Femtosecond pulses with high energies from a coupled-cavity saturable-absorber mode-locked KCl F(A)(Tl) color-center laser.
By using a bulk InGaAsP saturable absorber, we passively mode lock a KCl F(A)(Tl) color-center laser in a resonator configuration where the gain material is placed in a main cavity and the saturable absorber is placed in a weakly coupled external cavity. We obtain self-starting and self-stabilized resonant passive mode-locked laser operation, either with pulses as short as ~320 fs or average output power as high as ~380 mW. The pulse width-bandwidth product is ~0.47, with pulse energies of as much as 2.5 nJ. By temperature tuning the saturable absorber band edge, we realize laser operation with similar performance over the wavelength range of 1.50-1.55 microm. When compared with mode-locked KCl F(A)(Tl) laser operation, where both the gain material and the saturable absorber are placed in a common single cavity, the resonant passive mode-locking technique yields pulses with only moderately increased widths (by ~50 fs) but significantly higher energies (by a factor of ~4).
Möllmann
K
K
Gellermann
W
W
Soccolich
C E
CE
Islam
M N
MN