123 research outputs found
Diode-pumped Nd:BaY(2)F(8) picosecond laser
No full textPicosecond pulse generation at 1050 nm by a diode-pumped Nd:BaY(2)F(8) (Nd:BaYF) active crystal has been investigated under low-power pumping (440 mW absorbed). The sample was oriented along the optical axes and cut at Brewster angle for y-axis laser polarization to minimize birefringence effects. Stable passive mode-locking operation has been achieved by inverse saturable absorption with 80-mW output power and 3.7-ps pulses. (C) 2008 Elsevier B.V. All rights reserved
150-μJ, 60-ns single longitudinal mode passively Q-Switched Nd:YAG ring laser oscillator with external feedback
No full textWe present a quasi-cw diode-pumped, Cr:YAG passively Q- Switched Nd:YAG ring laser. By employing an external feedback mirror to force unidirectional oscillation and a 103-GHz, low- finesse etalon, we obtained 150-μJ, 60-ns TEM00 single longitu- dinal mode laser pulses (13-MHz bandwidth) at a repetition rate selectable between 0.1 and 2 kHz
Multi-mJ, side-pumped, polarization coupled Nd:YAG Porro-prism laser in active and passive Q-switching regime
No full textWe present a Nd:YAG, diode-stack side-pumped, Porro-prism resonator. Laser performance was investigated both in Cr:YAG passive and KTP Pockels-cell active Q-Switching regimes. 10-mJ, 40-ns pulses were obtained at 20 Hz pulse-rate with M2<10 and low jitter. The misalignment insensitivity guaranteed by crossed- Porro-prisms design is attractive for applications in harsh envi- ronment
Femtosecond optical parametric oscillator with 3D-printed polymeric parts
No full textA synchronously-pumped optical parametric oscillator (SPOPO) based on a periodically-poled, MgO-doped lithium niobate (MgO:PPLN) crystal was realized exploiting additive manufacturing technology for the pump and focusing section of the cavity, where careful predesign of the tightly-packed mounts and optics can be very helpful in view of a more traditional mechanical realization. Surprisingly, the 3D-printed plastic parts ensured long-term stability of the (quite sensitive, in principle) femtosecond SPOPO
Jitter investigation of narrow-bandwidth passively Q-switched Nd:YAG unidirectional ring laser
No full textA passively Q-switched Nd:YAG undirectional ring laser with external feedback is reported. The laser generates 50 ns single-axial-mode pulses up to 6 kHz, with energy 34 mu J, M2 < 1.05, and pulse jitter <50 ns rms, which is quite remarkable for this class of devices. Jitter was effectively minimized by using relatively high-peak-power pump pulses of 10 W, in agreement with a model considering both pump fluctuations and spontaneous emission noise. This represents an improvement by a factor of 8 with respect to a similar laser device we recently reported
Picosecond Nd:BaY2F8 laser discretely tunable around 1 micron
No full textPassive mode-locking of a diode-pumped Nd:BaY(2)F(8) (Nd:BaYF) was achieved on four lines in the range 1040-1074 nm, employing a semiconductor saturable absorber mirror (SAM). Nearly Fourier-limited pulses with durations of 2.6 to 7.2 ps and output power a parts per thousand 50 mW were generated in a dispersion-controlled resonator using a single prism for wavelength selection, tuning and dispersion management
Low-jitter, narrow-bandwidth, single longitudinal mode passively Q-switched Nd:YAG ring laser oscillator with external feedback
No full textFourier-limited, also called single-frequency or single-longitudinal-mode (SLM) nanoseconds lasers at 1 μm are key elements for several applications, such as optical communications, data storage and high-resolution spectroscopy. Some special application such as high spectral resolution LIDAR, require very high spectral purity (tens of MHz bandwidth), resulting in long pulse durations in the range of several tens of ns. Microchip lasers with large free spectral range (FSR) comparable to the active medium gain bandwidth (about 160 GHz for Nd:YAG) allow easy SLM selection, but with much shorter pulses. Recently, we demonstrated a Cr:YAG Passively Q-Switched (PQS) Nd:YVO4 ring laser oscillator delivering 50-ns, 80-μJ SLM pulses at 0.1-10 kHz repetition rate employing a specifically designed intracavity etalon to enhance SLM operation. For SLM PQS operations, Nd:YAG offers some advantages if compared to Nd:YVO4. Namely, the higher saturation fluence relaxes the fulfilment of the second PQS threshold condition, the ~2 times longer fluorescence lifetime enhances energy storage and the narrower gain bandwidth favours SLM operation
Il ceto imprenditoriale nel primo decennio repubblicano. Anticipazioni su un campione di ricerca
No full textFerratini Tosi F., Grassi G., Legnani M., Maffeis M., Pirzio P., Zancanaro A. Il ceto imprenditoriale nel primo decennio repubblicano. Anticipazioni su un campione di ricerca. In: Mélanges de l'Ecole française de Rome. Moyen-Age, Temps modernes, tome 95, n°2. 1983. pp. 165-181
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