Generation Of Sub-100 Fs Pulses Research Articles

High power sub 100-fs Kerr-lens mode-locked Yb:YSO laser pumped by single-mode fiber laser.

We report on a Kerr-lens mode-locked Yb:YSO lasers for the first time. Pumped by a single-mode fiber laser with high brightness and linear polarization, the Yb:YSO laser can deliver as high as 2 W average power with as short as 95 fs pulse duration at the repetition rate of 137.2 MHz, resulting in the single pulse energy of 14.8 nJ and the peak power of 155.7 kW. This work proves the potential on generation of sub-100 fs pulses with multi-watt level average power with the Yb doped oxyorthosilicates crystals.

Kerr-lens mode-locked Yb3+-doped Lu3Al5O12 ceramic laser.

Yb:LuAG is a promising gain medium for high-power lasers due to its high thermal conductivity and large emission cross section. Although narrowband gain media such as Yb:LuAG are not considered to be suitable for the generation of sub-100 fs pulses, we have achieved generation of 91 fs pulses with Yb:LuAG ceramic by the Kerr-lens mode-locking (KLM) technique. The obtained average power, pulse energy, and peak power were 1.64 W, 20.0 nJ, and 220 kW, respectively. These are, to the best of our knowledge, the first demonstration of KLM and the new records based on both Yb:LuAG ceramic and single crystal.

Generation of sub-100 fs pulses from mode-locked Nd,Y:SrF2 laser with enhancing SPM

A mode-locked laser using Nd,Y:SrF2 crystal as the gain medium is presented in this letter. By special design of the cavity for enhancing the self-phase modulation effect, femtosecond mode-locking with 97 fs pulse duration and 13.2 nm spectral width centered at 1061 nm is obtained at a repetition rate of 96 MHz. The average output power is 102 mW under 925 mW pump power, corresponding to the optical-to-optical efficiency of 11%. To the best of our knowledge, these are the first sub-100 fs pulses generated from a mode-locked Nd doped crystal laser.

Sub-100 fs mode-locked erbium-doped fiber laser using a 45°-tilted fiber grating

We demonstrate generation of sub-100 fs pulses at 1.5 µm in a mode-locked erbium-doped fiber laser using a 45°-tilted fiber grating element. The laser features a genuine all-fiber configuration. Based on the unique polarization properties of the 45°-tilted fiber grating, we managed to produce sub-100 fs laser pulses through proper dispersion management. To the best of our knowledge, this is the shortest pulse generated from mode-locked lasers with fiber gratings. The output pulse has an average power of 8 mW, with a repetition rate of 47.8 MHz and pulse energy of 1.68 nJ. The performance of laser also matches well the theoretical simulations.

Sub-100 fs pulse generation in a diode pumped Yb:Sc2SiO5 laser

We report on the sub-100fs pulse generation in a diode pumped Yb3+:Sc2SiO5 (Yb:SSO) laser. Pumped by a 976nm single emitter diode and mode-locked with a SESAM, the laser generated stable mode locked pulses with 71fs duration, 89MHz repetition rate, and an average power of 38mW at 1044.6nm under the incident pump power of 6.5W. To the best of our knowledge, this is the shortest pulse ever produced from an Yb3+ doped orthosilicate crystal laser.

Analysis of Possible Group-Velocity-Matched Broadband Second-Harmonic Generation in Various Periodically Poled Nonlinear Crystals

For the efficient second-harmonic generation of ultrashort pulses in wide spectral ranges, we theoretically studied all possible group velocity matched broadband frequency conversion processes in different periodically poled materials, using quasi-phase matching. Important parameters such as the poling period, type of interaction, spectral bandwidth and conversion efficiency are estimated in detail. The results show that some materials can be efficiently applied to the generation of sub-100 fs pulses near the wavelengths of a widely used Ti:sapphire laser.