Laser spectrum of a high power Tm,Ho:GdVO<Subscript>4</Subscript> laser

In this paper, we report a 18.8 W continuous wave and 18.4 W Q-switched diode-pumped cryogenic Tm(5 at %), Ho(0.5 at %):GdVO₄ laser. The pumping source of Tm, Ho:GdVO₄ laser is a fiber-coupled laser diode with fiber core diameter of 0.4 mm, supplying 42 W power at 802.5 nm. For input pump power of 41.9 W at 802.4 nm, the output power of 18.8 W in CW operation, optical-to-optical conversion efficiency of 45% at 2.05 μm and the average output power of 18.4 W in Q-switched operation, optical-to-optical conversion efficiency of 44% at 2.04 and 2.05 μm have been attained. The emission wavelengths of the Tm(5 at %), Ho(0.5 at %):GdVO₄ laser were firstly compared when it worked in CW mode and Q-switched mode.     

High efficiency continuous-wave single-frequency Nd:YVO<Subscript>4</Subscript> ring laser under diode pumping at 880 nm

An efficient single-frequency continuous-wave Nd:YVO₄ ring laser pumped at 880 nm is presented. With compact four-mirror ring cavity and optical isolator, we obtained an output power of 14.56 W at 1064 nm, corresponding to a slope efficiency of 61.7% and an optical-to-optical efficiency of 58.4% with respect to the absorbed pump power. The stability of the output power was better than ±0.5% over two hours. At the same time, a beam quality factor of M ²≈1.2 was measured and the line width of the longitudinal mode was about 25 MHz. To the best of our knowledge, this is the highest slope efficiency and optical-to-optical efficiency in single-frequency Nd:YVO₄ ring laser.     

Continuous-wave intracavity frequency-doubled Nd:Yag-KTiOPO<Subscript>4</Subscript> red laser

Efficient and compact red laser output at 669 nm is generated by intracavity frequency doubling of a continuous-wave (CW) diode-pumped Nd:YAG laser at 1338 nm. With 16.9 W of diode pump power and the frequency-doubling crystal KTiOPO₄ (KTP), a maximum output power of 582 mW in the red spectral range at 669 nm has been achieved, corresponding to an optical-to-optical conversion efficiency of 3.4%; the output power stability over 4 h is better than 3.6%. To the best of our knowledge, this is first work on intracavity frequency doubling of a diode pumped Nd:YAG laser at 669 nm.     

Efficiency intracavity frequency-doubled Nd:Y<Subscript>0.36</Subscript>Gd<Subscript>0.64</Subscript>VO<Subscript>4</Subscript>-LBO green laser at 532 nm with direct pumping

We report an efficient laser emission on the 1064 nm ⁴ F _3/2 to ⁴ I _11/2 transition in mixed vanadate crystal Nd:Y_0.36Gd_0.64VO₄ under the pump with diode laser at 880 nm. Continuous wave (CW) 10.7 W output power at 1064 nm is obtained under 17.8 W of incident pump power; the slope efficiency with respect to the incident pump power was 71.2%. Moreover, intracavity frequency doubling with LiB₃O₅ (LBO) nonlinear crystal yielded 4.6 W of green light at 532 nm. An optical-to-optical efficiency with respect to the incident pump power was 25.8%.     

Power scaling of a continuous-wave and passively Q-switched Yb:KLu(WO<Subscript>4</Subscript>)<Subscript>2</Subscript> laser end-pumped by a high-power diode

The power scaling capacity of a diode end-pumped Yb:KLu(WO₄)₂ laser, operating in the continuous-wave (cw) and passively Q-switched regimes, has been investigated. A cw output power of 11.5 W was achieved with an optical-to-optical efficiency of 41% with respect to the incident pump power, while the slope efficiency amounts to 60%. The passively Q-switchedoperation yielded an average output power of 4.3 W at the fundamental wavelength of 1031.7 nm, and 1.15 W of Raman radiation at 1139.3 nm. The total slope efficiency for Q-switched operation was 40%. The highest pulse energy, duration, and peak power were 170 μJ, 2.2 ns, and 77.3 kW for the fundamental radiation, and 51 μJ, 2.3 ns, and 22.2 kW for the Raman radiation. PACS 42.55.Rz; 42.55.Xi; 42.55.Ye     

