Fe₃O₄ nanoparticles as a saturable absorber for giant chirped pulse generation

• Ji-Shu Liu,
• Xiao-Hui Li,
• Abdul Qyyum,
• Yi-Xuan Guo,
• Tong Chai,
• Hua Xu and
• Jie Jiang

Beilstein J. Nanotechnol. 2019, 10, 1065–1072, doi:10.3762/bjnano.10.107

• pulse duration of 55 ns, which is the shortest pulse duration published to date. It is well-established that the RPR will increase with the increase in pump power when the device is in the Q-switching state [40][41][43][44][45][46]. In our results, we demonstrate that as the pump power is increased, the

Oriented zinc oxide nanorods: A novel saturable absorber for lasers in the near-infrared

• Pavel Loiko,
• Tanujjal Bora,
• Josep Maria Serres,
• Haohai Yu,
• Magdalena Aguiló,
• Francesc Díaz,
• Uwe Griebner,
• Valentin Petrov,
• Xavier Mateos and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2018, 9, 2730–2740, doi:10.3762/bjnano.9.255

• nanorods; Q-switching; saturable absorption; solid-state lasers; zinc oxide; Introduction Zinc oxide (ZnO) is a well-known II–IV group wide-bandgap semiconductor (Eg = 3.37 eV), possessing a hexagonal wurtzite-type (sp. gr. P63mc) structure with unit cell parameters a = 3.25 Å, c = 5.20 Å. In recent years

• with picosecond pulses resulting in Isat = 16 kW/cm2, which is close to our observations. Passive Q-switching by ZnO nanorods The laser experiments were performed with the NRs grown for 5 h, because they exhibited minimum insertion loss. Stable Q-switching was also observed for the NRs grown for 10 h

• scaling of the laser in the PQS regime was limited by the Q-switching instabilities arising for Pabs > 3.2 W due to the heating of the SA by the residual (non-absorbed) pump [22]. The pulse duration Δτ, determined as full width at half maximum (FWHM) and the pulse repetition frequency (PRF) for the PQS