Intracavity Sum-frequency Generation Research Articles

Tunable, continuous-wave optical parametric oscillator with more than 1W output power in the orange visible spectrum.

We report on the implementation of an all-solid-state optical parametric oscillator (OPO) laser system, pumped by a fiber laser, and extended by intra-cavity sum frequency generation (SFG) to provide tunable radiation with output powers well beyond 1 W in the visible regime between 605 and 616 nm. We use periodically poled sections for quasi phase-matched OPO and SFG processes, implemented on a single MgO:PPLN crystal. A Pound-Drever-Hall frequency stabilization reduces the laser linewidth to the range of 100 kHz (FWHM), determined by measurements of spectral hole burning in a rare-earth ion doped crystal as well as analysis of side-of-fringe transmission in a low finesse Fabry-Perot resonator.

All-solid-state side-pumped intracavity sum frequency generation yellow laser at 589 nm with the output power of 11.4 W

A laser diode side pump all-solid-state pulse laser at 589 nm with high power and high conversion efficiency and small volume is demonstrated by intracavity sum frequency generation. By optimizing the cavity and adopting etalon techniques, a quasi continuous wave at 589 nm laser source, which has a maximum output power of 11.4 W, a repetition rate of 5 kHz, and a pulse width of 135 ns, is developed. The optical to optical conversion efficiency is up to 6.5% and the power stability is better than 2% in 8 hours.

Efficient yellow beam generation by intracavity sum frequency mixing in DPSS Nd:YVO4 laser

We present our studies on dual wavelength operation using a single Nd:YVO4 crystal and its intracavity sum frequency generation by considering the influence of the thermal lensing effect on the performance of the laser. A KTP crystal cut for type-II phase matching was used for intracavity sum frequency generation in the cavity at an appropriate location for efficient and stable yellow output power. More than 550 mW of stable CW yellow-orange beam at 593.5 nm with beam quality parameter (M2) ∼4. 3 was obtained. The total pump to yellow beam conversion efficiency was estimated to be 3.83%.

High power red to mid-infrared laser source from intracavity sum frequency optical parametric oscillator pumped by femtosecond fiber laser

A femtosecond laser source tuned from red to mid-infrared is demonstrated. It is based on intracavity sum frequency generation of a MgO-doped periodically poled LiNbO3 optical parametric oscillator synchronously pumped by mode-locked Yb large-mode-area photonic crystal fiber, which has high average power and high repetition rate. The optical parametric oscillator has a wide spectral tuning range from 1450–2200 nm (for the signal) and 2250–4000 nm (for the idler) while the wavelength of the pump is 1040 nm. In the experiment, the output power of 374 mW at 1502 nm is achieved when the pump power is 2 W and the slope efficiency is 18.7%. In addition, 166 mW idler at 3.4 μm are achieved. By using a β-BaB2O4 for intracavity sum frequency generation, the femtosecond pulse over 610–668 nm is obtained. A 694 mW average output power of sum frequency generation is achieved for 4.1 W pump, representing 16.9% conversion efficiency at 615 nm.

All-Solid-State Side-Pumped Intracavity Sum Frequency Generation Yellow Laser at 589 nm with the Output Power of 11.4 W

All-Solid-State Side-Pumped Intracavity Sum Frequency Generation Yellow Laser at 589 nm with the Output Power of 11.4 W

An efficient all-solid-state doubly resonant continuous-wave ultraviolet laser at 284 nm

We report for the first time coherent ultraviolet radiation at 284 nm by intracavity sum-frequency generation of a 607 nm Pr:YLF laser and a 532 nm frequency doubling Nd:YVO4 laser. The ultraviolet laser is obtained by using double resonator, type-I critical phase matching CsLiB6O10 (CLBO) crystal sum-frequency mixing. With a total pump power of 18.8 W (3.1 W pump power for the 607 nm Pr:YLF laser and 15.7 W pump power for the 532 nm Nd:YVO4 frequency doubling laser), a TEM00 mode ultraviolet laser beam at 284 nm of 242 mW is obtained. The power stability is better than 3.4% and laser beam quality M2 factors are 1.13 and 1.22 in the horizontal and vertical dimensions respectively.

Tunable, continuous-wave, ultraviolet source based on intracavity sum-frequency-generation in an optical parametric oscillator using BiB_3O_6

We report a continuous-wave (cw) source of tunable radiation across 333-345 nm in the ultraviolet (UV) using bismuth triborate, BiB₃O₆ (BIBO) as the nonlinear gain material. The source is based on internal sum-frequency-generation (SFG) in a cw singly-resonant optical parametric oscillator (OPO) pumped at 532 nm. The compact tunable source employs a 30-mm-long MgO:sPPLT crystal as the OPO gain medium and a 5-mm-long BIBO crystal for intracavity SFG of the signal and pump, providing up to 21.6 mW of UV power at 339.7 nm, with >15 mW over 64% of the SFG tuning range. The cw OPO is also tunable across 1158-1312 nm in the idler, delivering as much as 1.7 W at 1247 nm, with >1W over 65% of the tuning range. The UV output at maximum power exhibits passive power stability better than 3.4% rms and frequency stability of 193 GHz over more than one minute.

