Xiaoxu Huang

Efficient and Compact Diode-Pumped Nd:YAG Lasers at 1073 and 1078 nm

We report on the efficient diode-pumped continuous-wave laser operation of a Nd:YAG crystal at several wavelengths by using a simple and compact two-mirror laser cavity and an undoped YAG thin plate acting as a Fabry-Pérot (F-P) etalon. We thus obtain a high-power single-wavelength laser operation at about 1073 nm with a maximum output power of 5.58 W and a laser slope efficiency of about 36.6%, with respect to absorbed pump power, which is believed to be the highest output power ever obtained with Nd:YAG at 1073 nm. We also achieve dual-wavelength laser operation at 1064 and 1078 nm, with a maximum output power of 1.57 W, and triwavelength laser operation at 1061, 1064, and 1078 nm, with a maximum output power of 2.16 W. This is the first demonstration, to the best of our knowledge, of a diode-pumped Nd:YAG laser at 1078 nm.

Watt-level narrow-linewidth Nd:YAG laser operating on 4 F 3/2 → 4 I 15/2 transition at 1834 nm

We report on a 808 nm diode-pumped Nd:YAG narrow linewidth laser at 1834.25 nm using a compact two-mirror linear cavity. In free-running mode, a maximum output power of 1.10 W is obtained with a slope efficiency of about 11.1% at a cooling temperature of the laser crystal of 18°C. Decreasing this temperature down to 8°C increases the output power linearly up to 1.31 W. Shortening the laser cavity reduces the output power down to about 0.70 W but on a single longitudinal mode. These laser results represent the best laser performance ever achieved with any Nd-doped bulk material in the 1.8 µm mid-infrared spectral range.

Single- and dual-wavelength lasers of diode-pumped Nd:LuYAG mixed crystal on various 4F3/2 → 4I13/2 Stark-level transitions

A diode-end-pumped Nd:LuYAG mixed crystal laser in the 1.3 μm spectral domain using a simple and compact two-mirror laser cavity is reported for the first time to our knowledge. In the free-running laser operation, we obtain a simultaneous dual-wavelength laser at about 1319 and 1338 nm with a maximum output power of 2.92 W and a slope efficiency of about 26.7%. By inserting an undoped YAG etalon into the laser cavity, the two 1319 and 1338 nm lasers can be operated singly with the maximum output powers of 1.36 and 1.73 W. Moreover, three simultaneous dual-wavelength lasers at 1334.67 and 1340.93 nm, 1319.15 and 1354.57 nm, and 1335.54 and 1354.94 nm can also be yielded with maximum output powers of 1.02, 0.66, and 0.47 W as well as slope efficiencies of 12.3%, 8.9%, and 6.9%, respectively. These dual-wavelength laser sources provide potential THz wave generation by beat frequency.

Full investigation into continuous-wave Nd:LuAG lasers on 4 F 3/2 → 4 I 13/2 transition around 1.3 and 1.4 μm

We report a full investigation of continuous-wave diode-pumped Nd:LuAG single crystal lasers on 4F3/2→4I13/2 transition around 1.3 and 1.4 μm. In free-running mode, a maximum output power of 4.18 W is achieved for a simultaneous dual-wavelength laser operation at 1321 and 1338 nm, which represents the highest output power for Nd:LuAG laser material at a 1.3 μm emission band. Three single wavelength lasers at 1340, 1332 and 1322 nm, as well as a dual-wavelength laser at 1334 and 1338 nm, are also generated with maximum output powers of 2.39, 2.63, 2.24 and 1.23 W, respectively, with the aid of a glass etalon. Moreover, a single wavelength laser at 1353 nm is also obtained with a maximum output power of 1.53 W. Furthermore, in free-running mode, simultaneous tri-wavelength eye-safe lasers at 1419, 1432 and 1442 nm are attained with a maximum output power of 1.83 W, and a 1.08 W single wavelength laser at 1419 nm is also yielded. Most of the 1.3 μm lasers and all of the 1.4 μm lasers are demonstrated for the first time to our knowledge. Thus, this work indicates that Nd:LuAG crystal is a very promising laser gain medium for high-power continuous-wave infrared laser generation.

Diode-pumped dual-wavelength Nd:LSO laser at 1059 and 1067 nm with nearly diffraction-limited beam quality.

We report a diode-pumped continuous-wave simultaneous dual-wavelength Nd:LSO laser at 1059 and 1067 nm. By employing a specially coated output coupler with relatively high transmissions at high-gain emission lines of 1075 and 1079 nm, the two low-gain emission lines, 1059 and 1067 nm, can be achieved, for the first time to our knowledge, with maximum output power of 1.27 W and slope efficiency of about 29.2%. The output power is only limited by the available pump power. Output beam quality is also measured to be about 1.19 and 1.21 of the beam propagation factors in the x and y directions, respectively.

Continuous-wave and passively Q-switched Tm 3+ -doped LuAG ceramic lasers

We report on diode-pumped continuous-wave Tm:LuAG ceramic laser with a maximum output power of 2.64 W and slope efficiency of about 35.6%. Using a Cr:ZnSe saturable absorber, we also operate the Tm:LuAG ceramic laser in passively Q-switched regime. A maximum average output power up to 1.06 W with a slope efficiency of 16.1% is achieved with a V-shaped laser resonator. The narrowest pulse width is measured to be about 277 ns and the maximum pulse energy is about 81.4 μJ.

Laser wavelength tunability of a diode-pumped Nd:LiYF4 laser on the 4F3/2–4I13/2 transition

Abstract We report a free-running orthogonally polarized dual-wavelength laser at 1313 and 1321 nm with maximum total output power of about 1.73 W using a two-mirror linear cavity. By inserting an etalon into the linear cavity, single-wavelength lasers at 1317 or 1323 nm, two-wavelength lasers at 1317 and 1323 nm, as well as four-wavelength lasers at 1313, 1317, 1323 and 1370 nm can be achieved with maximum output powers of about 0.73, 0.63, 0.78 and 0.25 W, respectively. About 10-nm wavelength tunability from about 1313 to 1323 nm is also realized by inserting the etalon into a three-mirror V-type Nd:YLF laser cavity.