Compact TEM<Subscript>00</Subscript> grazing-incidence Nd:GdVO<Subscript>4</Subscript> laser using a folded cavity

A compact diode-side-pumped Nd:GdVO₄ laser system using a folded cavity and grazing-incidence configuration is presented. The highest multimode output power obtained was 21.8 W at 36 W of effective diode pump power. Highest optical-to-optical conversion efficiency of 61.5% was achieved at 33 W of effective diode pump power with 20.3 W of multimode output power. For single-mode TEM₀₀ operation, an intracavity telescope was adopted for mode matching in the horizontal direction. Because of the folded cavity and the intracavity telescope, this laser head was the most compact to our knowledge of the TEM₀₀ grazing-incidence laser geometry. At last, an output power of 15 W was produced at 36 W of effective diode pump power. The stable Q-switching operation was also obtained. PACS 42.55.-f; 42.55.Xi; 42.60.Gd     

A high power CW Ho,Tm:GdVO<Subscript>4</Subscript> laser

In this paper, we report a 22.7 W continuous wave (CW) diode-pumped cryogenic Ho( at %), Tm(3 at %):GdVO₄ laser. The pumping sources of Ho,Tm:GdVO₄ laser are two fiber-coupled laser diodes with fiber core diameter of 0.4 mm, both of them can supply 42 W power laser operating near 802 nm. For input pump power of 64.7 W at 802.5 nm, the output power of 22.7 W in CW operation, optical-to-optical conversion efficiency of 35.1% at 2.05 μm has been attained. The M ² factor was found to be 2.0 under an output power of 16.5 W.     

Study of LD pumped Q-switched Nd:Y<Subscript>0.5</Subscript>Lu<Subscript>0.5</Subscript>VO<Subscript>4</Subscript> laser with acousto-optic modulator

A laser-diode (LD) pumped Q-switched Nd:Y_0.5Lu_0.5VO₄ crystal laser with an acousto-optic (AO) modulator is presented in this paper. The maximum continuous wave (CW) output power of 5.53 W is achieved at the incident pump power of 14.09 W with the transmission of 10% for the output coupler, resulting in an optical-to-optical conversion efficiency of 39.2%. For Q-switching operation, the shortest pulse width of 8.3 ns and the highest peak power of 259 kW are generated under the incident pump power of 14.09 W at 1 kHz.     

CW Nd:LuVO<Subscript>4</Subscript>-GdCa<Subscript>4</Subscript>O(BO<Subscript>3</Subscript>)<Subscript>3</Subscript> red laser under direct 888 nm pumping

We report a red laser at 672 nm generation by intracavity frequency doubling of a continuous wave (CW) laser operation of a 1343 nm Nd:LuVO₄ laser under in-band diode pumping at 888 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 1.73 W of CW output power at 672 nm is achieved. The optical-to-optical conversion efficiency is up to 9.7%, and the fluctuation of the red output power was better than 3.3% in the given 30 min.     

All-solid-state CW Nd:LuVO<Subscript>4</Subscript>-LBO laser at 533 nm under direct 888 nm pumping

We report an efficient laser emission on the 1066 nm ⁴ F _3/2 to ⁴ I _11/2 transition in Nd:LuVO₄ under the pump with diode laser at 888 nm. Continuous wave (CW) 11.2 W output power at 1066 nm is obtained under 18.3 W of incident pump power; the slope efficiency with respect to the incident pump power was 71.9%. Moreover, intracavity frequency doubling with LiB₃O₅ (LBO) nonlinear crystal yielded 4.2 W of green light at 533 nm. An optical-to-optical efficiency with respect to the incident pump power was 23.0%.     

All-solid-state intracavity frequency-doubled Nd:Y<Subscript>0.36</Subscript>Gd<Subscript>0.64</Subscript>VO<Subscript>4</Subscript>-GdCa<Subscript>4</Subscript>O(BO<Subscript>3</Subscript>)<Subscript>3</Subscript> 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:Y_0.36Gd_0.64VO₄ 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.     

