Y. L. Li

Characterization of temporal pulse broadening for horizontal propagation in strong anisotropic atmospheric turbulence

The on-axis two-frequency mutual coherence function (MCF) for beam waves propagating along a horizontal path in strong anisotropic atmospheric turbulence is theoretically formulated by making use of the extended Huygens-Fresnel principle. Based on this formulation, a new closed-form expression for the mean square temporal width of Gaussian-beam-wave pulses passing horizontally through strong anisotropic atmospheric turbulence is developed. With the help of this expression, the increments of mean square temporal pulse width due to strong anisotropic atmospheric turbulence under various conditions are further calculated. Results show that the increment of mean square temporal pulse width due to strong anisotropic atmospheric turbulence is basically proportional to the effective anisotropic factor in most situations of interest, with the possible exception of cases in which both the Fresnel ratio and spectral index become relatively small; increasing the effective anisotropic factor can reduce the number of the said exceptions; the turbulence-induced increment of mean square temporal pulse width enlarges as the spectral index increases with a fixed value of the nondimensional turbulence-strength parameter. It is also illustrated that a significant enlargement in the turbulence-induced increment of mean square temporal pulse width occurs by changing the Fresnel ratio from a large to a tiny value if both the effective anisotropic factor and spectral index are relatively small.

High efficiency 1341 nm Nd:GdVO4 laser in-band pumped at 912 nm

A high-efficiency 1341 nm Nd:GdVO4 laser in-band pumped at 912 nm is demonstrated for the first time. Using an all-solid-state Nd:GdVO4 laser operating at 912 nm as pump source, 542 mW output was obtained with 1.14 W absorbed pump power. The slope efficiency with respect to the absorbed pump power was 56.6%, and the fluctuation of the output power was better than 2.6% in the given 30 min. The beam quality factor M2 is 1.15.

555 nm laser sources based on intracavity frequency doubling of Nd:YGG laser

We report for the first time a yellow-green laser at 555 nm generation by intracavity frequency doubling of a continuous wave (CW) laser operation of a 1110 nm Nd-doped yttrium gallium garnet (Nd:YGG) laser under in-band diode pumping at 808 nm. An LBO crystal, cut for critical type I phase matching is used for second harmonic generation of the laser. At an incident pump power of 18.5 W, as high as 2.31 W of CW output power at 555 nm is achieved. The optical-to-optical conversion efficiency is up to 12.4%, and the fluctuation of the yellow-green output power was better than 2.8% in the given 4 h.

All-solid-state intracavity frequency-doubled Nd:Y0.36Gd0.64VO4-GdCa4O(BO3)3 green laser under direct 880 nm pumping

We report a green laser at 532 nm generation by intracavity frequency doubling of a continuous wave (CW) laser operation of a 1064 nm Nd:Y0.36Gd0.64VO4 laser under in-band diode pumping at 880 nm. An GdCa4O(BO3)3 (GdCOB) crystal, cut for critical type I phase matching at room temperature is used for second harmonic generation of the laser. At an incident pump power of 17.8 W, as high as 2.92 W of CW output power at 532 nm is achieved. The optical-to-optical conversion efficiency is up to 16.4%, and the fluctuation of the green output power was better than 2.5% in the given 30 min.

All-solid-state CW intracavity frequency-doubling Nd:Lu2O3/LBO red laser at 679.5 nm

We report an efficient intracavity second-harmonic generation (SHG) at 1359 nm in a non-linear optical crystal, LiB3O5 (LBO), performed with a diode end pumped continuous-wave (cw) Nd:Lu2O3 laser. In the case of a laser with a Nd:Lu2O3 crystal frequency-doubled with a LBO crystal cut for type I frequency doubling. A cw SHG output power of 462 mW has been obtained using a 10 mm long LBO crystal. The red power stability was 3.4% in 4 h.

Efficient Nd:Y0.36Gd0.64VO4-GdCa4O(BO3)3 red laser under diode pumping into the emitting level

We report a red laser at 671 nm generation by intracavity frequency doubling of a continuous wave (cw) laser operation of a 1342 nm Nd:Y0.36Gd0.64VO4 laser under diode pumping into the emitting level 4F3/2. An GdCa4O(BO3)3 (GdCOB) crystal, cut for critical type I phase matching at room temperature is used for second harmonic generation of the laser. At an incident pump power of 17.8 W, as high as 1.12 W of cw output power at 671 nm is achieved. The optical-to-optical conversion efficiency is up to 6.3%, and the fluctuation of the red output power was better than 3.5% in the given 30 min.

Diode pumped Nd:Lu0.5Y0.5VO4-LBO red laser at 671 nm

We report a efficient compact red laser at 671 nm generation by intracavity frequency doubling of a continuous wave laser operation of a diode pumped Nd:Lu0.5Y0.5VO4 laser on the 4F3/2-4I13/2 transition at 1342 nm. An LBO crystal, cut for critical type I phase matching at room temperature is used for second harmonic generation of the laser. At an absorbed pump power of 17.8 W, as high as 2.25 W of continuous wave output power at 671 nm is achieved with 10-mm-long LBO. The optical-to-optical conversion efficiency is up to 12.6%, and the fluctuation of the red output power was better than 3.6% in the given 30 min.

Diode-pumped Nd:YGG continuous-wave laser at 1.33 μm

We demonstrated a laser-diode pumped Nd-doped yttrium gallium garnet (Nd:YGG) crystal continuous wave (CW) laser at 1.33 μm for the first time to our knowledge. At an incident pump power of 18.5 W, as high as 3.09 W of CW output power at 1.33 μm is achieved. The slope efficiency with respect to the incident pump power was 21.3%, and the fluctuation of the output power was better than 2.8% in the given 4 h. The beam quality factor M2 is 1.14 and 1.16 for tangential direction and sagittal direction, respectively.