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Special Issue on Solid State Lasers Materials, Technologies and Applications
No full textEven though more than half a century has already passed since the first demonstration of laser action in ruby crystal, solid-state lasers are still a hot research topic.[...
Neodymium-doped yttrium aluminum garnet (Nd: YAG) and neodymium-doped yttrium orthovanadate (Nd: YVO4)
No full textIn this chapter we review the history of neodymium-doped
diode-pumped solid-state lasers (DPSSLs), since the first successful concepts exploited for industrial applications until the most recent state of-the-art solutions. We also discuss the major issues related to power or energy scaling of DPSSLs and some representative examples of design solutions proposed to overcome such limitations. The most recent exciting developments that promise further power and brightness upscaling through the affirmation of new laser materials and laser architectures are also presented
Low-threshold femtosecond Nd:glass laser
No full textUsing a 150-mW single-transverse-mode laser diode at 802 nm
for pumping an Nd:phosphate laser, we achieved efficient cw operation
(40% slope efficiency) with pump threshold as low as 12 mW at optimum coupling, and a maximum output power of 53 mW. Under passive modelocking operation, we obtained nearly Fourier-limited 270-fs pulses in a prismless dispersion-compensated cavity and 173-fs pulses with a single-prism setup. This compact laser is especially interesting for applications requiring low power levels, such as seeding amplifiers and for biodiagnostics
Compact femtosecond Nd:phosphate prismless oscillator pumped by a single-mode 150-mW laser diode
No full textWe present a compact, passively mode-locked and prismless Nd:phosphate laser, pumped by a single-mode, low-power (150-mW) laser diode. We obtained self-starting 270-fs near transform-limited pulses, employing a single Gires-Tournois mirror for intracavity dispersion compensation
High gain solid-state modules for picosecond pulses amplification
No full textWe present both numerical models and experimental results of ultra-short pulses solid-state laser grazing-incidence amplifier modules for generation of intense picosecond pulses, in various regimes from single shot to repetition rates of GHz
High gain solid-state amplifiers for picosecond pulses
No full textWe review solid-state laser amplifiers for generation of intense picosecond pulses, in various regimes from single shot to repetition rates of GHz. Such laser sources are becoming increasingly attractive for many industrial and scientific applications. In particular, we have exploited the technology of side-pumped grazing-incidence bounce amplifiers. Such amplifiers yield very high gain per pass, up to several thousands, and offer excellent beam quality preservation owing to the total reflection leading to left-right inversion. This technology allows the realization of compact, efficient and modular amplifiers, significantly simpler than, for example, cavity-based regenerative schemes.
Starting from robust, low-power diode-pumped solid-state oscillators, using programmable pulse-pickers one can select either a single pulse or a properly shaped pulse train for further amplification and compensation of envelope distortions due to gain saturation.
For single pulse amplification it is preferred to start with a relatively low-repetition-rate oscillator (< 100 MHz). Picosecond fiber oscillators are most promising in this respect.
Using quasi-cw diode arrays as the pump source of Nd:YVO4 slab amplifier, starting from ≈ 1 nJ, 10-ps pulse seed, amplified pulse energy as high as 200 μJ at 1 kHz can be obtained. Efficient harmonic and traveling-wave parametric generation are readily achieved with such high pulse peak powers.
Some other applications require instead the amplification of pulse trains, that can be conveniently extracted and amplified from a low-power oscillator at the desired repetition rate. For example, starting from a 20-mW, 5-GHz picosecond oscillator we amplified trains of few thousands of pulses up to 2 mJ with three slab amplifiers (as much as 300 mJ were achieved with two additional Nd:YAG flash-lamp-pumped post-amplifiers). Such pulse trains are very effective for synchronous pumping of optical parametric oscillators, lowering significantly their threshold with respect to the traveling-wave geometry.
When multi-MHz picosecond pulses are required, cw diode arrays are chosen as pump sources for the slab amplifiers. An 8-W, 8-ps laser system has been demonstrated starting from a 50-mW cw oscillator, at 150 MHz. Owing to the effective gain shaping of the tightly pumped amplifier, no significant thermal distortion were detected, allowing nearly diffraction limited operation. Although high power picosecond oscillators have been demonstrated lately, this result is interesting since it suggests an alternative way for power-scaling of picosecond sources without pushing delicate intracavity components (such as semiconductor saturable absorbers) to the damage limit.
Numerical models of the amplifiers and their dynamics are also reviewed. The effects of amplified spontaneous emission are discussed, as well as the most effective methods for its suppression
Compact sub-100-fs Nd:silicate laser
No full textWe present a compact Nd:silicate laser pumped by a single 1-W high-brightness commercial laser diode that generates pulses as short as 88 fs (nearly Fourier limited) when passively mode-locked with a saturable absorber mirror. We also tested a prismless cavity setup employing a single Gires–Tournois mirror, yielding 100-fs pulses. These setups are significantly simpler and more compact than those reported previously for short pulse Nd:silicate lasers
Sub-nanosecond single-frequency 10-kHz diode-pumped MOPA laser
No full textA single-axial-mode, passively Q-switched (PQS) diode-pumped Nd:YAG laser, generating a diffraction- limited beam train of ≈40–60 μJ, ∼500-ps pulses with adjustable repetition rate in the range 1–10 kHz, was effi- ciently amplified by a single side-pumped Nd:YVO4 bounce amplifier. After double-pass amplification, ≈1-MW pulse peak power with 577-ps duration and 545-μJ energy was achieved, still maintaining diffraction-limited beam perfor- mance. The average output power was 5.45 W at 10 kHz, corresponding to 13% extraction efficiency. The high bright- ness of this laser system seems ideal for nonlinear optics and some particular laser processing applications
Femtosecond Nd:glass oscillator operating in normal dispersion regime
No full textA diode-pumped, prismless Nd:glass laser oscillator, modelocked
by a semiconductor saturable absorber, was stabilized against self-Q-switching by using a phase-mismatched second harmonic crystal. Furthermore, negative-index cascaded second-order nonlinearity provided the soliton shaping mechanism with normal intracavity dispersion. Nearly Fourier-limited pulses as short as 520 fs were obtained
Multi-GHz tunable-repetition-rate mode-locked Nd:GdVO4 laser
Full text linkWe report on a simple design for a multi-GHz tunablerepetition-
rate diode-pumped picosecond laser. Using a plano-Brewster
Nd:GdVO4 crystal in a V-folded cavity employing only readily available commercial components, we achieved passive mode-locking with 4.4-ps pulses tunable in the range 2.5-2.7 GHz. This laser is meant to be employed in the MIR experiment that aims at the detection of the Schwinger radiation (dynamical Casimir effect)
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