517 nm - 538 nm tunable second harmonic generation in a diode-pumped PPKTP waveguide crystal

Tunable continuous wave (CW) green light generation between 517 nm and 538 nm at room-temperature has been demonstrated from a frequency-doubled broadly tunable quantum well (QW) external-cavity fiber-coupled diode laser by use of an uncoated periodically poled potassium titanyl phosphate (PPKTP) crystal aveguide crystal. Green light at 530 nm with maximum conversion efficiency of 14.8% and output power of 12.88 mW has been generated using a PPKTP crystal waveguide with the cross-sectional area of 3x5μm2. The possibility of tunable second harmonic generation in the PPKTP crystal waveguides with the cross-sectional areas of 4x4μm2 and 2x6μm2 was also investigated

Second harmonic generation in a low-loss orientation-patterned GaAs waveguide

The technology of low-loss orientation-patterned gallium arsenide (OP-GaAs) waveguided crystals was developed and realized by reduction of diffraction scattering on the waveguide pattern. The propagation losses in the OP-GaAs waveguide were estimated to be as low as 2.1 dB/cm, thus demonstrating the efficient second harmonic generation at 1621 nm under an external pumping

Quantum-dot saturable absorber and Kerr-lens mode-locked Yb:KGW laser with >450 kW of peak power

The hybrid action of quantum-dot saturable absorber and Kerr-lens mode locking in a diode-pumped Yb:KGW laser was demonstrated. Using a quantum-dot saturable absorber with a 0.7% (0.5%) modulation depth, the mode-locked laser delivered 90 fs (93 fs) pulses with 3.2 W (2.9 W) of average power at the repetition rate of 77 MHz, corresponding to 462 kW (406 kW) of peak power and 41 nJ (38 nJ) of pulse energy. To the best of our knowledge, this represents the highest average and peak powers generated to date from quantum-dot saturable absorber-based mode-locked lasers

Femtosecond Alexandrite Laser with InP/InGaP Quantum-Dot Saturable Absorber

A semiconductor saturable absorber mirror (SESAM) passively mode-locked Alexandrite laser was demonstrated. Using an InP/InGaP quantum-dot saturable absorber mirror, pulse duration of 380 fs at 775 nm was obtained. The laser was pumped at 532 nm and generated 295 mW of average output power in mode-locked regime with a pump power of 7.3 W. To the best of our knowledge, this is the first report of a passively mode-locked Alexandrite laser using SESAM in general and quantum-dot SESAM in particular

A novel type of quasi-phasematching for the second harmonic generation

We propose a novel type of quasi-phasematching for the second harmonic generation in periodically-poled nonlinear crystals. In contrast to the conventional quasiphasematching where one (or few) quasi-wavevector(s) of periodical poling compensate for the momentum mismatch between a pair of the fundamental photons and the SHG one, with the proposed mechanism the momentum mismatch between several pairs of fundamental and SHG photons is compensated with one quasi-wavevector of periodical poling

Femtosecond Alexandrite Laser with InP/InGaP Quantum-Dot Saturable Absorber

A semiconductor saturable absorber mirror (SESAM) passively mode-locked Alexandrite laser was demonstrated. Using an InP/InGaP quantum-dot saturable absorber mirror, pulse duration of 380 fs at 775 nm was obtained. The laser was pumped at 532 nm and generated 295 mW of average output power in mode-locked regime with a pump power of 7.3 W. To the best of our knowledge, this is the first report of a passively mode-locked Alexandrite laser using SESAM in general and quantum-dot SESAM in particular

Second Harmonic Generation with a Fractional Order of Periodical Poling

We demonstrate second harmonic generation in a diode-pumped periodically-poled lithium niobate crystal with a fractional poling period

Orange-to-red tunable picosecond pulses by frequency doubling in a diode-pumped PPKTP waveguide

A compact picosecond all-room-temperature orange-to-red tunable laser source in the spectral region between 600 and 627 nm is demonstrated. The tunable radiation is obtained by second-harmonic generation in a periodically poled potassium titanyl phosphate (PPKTP) multimode waveguide using a tunable quantum-dot external-cavity mode-locked laser. The maximum second-harmonic output peak power of 3.91 mW at 613 nm is achieved for 85.94 mW of launched pump peak power at 1226 nm, resulting in conversion efficiency of 4.55%

Broadly tunable quantum-dot based ultra-short pulse laser system with different diffraction grating orders

No abstract available

Innovation management strategy to promote the regional cooperation between China and Russia (case study of Moscow and Yiwu's Cooperation)

China and Russia are not only two major influential power in the world, but also the two largest economic transition countries. As a neighboring country, the cooperation of economic and trade between two sides not only has obvious geographical advantages, but highly complementary. With the in-depth cooperation in trade and economic of two countries,more and more direct cooperation between cities has taken place. In the past years, due to geographical advantages, the cooperation mostly took place in border cities, such as Heihe City and Blagovichensk City. With the new cooperation trend between China and Russia, more and more developed city of two countries begin to make cooperation, it's a new cooperation phenomenon that different from previous cooperation between border cities. In the process of cooperation, there are advantages and mutual interests, as well as difficulties and conflicts. Therefore the management of the cooperation of these cities also need innovation method. Therefore, it is urgent to analyze the problems and make research in this field. The previous researcher mainly focus on the analysis of the cooperation and management strategy between border cities of two countries which has been fully studied. However, there is less even almost no research analysis the current new cooperation situation between the economic center cities of two countries, including the problems exiting, further cooperation analysis, and future development trend as well as innovation management method to well promote the cooperation of them. © The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/)