimum linewidth follows a Schawlow-Townes behavior with a rebroadening at high power. In addition, the slope of the parabola is proportional to the RF linewidth of the laser and can therefore provide a direct measurement of the timing jitter. Such a measurement could be easily applied to mode-locked semiconductor lasers with a fast repetition rate where the RF linewidth cannot be directly measured.
Habruseva
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T
Tyndall National Institute, Lee Maltings, Cork, Ireland. tatiana.gabruseva@gmail.com
O'Donoghue
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S
Rebrova
N
N
Kéfélian
F
F
Hegarty
S P
SP
Huyet
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G