Compact, diode-side-pumped and Q-switched Nd:YLiF4 laser cavity operating at 1053 nm with diffraction limited beam quality

Abstract

This work reports a diode-side-pumped and passively Q-switched Nd:YLiF 4 (YLF) laser operating at 1053 nm using a new laser resonator concept. Very stable pulses of 1 mJ energy with less than 10 ns pulse duration are obtained at 1 kHz repetition rate in a very simple, compact, and robust cavity that uses a double bounce configuration to achieve TEM 00 operation.To obtain high power, short Q-switched pulses of the order of 10 ns, diffraction limited beam quality and high repetition rates is still a major goal in laser cavity design. A great number of industrial, environmental, and scientific applications would certainly benefit from a laser cavity design that provides these characteristics at reduced complexity and costs. Whilst high power is supplied by simple lamp pumped designs, they generally cannot deliver the high repetition rates (>30 Hz) and good beam quality. On the other hand, QCW diodes can operate with typical duty cycles of 5% which allow, in principal, repetition rates of several kHz. The directional emission of the laser diode allows for tight focusing and spatially matching with the TEM 00 resonator mode, thereby permitting for diffraction limited output. When diode-pumping is used in combination with active Q-switching, the timing jitter between pulses can be made less than the short pulse duration which is an essential advantage to many applications. Saturable absorber

Power scaling of a side-pumped Nd:YLF laser based on DBMC technology

“…As stated in the introductory part and explained in detail in References [5,9,15], the gain competition between the two near-parallel beams inside the slab, necessary for TEM 00 mode operation, is controlled primarily by the adjustment of the distance D between both beams (see Fig. 1).…”

“…Several different solid-state laser host materials [2][3][4][5] are capable of delivering efficient laser action of which YLiF4 (YLF) has some unsurpassed characteristics that are vital to many applications. In particular, the weak thermal lensing, natural birefringence, and long upper-laser-level lifetime are important for good beam quality and many applications such as Q-switching [6][7][8][9]. Moreover, the emission line at 1053 nm is of great interest for master oscillators of Nd:glass amplifiers [10].…”

Diode side pumped, quasi-CW Nd:YVO4self-Raman laser operating at 1176 nm

“…An attractive configuration is a side-pumping scheme with single or double beam (DBMC) technology, in which the laser beam performs a total internal reflection at the pumped facet of the crystal [16][17][18][19] . This geometry has shown high output powers at 1064 nm and a slope efficiency of 74% using a Nd:YVO 4 crystal 20,21 .…”

Compact high-pulse-energy passively Q-switched Nd:YLF laser with an ultra-low-magnification unstable resonator: application for efficient optical parametric oscillator

“…Compared to the mostly used Nd:YAG and Nd:YVO 4 crystals, the Nd:YLF crystal having the advantage of longer lifetime is more suitable for high-pulseenergy Q-switched lasers [5,6]. Furthermore, the uniaxial Nd:YLF crystal has two principal lasing transitions at 1047 nm (π) and at 1053 nm (σ), corresponding to the polarizations parallel and perpendicular to the crystal c-axis, respectively [7][8][9]. The 1047-nm and 1053-nm emissions are of great interest in the skin wound healing [10] and the Nd:glass amplification [11], respectively.…”