Diode-pumped Q-switched Extra-cavity Frequency-dou bled Nd∶YVO_4/KTP Green Laser

A diode-pumped acousto-op ti cal(A-O) Q-switched extra-cavity frequency-doubled Nd∶YVO_ 4/ KTP (KTiO PO_ 4) green laser formed with a simple plane-plane cavity has been demonst rated. With the incident pump power of 12.7 W, A-O Q-switched average output power at 1 064 nm was 3.81 W with a duration of 25 ns at a repetition rate of 20 kHz, extra-cavity frequency doubling with KTP as the nonlinear crystal y ielded the maximum output power of 1.92 W at 532 nm, the corresponding optical conversion efficiency from 1 064 nm to 532 nm light is 50.4%. The continuous -wave(CW) laser properties of diode-pumped Nd∶YVO_ 4 crystal operating at 1 064 nm have been studied. With the incident pump power of 25 W, the maximu m CW output power of 13.81 W was obtained with the corresponding optical conver sion efficiency of 55.24%.     

Laser-diode pumped Nd: GdVO4 ultraviolet laser with LBO frequency tripling

We have demonstrated a laser-diode pumped Nd.GdVO4 extra-cavity frequency tripling ultraviolet laser with a LBO crystal in this paper. Under the acousto-optic （A-O） Q-switched operation, we have obtained 355 nm ultraviolet laser,with pulse width of 25 ns and pulse repetition rate of 20 kHz. By using a type Ⅰ non-critical phase-matched LBO crystal, the SHG output power of 822 mW is achieved at the incident pump power of 16 W. The output power of 355nm UV laser is 260mW with a type Ⅱ phase-matched LBO crystal,and the conversion efficiency （1 064 nm-355 nm） is 5.9 %. The power stability of 355 nm laser is 1.7% in 1 h.     

Efficient Mode-locked and Q-switched Nd∶YVO4 Laser with Semiconductor Saturable Absorber Mirror

We reported an efficient diode pumped Nd∶YVO4 1 064 nm laser passively mode-locked and Q-switched by a semiconductor saturable absorber mirror(SESAM). At the incident pump power of 7.5 W, 2.81 W average output power was obtained during stable CW mode locking with a repetition rate of 111 MHz. The optical conversion efficiency was 37.5%, and the slope efficiency was 39%. So far as we know, this is the highest optical-optical conversion efficiency with a SESAM at home.     

Analysis and design of CW-LD pumped stable Q-switched laser

A high power continuous wave (CW) laser diode (LD) pumped acousto-optic Q-switched Nd:YVO4 laser is presented. A short pulse at the 1064 nm is obtained. With a repetition rate of 50 kHz, the maximum average output power of 5.72 W is achieved. The optical conversion efficiency and the slope efficiency are up to 28% and 32.4% respectively. At the repetition rate of 10 kHz and the pulse width of 16.3ns, the maximum single pulse energy of 286 μJ and the peak power of 13kW are acquired. The laser can be used as a signal source in the free-space optical communication. The output signal agrees with the modulate signal well.     

Diode-end-pumped Nd：YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave(CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd:YVO4 and using LBO as the intra-cavity SHG crystal.With the optimization of laser cavity and crystal parameters,the laser operates at a very high efficiency.When the pumping power is about 31 W,the output at 457 nm reaches 4.2 W,and the optical to optical conversion efficiency is about 13.5% accordingly.The stability of the output power is better than 1.2% for 8 h continuously working.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave （CW） 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd： YVO4 and using LBO as the intra-cavity SHG crystal. With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457 nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the output power is better than 1.2% for 8 h continuously working.     

Efficient Mode-locked and Q-switched Nd ： YVO4 Laser with Semiconductor Saturable Absorber Mirror

We reported an efficient diode pumped Nd ： YVO4 1 064 nm laser passively mode-locked and Qswitched by a semiconductor saturable absorber mirror（SESAM）. At the incident pump power of 7. 5 W, 2.81 W average output power was obtained during stable CW mode locking with a repetition rate of 111 MHz. The optical conversion efficiency was 37.5%, and the slope efficiency was 39%. So far as we know, this is the highest optical-optical conversion efficiency with a SESAM at home.     

