Combination of Transverse Mode Selection and Active Longitudinal Mode-Locking of Broad Area Semiconductor Lasers

Figure 8

Measured pulse width (FWHM)—using a different BAL sample as compared to the case of Figure 4—for different distances 𝑑 of the spatial frequency filter slit to the optical axis. The pulse duration increases nearly linearly by about 3.2% with each increment of the transverse mode number 𝑚.