Diode-pumped green Nd:YAG laser with Q-switch and mode locking

Abstract

We propose a new method for achieving simultaneous operation of laser mode locking and the Q-switch technique using only a single acousto-optic modulator (AOM) with a traveling wave; this AOM was placed inside the cavity of a green-emission Nd:YAG laser. The further shortening of the lasing pulse duration from 40 ps to less than 3.25 ps was obtained by the formation of a Kerr lens in a doubling-frequency crystal. At average output power of 1.5 W and pulse repetition rate of the Q-switch equal to 2 kHz, the peak power in a steady-operating laser exceeded 50 MW.

Geometrical analysis of Kerr-lens mode-locking for high-peak-power ultrafast oscillators

“…This analysis provided the detailed guideline needed to achieve soft-aperture KLM in ring resonators as described above: (i)-(iii). Our analytical approach can be used in recently developed high-power oscillators [6][7][8]11], new KLM-resonator designs [35,36], intracavity high harmonic generation [37], and for understanding the intracavity dynamics of KLM. Furthermore, more realistic analysis can be demonstrated by including thermal-lensing and the gain-guiding effect inside a gain medium.…”

“…( 5) has difficulty with multivariable analysis, because both 𝜔 and 𝜔 depend on intracavity parameters and peak power. Earlier works demonstrated KLM analysis based on only a single variable, such as 𝐾, 𝑧, or 𝑥 [10,11,16,29]. For multivariable analysis, we modify Eq.…”

“…where 𝜔(𝑃) is the spot size at the Kerr medium as a function of the intracavity power, 𝑃. Until now, the 𝛿 parameter was mostly used to design and analyze typical KLM resonators and to experimentally find the optimal conditions [8,[11][12][13]. This framework led to detailed KLM analyses of commonly used linear or ring resonators [14][15][16][17][18][19].…”

“…ω(P) is the spot size at the Kerr medium as a function of the intracavity power, P. So far, the δ parameter has been mostly used as a measure of stability to provide the basic guidelines for KLM in the commonly-used linear or ring resonators, and to design these resonators. [8][9][10][11][12][13][14] Although the more realistic frameworks which treat the spatiotemporal dynamics have been developed, 15,16) the analysis based on the δ parameter is still widely used [17][18][19][20][21] due to its simplicity and low cost of computation. However, the δ parameter is not always valid when the intracavity power P is close to or larger than the critical power for self-focusing, P c , defined as…”

Superluminescent high-efficient parametric generation in PPLN crystal with pumping by a Q-switched mode locked Nd:YAG laser

“…Figure 1 shows a diagram of the experimental setup for the parametric source without a resonator. Pumping laser 1 is a Nd:YAG laser with the assembly scheme [10,11]. The QML regime was achieved using a spherical mirror in the laser resonator and optoacoustic modulator of the running wave; the modulator was placed into the curvature center of the mirror.…”