Diode-pumped CW Nd:YAG laser at 1116 nm based on the <Superscript>4</Superscript><Emphasis Type="Italic">F</Emphasis><Subscript>3/2</Subscript>-<Superscript>4</Superscript><Emphasis Type="Italic">I</Emphasis><Subscript>11/2</Subscript> transition

We describe the output performances of the 1116 nm ⁴ F _3/2-⁴ I _11/2 transition (generally used for a 1064 nm transition) in Nd:YAG under in-band pumping with diode laser at the 809 nm wavelength. An end-pumped Nd:YAG crystal yielded 680 mW of continuous-wave (CW) output power for 18.2 W of incident pump power. Moreover, intracavity second-harmonic generation (SHG) has also been achieved with a power of 97 mW at 558 nm by using a LiB₃O₅ (LBO) nonlinear crystal. The yellow-green beam quality factor M ² was less than 1.21. The yellow-green power stability was less 2.5% in 4 h.     

Diode-pumped CW Nd:YAG laser at 1356 nm based on the <Superscript>4</Superscript><Emphasis Type="Italic">F</Emphasis><Subscript>3/2</Subscript>-<Superscript>4</Superscript><Emphasis Type="Italic">I</Emphasis><Subscript>13/2</Subscript> transition

We describe the output performances of the 1356 nm ⁴ F _3/2-⁴ I _13/2 transition (generally used for a 1319 nm transition) in Nd:YAG under in-band pumping with diode laser at the 809 nm wavelength. An end-pumped Nd:YAG crystal yielded 1.02 W of continuous-wave (CW) output power for 18.2 W of incident pump power. Moreover, intracavity second-harmonic generation (SHG) has also been achieved with a power of 290 mW at 678 nm by using a LiB₃O₅ (LBO) nonlinear crystal. The red beam quality factor M ₂ was less than 1.37. The red power stability was less 3.2% in 4 h.     

Diode-pumped Nd:LuVO<Subscript>4</Subscript>-Nd:YVO<Subscript>4</Subscript> laser at 492 nm with intracavity sum-frequency-mixing in LiB<Subscript>3</Subscript>O<Subscript>6</Subscript>

We present for the first time a Nd:YVO₄ laser emitting at 1064 nm intracavity pumped by a 916 nm diode-pumped Nd:LuVO₄ laser. A 809 nm laser diode is used to pump the Nd:LuVO₄ crystal emitting at 916 nm, a Nd:YVO₄ laser crystal was pumped at 916 nm and lased at 1064 nm. Intracavity sum-frequency mixing at 916 and 1064 nm was then realized in a LiB₃O₆ (LBO) crystal to reach the blue range. We obtained a continuous-wave output power of 216 mW at 492 nm under 19.6 W of incident pump power at 809 nm.     

Crystal growth,spectroscopic and CW laser properties of Nd<Subscript>0.03</Subscript>Lu<Subscript>2.871</Subscript>Gd<Subscript>0.099</Subscript>Al<Subscript>5</Subscript>O<Subscript>12</Subscript> crystal

Nd_0.03Lu_2.871Gd_0.099Al₅O₁₂ (Nd:LuGdAG) crystal was grown by the Czochralski method. The absorption, fluorescence spectra and fluorescence lifetime of Nd:LuGdAG crystal at room temperature were investigated for the first time. We reported the continuous-wave (CW) Nd:LuGdAG laser operation under diode pumping. Output power of 1.43 W at 1064 nm was achieved with a slope efficiency of 34.1%. All the results show that Nd:LuGdAG crystal is a promising laser material.     

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.     

Continuous-wave Nd:GdVO<Subscript>4</Subscript>/LBO laser at 541.5 nm under diode pumping into the emitting level

We report a green laser at 541.5 nm generation by intracavity frequency doubling of a continuous wave (cw) laser operation of a 1083 nm Nd:GdVO₄ laser under 880 nm diode pumping into the emitting level ⁴ F _3/2. A LiB₃O₅ (LBO) 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 2.52 W of cw output power at 541.5 nm is achieved. The optical-to-optical conversion efficiency is up to 14.2%, and the fluctuation of the green output power was better than 3.6% in the given 30 min.     

