60-fs pulses from a diode-pumped Nd:glass laser

Abstract

We demonstrate 60-fs pulses with an average output power of 84 mW from a diode-pumped Nd:glass laser mode locked by a low-finesse antiresonant Fabry-Perot saturable absorber (A-FPSA). The mode-locked spectrum spreads over most of the available Nd:glass fluorescence bandwidth. At increased pulse energy fluence or decreased negative group-velocity dispersion, multiple pulsing was observed. We experimentally characterize this behavior, which can be explained by the saturation behavior of the A-FPSA and the limited available gain bandwidth. These considerations are significant for the design of saturable absorbers to achieve stable passive mode locking.

Multipulse operation of a Ti:sapphire laser mode locked by an ion-implanted semiconductor saturable-absorber mirror

“…Similar transitions were reported previously in other SESAM and semiconductor Bragg reflector mode-locked soliton lasers. 4,10 However, from the pulse energies, and assuming firstorder solitons for both the single-and the double-pulse cases, one should expect a larger jump in pulse width than that indicated in Fig. 2.…”

“…More recently, the breakup of single pulses into multiple pulses was seen in a Kerr lens mode-locked Ti:sapphire laser 3 as well as in other solidstate lasers mode locked by semiconductor saturableabsorber mirrors (SESAM's). 4 In these cases the spacing between pulses was generally much larger than the single-pulse width, was irregular, and was subject to spontaneous changes.…”

Multipulse operation and limits of the Kerr-lens mode-locking stability

“…It should be noted that the transition to multipulse operation is not the sole scenario of the stability loss in the continuous-wave (CW) mode-locked solid-state lasers: the automodulational instability can produce regular as well as nonregular oscillations of the single pulse or the so-called picosecond collapse with the abrupt transition from the femtosecond to the picosecond generation [17], [18]. The stable multipulse operation in the negative GDD region was experimentally observed in Ti:sapphire [1], [19]- [21], Cr:LiSGaF [22] and Yb:KYW [23] Kerr-lens mode-locked lasers as well as in Nd:glass [24], Ti:sapphire [4], and Cr :YAG [25] lasers mode locked by a semiconductor saturable absorber mirror. In [26], the tendency toward multipulse generation was reported for the positive-GDD regime in the Cr :ZnSe laser with passive mode locking initiated by acousto-optical modulation.…”

Temporal Change of Thermal Lens Effects on Highly Pumped Ytterbium Glass by Wavefront Measurement

“…On the other hand, another possibility has been pointed out that the laser system could become more compact by laser diode pumping. 4,5) Alternative gain materials such as Yb:glass having lower quantum defect and available for laser diode pumping could be one of the promising candidate. 6,7) After the first Yb:glass regenerative amplifier by a flashlamp pumped Ti:sapphire, 8) the direct-laser-diode pumped regenerative amplifier was succeeded.…”