Cascaded third-harmonic generation with one KDP crystal.

For KH2PO4 (KDP) crystal, the phase-matching directions of type-II second-harmonic generation (SHG) and type-II third-harmonic generation (THG) for 1 μm lasers are almost identical, i.e., at (θ=60°, φ=0°) around. Utilizing this special property, we designed a THG converter based on one KDP crystal. A quarter-wave (λ/4) plate was used to adjust the polarization of the SHG wave, and a round-trip optical path was used to realize the SHG and THG procedures successively. When the fundamental light source was a 1064 nm, 40 ps pulse laser, the maximum THG output at 355 nm was 1.13 mJ, and the highest THG conversion efficiency was 30.7%. To the best of our knowledge, this is the first time that the cascaded frequency upconversion processes are realized in one bulk nonlinear optical crystal. This method possesses many advantages for future applications, including high efficiency, a wide-working waveband, low cost, and applicability to many other crystals such as DKDP, ADP, DADP, and GdxY1-xCOB.

[1]  F. Seifert,et al.  Extension of the tuning range of a femtosecond Ti:sapphire laser amplifier through cascaded second‐order nonlinear frequency conversion processes , 1994 .

[2]  D. Neely,et al.  Surface transport of energetic electrons in intense picosecond laser-foil interactions , 2011 .

[3]  V. V. Slabko,et al.  Random quasi-phase-matched nonlinear optical conversion of supercontinuum to the ultraviolet , 2013 .

[4]  R. S. Craxton,et al.  High efficiency frequency tripling schemes for high-power Nd: Glass lasers , 1981 .

[5]  Tao Wang,et al.  Optimization of quadrature frequency conversion with type-II KDP for second harmonic generation of the nanosecond chirp pulse at 1053 nm , 2014 .

[6]  Wei Wang,et al.  Comparison of efficient third-harmonic generation between phase modulated broadband and narrowband lasers , 2011 .

[7]  M. Tsuchiya,et al.  Highly Efficient Third Harmonic Generation in a Periodically Poled MgO:LiNbO3 Disk Resonator , 2009 .

[8]  V. Petrov,et al.  High-efficiency single-crystal third-harmonic generation in BiB₃O₆. , 2011, Optics letters.

[9]  Nai-Ben Ming,et al.  Simultaneously efficient blue and red light generations in a periodically poled LiTaO3 , 2001 .

[10]  J. Ma,et al.  Second - harmonic generation of ultra-high intensity femtosecond pulses with a KDP crystal. , 2001, Optics express.

[11]  A. Lagendijk,et al.  Simultaneous phase matching of three second-order nonlinear optical processes in LiNbO3 , 1989 .

[12]  M. Levenson,et al.  Continuous-wave frequency tripling and quadrupling by simultaneous three-wave mixings in periodically poled crystals: application to a two-step 1.19-10.71-microm frequency bridge. , 1997, Optics letters.

[13]  Hui-Tian Wang,et al.  Ultraviolet generation in a dual-periodic domain inverted structure in LiTaO3 crystal by frequency tripling a 1.064 μm laser , 2001 .

[14]  Theodor W. Hänsch,et al.  ALL SOLID STATE LASER SOURCE FOR TUNABLE BLUE AND ULTRAVIOLET RADIATION , 1995 .

[15]  J. L. He,et al.  Quasi-Cw Ultraviolet Generation in a Dual-periodic LiTaO3Superlattice by Frequency Tripling , 2001 .

[16]  F. Zernike,et al.  Refractive Indices of Ammonium Dihydrogen Phosphate and Potassium Dihydrogen Phosphate between 2000 A and 1.5 mu: Errata , 1965 .

[17]  J K Lawson,et al.  Harmonic conversion of large-aperture 1.05-microm laser beams for inertial-confinement fusion research. , 1992, Applied optics.

[18]  Andrzej Majchrowski,et al.  Efficient third harmonic generation of microjoule picosecond pulses at 355nm in BiB3O6 , 2006 .

[19]  R. Srinivasan.  Photokinetic etching of polymethyl methacrylate films by continuous wave ultraviolet laser radiation , 1991 .

[20]  Nai-Ben Ming,et al.  Quasi-phase-matched third-harmonic generation in a quasi-periodic optical superlattice , 1997 .

[21]  Xinping Zhang,et al.  Simultaneously phase-matched parametric processes in a single-pass interaction for efficient visible generation , 2010 .

[22]  Dyson,et al.  Efficient extreme UV harmonics generated from picosecond laser pulse interactions with solid targets. , 1996, Physical review letters.

[23]  Benxin Wu,et al.  Physical mechanisms for picosecond laser ablation of silicon carbide at infrared and ultraviolet wavelengths , 2010 .