Passively Q-switched laser performance of a diode-pump mixed Nd:Lu<Subscript>0.15</Subscript>Y<Subscript>0.85</Subscript>VO<Subscript>4</Subscript> crystal

A diode-pumped passively Q-switched Nd:Lu_0.15Y_0.85VO₄ laser with a GaAs output coupler is demonstrated. By using a mixed crystal Nd:Lu_0.15Y_0.85VO₄ as laser medium, the passively Q-switched laser can generate shorter pulse width with higher peak power in comparison with the passively Q-switched Nd:LuVO₄ or Nd:YVO₄ lasers under the same laser cavity. At the incident pump power 11.9 W, the minimum pulse width of 3.23 ns and the maximum peak power 1.67 kW can be obtained. The average output power and the pulse repetition rate of the laser are also measured. The experimental results show that the mixed crystal is a promising laser medium for shorter Q-switched pulse with higher peak power.     

Efficient blue emission of ytterbium-doped Sr<Subscript>5</Subscript>(PO<Subscript>4</Subscript>)<Subscript>3</Subscript>F under quasi-three-level intracavity pumping

We report an Yb:Sr₅(PO₄)₃F (Yb:S-FAP) laser emitting at 985 nm intracavity pumped by a 912 nm diode-pumped Nd:GdVO₄ laser. A 808 nm diode laser is used to pump the Nd:GdVO₄ crystal emitting at 912 nm, and the Yb:S-FAP laser emitting at 985 nm intracavity pumped at 912 nm. With incident pump power of 17.5 W, intracavity second harmonic generation has been demonstrated with a power of 131 mW at 492.5 nm by using a LBO nonlinear crystal.     

Efficient intracavity frequency-doubled Nd:YLiF<Subscript>4</Subscript>-LiB<Subscript>3</Subscript>O<Subscript>6</Subscript> red laser emission under diode pumping into the emitting level

We report for the first time (to our knowledge) an efficient compact red laser at 660.5 nm generation by intracavity frequency doubling of a continuous wave laser operation of a diode direct pumped Nd:YLiF₄ (Nd:YLF) laser on the ⁴ F _3/2 → ⁴ I _13/2 transition at 1321 nm. A LiB₃O₆ (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 16.2 W, as high as 1.5 W of continuous wave output power at 660.5 nm is achieved with 10-mm-long LBO. The optical-to-optical conversion efficiency is up to 9.3%. Comparative results obtained for the pump with diode laser at 806 nm, into the highly-absorbing ⁴ F _5/2 level, are given in order to prove the advantages of the 880 nm wavelength pumping.     

Experimental study on doubly QML Nd:Lu<Subscript>0.15</Subscript>Y<Subscript>0.85</Subscript>VO<Subscript>4</Subscript> laser with AO modulator and central SESAM

By using double-mixed crystal Nd:Lu_0.15Y_0.85VO₄ as laser medium, a diode-pumped doubly Q-switched and mode-locked (QML) Nd:Lu_0.15Y_0.85VO₄ laser with acousto-optic (AO) modulator and central semiconductor saturable absorption mirror (SESAM) is realized for the first time. The Q-switched envelope modulation depth is nearly 100%.The average output power and the pulse width of the Q-switched envelope etc. for different AO modulator repetition rates have been measured. The experimental result show that Nd:Lu_0.15Y_0.85VO₄ crystal is an excellent laser medium for doubly QML lasers.     

Efficient and compact intracavity-frequency-doubled Nd:LuVO<Subscript>4</Subscript>/LBO laser at 538 nm end-pumped by a fiber-coupled laser diode

We report a diode-pumped Nd:LuVO₄ laser emitting at 1076 nm, based on the ⁴ F _3/2−⁴ I _11/2 transition, generally used for a 1066 nm emission. A power of 689 mW at 1076 nm has been achieved in continuous-wave (CW) operation with a fiber-coupled laser diode emitting 17.8 W at 809 nm. Intracavity second-harmonic generation (SHG) in CW mode has also been demonstrated with a power of 105 mW at 538 nm by using a LiB₃O₅ (LBO) nonlinear crystal.     

Diode-pumped Yb:Y<Subscript>2</Subscript>SiO<Subscript>5</Subscript>-LiB<Subscript>3</Subscript>O<Subscript>5</Subscript> cyan laser at 501.7 nm

We describe the output performances of the 928 nm ⁴ F _3/2 → ⁴ I _9/2 transition in Nd:CLNGG under diode-laser pumping. An end-pumped Nd:CLNGG crystal yielded 1.3 W of continuous-wave output power for 17.8 W of absorbed pump power. The slope efficiency with respect to the absorbed pump power was 11.2%. Furthermore, with 17.8 W of diode pump power and the frequency-doubling crystal LiB₃O₅ (LBO), a maximum output power of 260 mW in the blue spectral range at 464 nm has been achieved. The blue output power stability over 4 h is better than 3.2%.     

