Hristo Iliev

High-power picosecond Nd:GdVO4 laser mode locked by SHG in periodically poled stoichiometric lithium tantalate.

Periodically poled stoichiometric lithium-tantalate is used for mode locking of a diode-pumped Nd:GdVO(4) laser by intracavity second-harmonic generation. Stable and self-starting operation is observed achieving average output powers of up to 5 W at a pulse-repetition rate of 107 MHz. The obtained pulse durations range from 6.5 ps at maximum output power down to 3.2 ps at 1.4 W.

Passive mode-locking of a diode-pumped Nd:YVO(4) laser by intracavity SHG in PPKTP.

Experimental results on passive mode-locking of a Nd:YVO(4) laser using intracavity frequency doubling in periodically poled KTP (PPKTP) crystal are reported. Both, negative cascaded chi((2)) lensing and frequency doubling nonlinear mirror (FDNLM) are exploited for the laser mode-locking. The FDNLM based on intensity dependent reflection in the laser cavity ensures self-starting and self-sustaining mode-locking while the cascaded chi((2)) lens process contributes to substantial pulse shortening. This hybrid technique enables generation of stable trains of pulses at high-average output power with several picoseconds pulse width. The pulse repetition rate of the laser is 117 MHz with average output power ranging from 0.5 to 3.1 W and pulse duration from 2.9 to 5.2 ps.

1.34-μm Nd:YVO 4 laser mode-locked by SHG-lens formation in periodically-poled stoichiometric lithium tantalate

Self-starting, steady-state χ((2))-lens mode-locking of a 1.34-μm diode-pumped Nd:YVO(4) laser using intracavity second harmonic generation in PPMgSLT is demonstrated. Pulses as short as 3.6 ps with an average output power of ~1 W are obtained at a repetition rate of 120 MHz.

52-mJ, kHz-Nd:YAG laser with diffraction limited output

We present Nd:YAG, diode pumped amplifier system emitting up to 52-mJ pulse energy with 1.6-ns pulse duration and near diffraction limited beam, operating at 0.75-kHz repetition rate.

Passive mode-locking of a diode pumped Nd:ScYSiO 5 laser

In this work we report the first realisation of a Nd:ScYSiO5 laser mode-locked by semiconductor saturable absorber mirror (SESAM). We achieve a stable train of picosecond pulses having 5.7 ps pulse duration and average output power of 150 mW at repetition rate of 99 MHz, as well as dual-wavelength mode-locking with output power of 500 mW.

Nd:LuVO4 Laser Passively Mode-Locked by χ(2) -Lens Formation in Periodically-Poled Stoichiometric Lithium Tantalate

Stable mode-locking of a Nd:LuVO4 laser by intracavity second harmonic generation in PPMgSLT nonlinear crystal is demonstrated with maximum achieved average powers of 1.7 W and pulse durations as short as 3.4 ps.

Yb,Na:CaSrF 2 - A promising laser crystal medium in UV - VIS - Near-IR domain

The crystal CaF2 and its isotypes SrF2 and BaF2 doped with lanthanide elements, they are investigated for nonlinear optical applications and generation of ultrashort laser pulses. The Yb-doped crystal fluoride matrixes are could be also attractive for ICT, medical interventions, laser materials treatment, etc. The broad near-IR (NIR) luminescence in Yb3+ state (the second telecommunication window) and also their yellow-green and near-UV luminescence of Yb2+ are observed at low temperatures, although for the Yb,Na:CaSrF2 it is clearly observable at normal conditions. The Stokes fluorescence bands between 300 - 400 nm for the Yb,Na:CaSrF2 crystal medium induced from non-parametric processes in UV are narrow, clearly distinguishable and could be applied for novel lasers in UV - VIS range.

χ (2) -Lens mode-locking of a Nd:YVO 4 laser with high average power and repetition rate up to 600 MHz

We demonstrate χ⁽²⁾-lens mode-locking of a diode pumped Nd:YVO₄ laser. The output power is 6 W, the pulse duration is 6 ps for repetition rates from 110 MHz up to 600 MHz.

χ (2) -Lens Mode-Locking of a High Average Power Nd:YVO 4 Laser

We report over 20 W, 6 ps, 170 MHz, passive mode-locking of a Nd:YVO₄ laser using χ⁽²⁾-lens formation in a LBO frequency doubling crystal. The laser is pumped at 808 nm with optical efficiency of 38%.

1.34 μm Nd:YVO4 laser mode-locked by a single-walled carbon nanotube saturable absorber

Passive mode-locking of 1.3 μm solid-state lasers is problematic for semiconductor saturable absorber mirrors (SESAMs) not only because of difficulties in their fabrication process but also in relation to the achievable parameters and damage resistivity. In contrast, single-walled carbon nanotube saturable absorbers (SWCNT-SAs) exhibit broadband absorption which is controllable by varying the nanotube diameter and chirality, and require relatively simple manufacturing processes. Here we report on steady-state mode-locked operation of a diode pumped Nd:YVO4 laser on the 4F3/2→4I13/2 transition at 1.342 μm using a transmitting SWCNT-SA. The SWCNT-SA employed in the present work was fabricated by SWCNTs grown by high-pressure CO conversion technique, showing broad absorption around 1.3 μm. The linear transmission at the laser wavelength was about 99%. The Nd:YVO4 laser was longitudinally pumped by the unpolarized radiation of a 808 nm fiber-coupled laser diode. The ~1.2-m long cavity was optimized for large fundamental mode size. Above threshold the laser operated first in the CW mode, then had a range of Q-switched modelocked operation before reaching the regime of stable steady-state mode-locking. With an output coupler of 90% reflectivity, the average output power in the steady-state mode-locked regime reached 0.8 W at a slope efficiency of 14.5% with respect to the incident pump power. At a repetition rate of 127 MHz this corresponds to single pulse energy of 6.3 nJ. Such pulse energies are comparable to the best results obtained using SESAMs but the pulse duration of 16.5 ps measured in the present experiment is substantially shorter.