Unlocking superior performance of broadband powerful mid-IR optical parametric amplifiers with a BaGaGeS crystal pumped at 1.24 µm.

We report on the development of a tunable (1.5-6.5 µm) femtosecond optical parametric amplifier (OPA) based on a novel, to the best of our knowledge, BaGaGeS (BGGS) crystal with a Cr:Forsterite pumping laser.

Temperature-dependent phase-matching properties of BaGaGeS in the 0.767-10.5910  µm spectral range.

We report experimental results on the temperature-dependent phase-matching properties of for second-harmonic generation and sum-frequency generation in the 0.7674-10.5910 µm range.

Second-order nonlinear optical coefficients of the monoclinic crystal BaGaSe.

We characterize the magnitude and relative signs of the second-order nonlinear optical coefficients of the biaxial crystal BaGaSe (BGSe) combining measurements of phase-matched and non-phase-matched second-harmonic generation at different wavelengths using slabs and a sphere.

Few-cycle mid-infrared pulses from BaGaGeSe.

(BGGSe) is a newly developed nonlinear material that is attractive for ultrabroad frequency mixing and ultrashort pulse generation due to its comparably low dispersion and high damage threshold. A numerical study shows the material's capacity for octave-spanning mid-infrared pulse generation up to 18 µm. In a first experiment, we show that a long crystal length of 2.

Sum frequency generation of multi-line slab radio frequency discharge carbon monoxide laser system with intracavity nonlinear BaGaGeSe crystal.

A compact repetitively pulsed broadband carbon monoxide (CO) laser system with intracavity frequency conversion, for which a nonlinear crystal was also used as an output coupler, was launched for the first time, to the best of our knowledge. The laser system simultaneously operated in two spectral ranges: CO laser fundamental band (4.9-6.

Intracavity difference-frequency mixing of optical parametric oscillator signal and idler pulses in BaGaSe.

An overall quantum conversion efficiency of 7.8% is achieved by intracavity mixing the signal and idler of a 1.064 μm pumped Rb:PPKTP optical parametric oscillator in BaGaSe.

Widely tunable in the mid-IR BaGaSe optical parametric oscillator pumped at 1064  nm.

A BaGaSe nanosecond optical parametric oscillator (OPO) shows extremely wide idler tunability in the mid-IR (2.7-17 μm) under 1.064 μm pumping.

Phase-matching directions and refined Sellmeier equations of the monoclinic acentric crystal BaGaSe.

We directly measured the phase-matching directions of second-harmonic and difference frequency generation in the principal planes of the biaxial BaGaSe (BGSe) crystal using the sphere method. The simultaneous fit of the data allowed us to refine the Sellmeier equations of the three principal refractive indices of BGSe, and to calculate the tuning curves for infrared optical parametric generation.

Angle noncritical phase-matched second-harmonic generation in the monoclinic crystal BaGa₄Se₇.

We performed a complete study of angle noncritical phase-matched second-harmonic generation in BaGa4Se7 in the mid-infrared region. We measured the dielectric frame orientation and showed that it does not rotate as a function of wavelength. We determined the phase-matching wavelengths and the associated spectral and angular acceptances along the x and y axes of the dielectric frame.

Difference-frequency generation of ultrashort pulses in the mid-IR using Yb-fiber pump systems and AgGaSe(2).

We employ AgGaSe(2) for difference-frequency generation between signal and idler of synchronously-pumped picosecond / femtosecond OPOs at 80 / 53 MHz. Continuous tuning in the picosecond regime is achieved from 5 to 18 µm with average power of 140 mW at 6 µm. In the femtosecond regime the tunability extends from 5 to 17 µm with average power of 69 mW at 6 µm.

Mid-infrared rotated image singly resonant twisted rectangle optical parametric oscillator based on HgGa(2)S(4) pumped at 1064 nm.

We compare linear, planar ring, and rotated image singly resonant twisted rectangle (RISTRA) type nanosecond optical parametric oscillator cavities using HgGaS nonlinear crystal pumped by 8 ns pulses at 1064 nm from a low beam quality pump source. The input-output characteristics and the output idler beam quality at 6300 nm are compared for two values of the pump beam diameter presenting different cavity Fresnel numbers and magnitudes of the spatial walk-off effect due to birefringence. The RISTRA cavity ensures in all cases a circular output beam profile but is advantageous in terms of beam quality with respect to the planar ring only at a large pump beam diameter.

Narrow bandwidth, picosecond, 1064  nm pumped optical parametric generator for the mid-IR based on HgGa₂S₄.

We report on optical parametric generation in a mercury thiogallate (HgGa2S4) crystal pumped by 16 ps, 1064 nm pulses at 250 kHz. A broad tuning range extending from 1.19 to 1.

Dysprosium-doped PbGa2S4 laser generating at 4.3 μm directly pumped by 1.7 μm laser diode.

In this Letter, we demonstrate the pulsed and CW operation of the Dy:PbGa(2)S(4) laser directly pumped by the 1.7 μm laser diode. In the pulsed regime (pulse duration 5 ms; repetition rate 20 Hz), the maximum mean output power of 9.

Midinfrared optical parametric oscillator based on the wide-bandgap BaGa4S7 nonlinear crystal.

The orthorhombic biaxial crystal BaGa(4)S(7) has been employed in a 1064 nm pumped optical parametric oscillator generating <6 ns long idler pulses with energies as high as 0.5 mJ at 6.217 μm and average power of ~50 mW at 100 Hz.

Dysprosium-doped PbGa2S4 laser excited by diode-pumped Nd:YAG laser.

We realized a compact mid-IR room temperature operating Dy(3+):PbGa(2)S(4) laser, excited by a diode-pumped Nd:YAG laser at a wavelength of 1318 nm. The pumping laser was operating in pulsed mode with a pulse length of 4 ms and repetition rate of 20 Hz. Maximum pumping energy at a wavelength of 1318 nm was 15 mJ.

Oscillation properties of dysprosium-doped lead thiogallate crystal.

The room-temperature laser-oscillation properties of lead thiogallate crystals doped with dysprosium ions PbGa(2)S(4):Dy(3+) without additional codoping and codoped with potassium ion for excessive charge compensation were investigated. A slope efficiency of 1% was obtained for the codoped crystal. YAP:Er -1.

[24-Hour blood pressure profile in patients with mild and moderate arterial hypertension and sleep apnea/hypopnea].

Aim: To evaluate 24-hour blood pressure (BP) profile in arterial hypertension (AH) patients (pts) with desaturation signs of sleep apnea/hypopnea syndrome (SAHS).

Material And Methods: We investigated 61 pts (44 males and 17 females) aged between 23-70 (52 +/- 2) years with mild to moderate AH. BP monitoring was performed with multisensor system TM-2425 (A&D, Japan).