Diode-pumped continuous-wave Nd<Superscript>3+</Superscript>:YAlO<Subscript>3</Subscript> intracavity-doubled red laser

It is reported that efficient continuous-wave (CW) red laser generation at 670 nm in a LBO crystal at type-I phase matching direction performed with a diode-pumped Nd³⁺:YAlO₃ (Nd:YAP) laser. With incident pump power of 15.6 W, output power of 273 mW at 670 nm has been obtained using a 10 mm-long LBO crystal. At the output power level of 273 mW, the output stability is better than 3.7%.     

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.     

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%.     

Quasi-three level laser based on diode-pumped Nd<Superscript>3+</Superscript>:YAlO<Subscript>3</Subscript> crystal

We describe the output performances of the 930 nm ⁴ F _3/2 → ⁴ I _9/2 transition in Nd³⁺:YAlO₃ (Nd:YAP) under in-band pumping with diode laser at the 803 nm wavelength. An end-pumped Nd:YAP crystal yielded 1.13 W of continuous-wave (CW) output power for 17.8 W of incident pump power. Moreover, intracavity second-harmonic generation has also been achieved with a power of 172 mW at 465 nm by using a LiB₃O₅ (LBO) nonlinear crystal. The blue beam quality factor M ² was less than 1.3. The blue power stability was less 3% in 60 min.     

Completely solid-state LD-side-pumped Nd:YAlO<Subscript>3</Subscript> CW blue laser with intracavity frequency tripling

We report a completely solid-state continuous-wave (CW) blue laser operating at 447 nm utilizing intracavity frequency tripling of an LD-side-pumped Nd:YAlO₃ (Nd:YAP) laser operating at 1341.4 nm. An LBO crystal with type-I critical phase matching and a KTP crystal with type-II critical phase matching (CTM) were used for the second harmonic generation (SHG) and the third harmonic generation (THG), respectively. In view of the analysis of the cavity stability, a four-mirror folded cavity was designed and the output characteristics were theoretically analyzed. Experimental characteristics obtained were shown to be in agreement with the theoretical analysis. The maximum output power of the 447 nm CW blue laser reached 114 mW, which corresponds to a red-to-blue conversion efficiency of 9%.     

All-solid-state continuous-wave frequency-doubling Nd:LuVO<Subscript>4</Subscript>/GBCOB laser at 533 nm

We report an efficient intracavity second-harmonic generation (SHG) at 1066 nm in a non-linear optical crystal, GdCa₄O(BO₃)₃ (GdCOB), performed with a diode end pumped continuous-wave (CW) Nd:LuVO₄ laser. In the case of a laser with a Nd:LuVO₄ crystal frequency-doubled with a GdCOB crystal cut for type I frequency doubling. A CW SHG output power of 5.18 W has been obtained using a 10 mm long GCOB crystal. The optical conversion efficiency with respect to the incident pump power was 28.5%.     

Diode-pumped passively Q-switched and mode-locked Nd:Lu<Subscript>0.15</Subscript>Y<Subscript>0.85</Subscript>VO<Subscript>4</Subscript> laser with a GaAs saturable absorber

By using a-cut Nd:Lu_0.15Y_0.85VO₄ mixed crystal as laser gain medium, a diode-pumped passively Q-switched and mode-locked (QML) laser with a GaAs saturable absorber in a Z-type folded cavity is demonstrated for the first time. The Q-switched mode-locked laser pulses with about 90% modulation depth are obtained as long as the pump power reached the oscillation threshold. The repetition rate of the passively Q-switched pulse envelope ranges from 50 to 186 kHz as the pump power increases from 0.915 to 6.520 W. Under an incident pump power of 6.52 W, the QML pulses with the largest average output power of 694 mW, the shortest pulse width of 200 ns and the highest pulse energy of 3.73 μJ are obtained. The mode-locked pulse width inside the Q-switched envelope is estimated to be about 275 ps. The experimental results show that Nd:Lu_0.15Y_0.85VO₄ is a promising mixed crystal for QML laser.     

Efficient continuouswave laser at 560 nm by intracavity frequency summation of fundamental and first-stokes wavelengths in a Nd:YVO<Subscript>4</Subscript>-BaWO<Subscript>4</Subscript> Raman laser

We report for the first time an efficient CW laser emission at 560 nm by sum-frequency mixing of the fundamental and first-Stokes fields generated within an Nd:YVO₄-BaWO₄ Raman laser. Intracavity sumfrequency mixing with LiB₃O₅ (LBO) nonlinear crystal yielded 1.12 W of visible yellow-green emission; the output power stability over 4 h is better than 3.3%. The laser beam quality M ² factors are 1.84 and 2.43 in both horizontal and vertical dimensions respectively.