A 3.63 W Nd：YVO4 orange-yellow laser with intracavity sum-frequency mixing

A design of laser-diode array (LDA) end-pumped Nd:YVO4 laser that generates simultaneously wavelengths of 1064 nm and 1342 nm is presented, and by using type-I critical phase matching (CPM) of BiB3O6, 593.5 nm continuous-wave (CW) laser is obtained with intracavity sum-frequency mixing. The maximum laser output power can reach 3.63 W with the pump power of 27.5 W. The optical-to-optical conversion efficiency is up to 13.2%, which is the highest value at 593.5 nm by the intracavity sum-frequency ...     

Diode-pumped actively Q-switched Nd： YAG laser at 946 nm

A diode-pumped Nd： YAG acousto-optically（A-O） Q-switched laser at wavelength 946 nm formed with a simple plane-plane cavity has been demonstrated. The maximum average output power was 850 mW. The highest peak power was 531 W with the pulse repetition rate of 20 kHz and pulse width of 80 ns at the incident pump power of 19.5 W.     

A low-threshold efficient KTA OPO by a fiber-coupled diode-end-pumped Nd:YVO4 laser

A low-threshold efficient high-repetition-rate eye-safe optical parametric oscillator(OPO) is presented.The OPO is based on an x-cut non-critically phase-matched(NCPM) KTA intra-cavity pumped by an acousto-optically(A-O) Q-switched Nd:YVO4 laser.At 10 kHz,the lowest threshold of 0.75 W and the signal power of 0.6 W are got,corresponding to the single pulse energy of 60 μJ and the peak power of 20 kW.Tuning the frequency,the maximum output power at 1536 nm is 1.03 W at 30 kHz with an optical-to-optical conve...     

Compact yellow-orange Nd:YVO4/PPMgLN laser at 589 nm

We propose and make a compact yellow-orange laser of the Nd-doped yttrium vanadate (Nd:YVO4)/periodically poled Mg-doped lithium niobate (PPMgLN) module by Raman frequency-doubling at 589 nm. By reasonably designing the size of the Nd:YVO4 and 5 mol% PPMgLN crystals, cavity length and coating parameter, a compact 589 nm laser module with a total size of 3 mm×10 mm×1.5 mm is fabricated. In the laser module, the input surface of Nd:YVO4 crystal is end-pumped by an 808 nm laser diode (LD). Under the effect of linear resonant cavity structure, the output surface of PPMgLN crystal with a period of 9.48 μm generates 589 nm yellow-orange light. The experimental results show that the maximum output power at 589 nm is 390 mW at the pump power of 3 W with the optical-optical conversion efficiency of 13% and the stability of the output power is less than 2% within 3 h.     

A compact dual-band bandpass filter based on porous silicon dual-microcavity of one-dimensional photonic crystal

We demonstrate a laser-diode(LD)pumped actively Q-switched laser with Nd:Sc0.2Y0.8Si O5(Nd:SYSO)crystal for the first time.A stable actively Q-switched laser is obtained at dual wavelengths of 1 075.2 nm and 1 078.2 nm.The maximum average output power of 720 m W is obtained at the repetition rate of 15 k Hz under the pump power of8.7 W.The minimum pulse width of 58 ns is obtained at the repetition rate of 5 k Hz under the pump power of 8.7 W,corresponding to the peak power of 1.9 k W and the pulse energy of 112μJ.     

Study on the Pr:KYF ultraviolet laser at 305 nm pumped by blue laser

An all-solid-state Pr:KY3F10(Pr:KYF) laser pumped by blue laser(471 nm) has been demonstrated.With the incident pump power of 2.6 W,the maximum output power at 610 nm is 213 mW.Moreover,the intracavity second-harmonic generation(SHG) is also achieved with the maximum ultraviolet(UV) power at 305 nm of 11 mW by using a β-BaB2O4(BBO) nonlinear crystal.     

High power output quasi-continuous-wave nanosecond optical parametric generator based on periodically poled lithium niobate

We report on a high power output quasi-continuous-wave nanosecond optical parametric generator （OPG） of congruent periodically poled lithium niobate （PPLN） pumped by a 1 064 nm acousto-optically Q-switched Nd-YVO4 laser （duration. 70 ns,repetition rate：45 kHz,spatial beam quality M2〈 1,3）. The OPG consists of a 38.7 mm long PPLN crystal with a domain period of 28.93 μm. With 5.43 W of average pump power the maximum average output power is 991 mW at 1 517.1 nm signal wave of the PPLN OPG.     