High efficiency passive mode-locked Nd:YVO<Subscript>4</Subscript> laser based on SESAM under direct pumping at 880 nm

We report on an 880 nm LD pumped passive mode-locked TEM₀₀ Nd:YVO₄ laser based on a semiconductor saturable absorber mirror (SESAM), with a high optical-to-optical conversion efficiency of 67.3%, and a slope efficiency of 71%. When the absorbed pump power was 11 W, 7.4 W average output power of 1064 nm continuous-wave mode-locked laser was achieved. To our knowledge, this is the highest optical-to-optical conversion efficiency among all the published reports of 880 nm LD pumped SESAM passive mode-locked lasers. The repetition rate of mode-locked pulse was 80 MHz with 26 ps pulse width. The maximum pulse energy and peak power were 92.5 nJ and 3.6 kW, respectively.     

Efficient Nd:Y<Subscript>0.36</Subscript>Gd<Subscript>0.64</Subscript>VO<Subscript>4</Subscript>-GdCa<Subscript>4</Subscript>O(BO<Subscript>3</Subscript>)<Subscript>3</Subscript> 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:Y_0.36Gd_0.64VO₄ laser under diode pumping into the emitting level ⁴ F _3/2. 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.     

880 nm laser-diode end-pumped Nd:YVO<Subscript>4</Subscript> slab laser at 1342 nm

43.6 W near-diffraction-limited continuous-wave laser beam at 1342 nm in 880 nm laser-diode partially end-pumped Nd:YVO₄ slab laser is presented. The slope efficiency and optical-to-optical efficiency with respect to absorbed pumping power were 45.4% and 35.9%, respectively. At output power of 34.5 W, the M ² factors in unstable and stable directions were 1.3 and 1.2, respectively.     

All-solid-state Nd:YVO<Subscript>4</Subscript> laser at 1342 nm under 914 nm diode laser pumping

A Nd:YVO₄ crystal was pumped directly into the emitting level by a laser diode at 914 nm. We achieved an output power of 1.46 W at 1342 nm for an incident pump power of 18.3 W, corresponding to an optical-to-optical conversion efficiency of 8.0%. The fluctuation of the output power was better than 2.3% in the given 30 min. The beam quality M₂ factor value was equal to 1.15 at the maximum output power.     

Diode pumped Nd:Lu<Subscript>0.5</Subscript>Y<Subscript>0.5</Subscript>VO<Subscript>4</Subscript>-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:Lu_0.5Y_0.5VO₄ laser on the ⁴ F _3/2-⁴ I _13/2 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.     

Study of Yb:YVO<Subscript>4</Subscript> lasers end-pumped by a 985-nm diode laser

Efficient continuous-wave operation is demonstrated at room temperature with a Yb:YVO₄ laser end pumped by a 985-nm diode. An output power of 2.46 W is generated at the highest available absorbed pump power of 6.2 W, with an optical-to-optical and slope efficiency of 40 and 76%, respectively. A theoretical calculation of the laser characteristics agrees closely with the experimental results.     

All-solid-state CW frequency-doubling Nd:LuVO<Subscript>4</Subscript>/KTP laser with 2.3 W output power at 545 nm

Efficient and compact green-yellow laser output at 545 nm is generated by intracavity frequency doubling of a continuous-wave (CW) diode-pumped Nd:LuVO₄ laser at 1089 nm under the condition of suppressing the higher gain transition near 1066 nm. With 18.7 W of diode pump power and the frequency-doubling crystal KTiOPO₄(KTP), as high as 2.3 W of CW output power at 545 nm is achieved, corresponding to an optical-to-optical conversion efficiency of 12.3%; the output power stability over 4 h is better than 5.4%.     

A high beam quality laser-diode end-pumped Nd:GdVO<Subscript>4</Subscript> slab laser

An 83 W, near-diffraction-limited LD end-pumped Nd:GdVO₄ slab laser with hybrid resonator was presented with the pumping power of 238 W, the slope efficiency and optical-to-optical conversion efficiency were 39.4 and 34.9%, respectively. At the output power of 70 W, beam quality M² factors were 1.2 in stable direction and 1.3 in unstable direction.     

All solid-state CW Nd:LuVO<Subscript>4</Subscript>-LBO yellow-green laser under direct 888 nm pumping

We report a yellow-green laser at 544.5 nm generation by intracavity frequency doubling of a continuous wave (CW) laser operation of a 1089 nm Nd:LuVO₄ laser under in-band diode pumping at 888 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 17.9 W, as high as 3.81 W of CW output power at 544.5 nm is achieved. The optical-to-optical conversion efficiency is up to 21.3%, and the fluctuation of the yellow-green output power was better than 3.7% in the given 4 h.