An efficient all-solid-state doubly resonant sum-frequency continuous-wave ultraviolet laser at 299 nm

We report for the first time coherent ultraviolet radiation at 299 nm by intracavity sum-frequency generation of an 899 nm Nd:YAG laser and a 456 nm frequency doubling Nd:GdVO4 laser. The ultraviolet laser is obtained by using doubly resonant, type-I critical phase matching CsLiB6O10 (CLBO) crystal sum-frequency mixing. With a total diode pump power of 35.6 W (17.2 W pump power for the 899 nm Nd:YAG laser and 18.4 W pump power for the 456 nm Nd:GdVO4 frequency doubling laser), a TEM00 mode ultraviolet laser at 299 nm of 331 mW is obtained. The power stability is better than 3.4% and the laser beam quality M2 factors are 1.22 and 1.17 in the horizontal and vertical dimensions respectively.

Intracavity sum-frequency diode side-pumped all-solid-state generation yellow laser at 589 nm with an output power of 205 W

A laser diode side-pumped all-solid-state pulse laser at 589 nm with high power, high conversion efficiency, and a small volume is demonstrated by intracavity sum-frequency generation. By carefully optimizing the cavity and adopting various techniques, a quasi-cw free oscillation yellow laser source, which has a maximum output power of 20.5 W, a repetition rate of 14.49 KHz, and a pulse width of 157 ns, is developed. The optical-to-optical conversion efficiency is up to 5.11%, and the power stability is better than 2% in 2 h.

Tunable type II intracavity sum-frequency generation in a two chip collinear vertical external cavity surface emitting laser

We report on the generation and experimental demonstration of intracavity type II sum-frequency generation (SFG) in a two chip InGaAs/GaAs vertical external cavity surface emitting laser cavity. The demonstrated two-chip cavity generates two orthogonally polarized, independently tunable, high-intensity intracavity lasing modes at different colors. Using a lithium triborate nonlinear crystal in the common collinear folded cavity region, high output power in the blue-green band is generated. Wavelength tuning with CW output powers in excess of 750 mW is demonstrated. By independent wavelength tuning of each fundamental color, tunable SFG output around 490 nm is reported.

High power Q-switched intracavity sum-frequency generation and self-Raman laser at 559 nm

We report a diode-end-pumped acousto–optically Q-switched composite YVO4/Nd:YVO4/YVO4 crystal self-Raman yellow–green laser, based on the intracavity sum-frequency generation of the fundamental and first-Stokes fields in LiB3O5 crystal. Maximum average output power at 559nm is 3.55W at the incident pump power of 32W and pulse repetition frequency (PRF) of 30kHz, with an optical conversion efficiency of 11%. The highest pulse energy and peak power are 129μJ and 10.5kW at 20kHz PRF, respectively. The power stability of yellow–green radiation is better than 2% for 40min at an average output power around 3W.

Cascaded self-Raman lasers based on 382 cm^−1 shift in Nd:GdVO_4

We report quasi-continuous-wave, cascaded Nd:GdVO(4) self-Raman lasers based on a secondary Raman transition at 382 cm(-1) for which the Raman gain was estimated to be 0.7 cm/GW. Laser output was obtained in the near-infrared at 1108 nm, 1156 nm and 1227 nm. By incorporating intracavity sum-frequency generation (SFG) or second-harmonic generation (SHG), high power output at four discrete visible wavelengths could be selected, specifically 3.4 W at 542 nm, 2.8 W at 554 nm, 1.4 W at 566 nm and 0.8 W at 577 nm, with corresponding diode-to-visible optical conversion efficiencies of 11.7%, 9.7%, 4.8% and 2.7% respectively.

Diode-pumped green light source based on intracavity sum frequency generation

We report a continuous-wave (CW) green laser emission by sum-frequency mixing in Nd:YVO4 and Nd:YLF crystals. Using type-II critical phase-matching (CPM) KTP crystal, a green laser at 539 nm is obtained by 914 and 1313 nm intracavity sum-frequency mixing. The maximum laser output power of 388 mW is obtained when an incident pump laser of 18.2 W is used. At the output power level of 388 mW, the output stability is better than 4.6%.

