Q-switched mode locking with acousto-optic modulator in a diode-pumped Nd:YVO4 laser

Abstract

The Q-Switched Mode Locking (QML) regime provides the generation of relatively high peak power picosecond pulses train with energies of a few muJ each in a simple resonator. The fully modulated efficient QML regime was demonstrated in the diode-pumped Nd:YVO4 laser. The acousto-optic cell playing a double role of Q-switch and Mode Locker was located near flat output coupler. The two folding mirrors were mounted on the translation stages for matching the resonance frequency of the cavity to the radio frequency of acousto-optic modulator. The QML pulses with envelope durations of 100-150 ns and near 100% modulation depth were observed for wide range of pump powers and repetition rates. Up to 3 W of output average power, 100 muJ of the envelope energy, having approximately 5-8 mode-locked pulses were achieved.

Mode-Locked Fibre Lasers with High-Energy Pulses

“…In order to radically boost the pulse energy, additional optical amplifiers were used or, otherwise, a completely different method of short pulse generation, Q-switch was employed, which allowed considerably higher per-pulse energy, albeit at the expense of longer duration, typically, over several nanoseconds and more. The combined Q-switching and mode locking in one cavity has also been successfully employed for generation of high-energy pulses of laser radiation (Lin et al 2008, Jabczyński et al, 2006. Another way to increase per-pulse energy of output radiation is the cavity dumping technique (Johnson et al, 1976), which can be used in all the mentioned above types of lasers.…”

Actively Q-switched and modelocked all-fiber lasers

“…Their unique characteristics of high intensities together with relatively low heat deposition ensure precise removal of material during a short interaction time [1]. Among the methods developed to generate these pulses [1][2][3][4][5][6][7][8][9], it was proposed the Q-switching mode-locking technique (QML). It consists in the simultaneous generation of Qswitching [10] and mode-locking (ML) [11] in the same cavity.…”

Diode-pumped actively Q-switching and mode-locking Nd:GdVO4laser

“…All the comparisons indicate that, Nd:GdVO 4 is more competent than Nd:YVO 4 when operated in mode locked state. Up to now, actively QML has been achieved in some neodymium ion hosted crystals, such as Nd:YVO 4 [7,8] and the actively QML green lasers with KTP frequency crystal have been reported in our earlier work [16].…”