Q-switched and Mode-locked Characteristics of Cr~(4+)∶YAG Crystal

The passively Q-switched and mode-locked(QML) characteristics in a diode-pumped Nd∶GdVO_4 laser with Cr~(4+)∶YAG saturable absorbers have been demonstrated. A maximum average output power of 710mW has been obtained in the QML laser. The maximum energy of a single Q-switched pulse is 52.5μJ, with the corresponding pulse width of 30ns and the peak power of 1.75kW, at the incident pump power of 7.75W. The repetition rates of the Q-switched envelope and the mode-locked laser pulse are 16.7kHz and 680MHz, respectively.     

Q-switched and Mode-locked Characteristics of Cr^4＋： YAG Crystal

The passively Q-switched and mode-locked （QML） characteristics in a diode-pumped Nd： GdVO4 laser with Cr^4＋： YAG saturable absorbers have been demonstrated. A maximum average output power of 710 mW has been obtained in the QML laser. The maximum energy of a single Q-switched pulse is 52.5μJ, with the corresponding pulse width of 30 ns and the peak power of 1.75 kW, at the incident pump power of 7. 75 W. The repetition rates of the Q-switched envelope and the mode-locked laser pulse are 16.7 kHz and 680 MHz, respectively.     

C-cut Nd-doped vanadate crystal self-Raman laser with narrow Q-switched envelope and high mode-locked repetition rate

In this paper, a passively Q-switched and mode-locked c-cut Nd-doped vanadate crystal self-Raman laser at 1.17 μm is firstly demonstrated by using Cr^4＋：YAG. Two crystals of Nd^3＋：YVO4 and Nd^3＋：Gd VO4 are adopted to generate laser, respectively. With the incident pump power of 13 W, the average output powers of 678 m W and 852 m W at 1.17 μm are obtained with the durations of Q-switched envelope of 1.8 ns and 2 ns, respectively. The mode-locked repetition rates are as high as 2.3 Hz and 2.2 GHz, respectively. As far as we know, the Q-switched envelope is the narrowest and the mode-locked repetition rate is the highest at present in this field. In addition, yellow laser output is also achieved by using the Li B3O5 frequency doubling crystal.     

Passive mode locked diode-pumped Nd：GdYVO4 laser with a GaAs absorber

A passively Q-switched mode-locked Nd:GdYVO4 laser is successfully demonstrated by using a piece of GaAs crystal grown at low temperature as the passively saturated absorber and the output coupler. Fundamental properties of the Nd: GdYVO4 laser are investigated. The maximum average output power of 3.5 W is obtained by using plainsphere when the incident pumping power is 10 W,which corresponds to an optical-optical coversion efficiency of 35%. The threshold power for the Q-switching mode-locked is 1.2 W. The maximum average output power of 1.72 W is obtained by using GaAs when the incident pumping power is 10 W,mode-locked pulse train with a repetition rate of ～113 MHz is achieved. At the incident laser pumping power of 7 W,the modulation depth is 100%.     

LD side-pumped intracavity frequency-doubled high Nd：YAG green laser based on acousto-optic Q-switch

A highly efficient and high power green laser generated by intracavity frequency doubling of a diode-sidepumped Q-switched Nd：YAG laser has been demonstrated. In the simple L-shaped cavity geometry,the maximum green output power of 28.5 W was obtained with a pulse width of 95 ns at a pulse repetition rate of 10 kHz by using a LBO crystal for frequency doubling,corresponding to a conversion efficiency of 11% from diode pump power to pulse green power. At a pulse repetition rate of 1 kHz,6.9 mJ of pulse energy,25 ns of pulse duration and 276 kW of peak power were obtained.     

Fabrication of narrow pulse passively Q-switched self- stimulated Raman laser with c-cut Nd:GdVO4

Combining the self-stimulated Raman scattering technology and saturable absorber of Cr4+:YAG, a 1.17 μm c-cut Nd:GdVO4 picosecond Q-switched laser is demonstrated in this paper. With an incident pump power of 10 W, the Q-switched laser with average power of 430 mW for 1.17 μm, pulse width of 270 ps, repetition rate of 13 kHz and the first order Stokes conversion efficiency of 4.3% is obtained. The Q-switched pulse width can be the narrowest in our research. In addition, the yellow laser at 0.58 μm is also achieved by using the LiB3O5 frequency doubling crystal.