494 nm blue laser based on sum-frequency mixing of diode pumped Nd3+ lasers

We report for the first time a continuous-wave (CW) blue radiation at 494 nm by intracavity sumfrequency generation of 912 nm Nd:GdVO4 laser and 1079 nm Nd:YAlO3 (Nd:YAP) laser. Using type-I critical phase matching LiB3O5 (LBO) crystal, 494 nm blue laser was obtained by 912 and 1079 nm intra-cavity sum-frequency mixing, and output power of 179 mW was demonstrated. At the output power level of 179 mW, the output power stability is better than 3.5% and laser beam quality M 2 factor is 1.21.

LD end-pumped c-Cut Nd:YVO4/KTP self-Raman laser at 560 nm

Intra-cavity sum frequency generation (SFG) of c-cut Nd:YVO4 self-Raman laser was investigated for the first time. A 4 × 4 × 10 mm3 KTP crystal with a type-II phase-matching cutting angle (θ = 83.4°, φ = 0°) was used for SFG between the fundamental light at 1066 nm and first-Stokes light at 1178 nm. The laser system with different curvature radii of output couplers and different pulse repetition frequencies were investigated. At a pump power of 14 W and pulse repetition frequency of 20 kHz, the average output power of yellow-green laser at 560 nm up to 840 mW was achieved, corresponding to a slope efficiency of 7.6% and a conversion efficiency of 6% with respect to diode pump power.

A continuous-wave tunable orange-red source based on sum-frequency generation in an intra-cavity periodicallypoled LiNbO3 singly resonant optical parametric oscillator cavity

This work demonstrates a tunable continuous-wave (CW) all-solid-stateorange-red source based on sum-frequency generation (SFG), using a tunable 1.4–1.5 µm signal and a 1064 nm pump of an intra-cavity periodically poledLiNbO3 optical parametricoscillator in a BBO (β-BaB2O4) crystal. Elaborate intra-cavity design ensured efficient CW singly resonant opticalparametric oscillator (SRO) operation. Intra-cavity SFG made full use of the highcirculating pump and signal power of the SRO under an external laser diode (LD) pumppower that was ten times higher than the SRO threshold. The output wavelength tuningrange was 605–623 nm. The maximum output power was 370 mW at 622.8 nmwith 17.1 W LD pump power, corresponding to an overall conversion efficiency of2.2%.

Compact 498-nm light source based on intracavity sum-frequency Nd:GGG laser

We report a coherent cyan radiation at 498 nm by intracavity sum-frequency generation of the 937 and 1062 nm laser-lines of the Nd:GGG crystal. With a diode pump power of 18.2 W, the maximum cyan output power of 186 mW is obtained. The beam quality M2 value is 1.22 in the horizontal plane. The output power stability over 30 min is better than 5%. To the best of our knowledge, this is first work on intracavity sum-frequency generation of a diode pumped Nd:GGG laser at 498 nm.

504 nm blue-green laser based on sum-frequency mixing of diode pumped Nd3+ lasers

We report for the first time a continuous-wave (CW) blue-green radiation at 504 nm by intracavity sum-frequency generation of 946 nm Nd:YAG laser and 1080 nm Nd:YAlO3 (Nd:YAP) laser. Using type-I critical phase matching LiB3O5 (LBO) crystal, 504 nm blue-green laser was obtained by 946 and 1080 nm intra-cavity sum-frequency mixing, and output power of 215 mW was demonstrated. At the output power level of 215 mW, the output power stability is better than 4.7% and laser beam quality M2 factor is 1.21.

Diode laser pumped green light source based on intracavity sum frequency generation

We report a continuous-wave (CW) green laser emission by sum-frequency mixing in Nd:YVO4 and Nd:YLF crystals. Using type-II critical phase-matching (CPM) KTP crystal, a green laser at 539 nm is obtained by 914 and 1313 nm intracavity sum-frequency mixing. The maximum laser output power of 388 mW is obtained when an incident pump laser of 18.2 W is used. At the output power level of 388 mW, the output stability is better than 4.6%.

480-nm blue laser based on sum-frequency mixing of diode pumped Nd:ASL-Yb:YAG lasers

We report for the first time a continuous-wave (CW) coherent radiation at 480 nm by intracavity sum-frequency generation of 900 nm Neodymium Doped Strontium and Lanthanum Aluminate (Nd:ASL) laser and 1030 nm Yb:Y3Al5O12 (Yb:YAG) laser. Blue laser is obtained by using a doubly cavity, type-I critical phase matching LiB3O5 (LBO) crystal sum-frequency mixing. With total pump power of 28.6 W, the blue laser at 480 nm of 170 mW is obtained. At the output power level of 170 mW, the blue power stability is better than 4.7% and laser beam quality M2 factor is 1.43.