Sidorenko Pavel, Kozlov Maxim, Bahabad Alon, Popmintchev Tenio, Murnane Margaret, Kapteyn Henry, Cohen Oren
Solid State Institute and Physics Department, Technion–Israel Institute of Technology, Haifa 32000, Israel.
Opt Express. 2010 Oct 25;18(22):22686-92. doi: 10.1364/OE.18.022686.
We show that a sawtooth phase-modulation is the optimal profile for grating assisted phase matching (GAPM). Perfect (sharp) sawtooth modulation fully corrects the phase-mismatch, exhibiting conversion equal to conventional phase matching, while smoothened, approximate sawtooth structures are more efficient than sinusoidal or square GAPM modulations that were previously studied. As an example, we demonstrate numerically optically-induced sawtooth GAPM for high harmonic generation. Sawtooth GAPM is the most efficient method for increasing the conversion efficiency of high harmonic generation through quasi-phase-matching, with an ultimate efficiency that closely matches the ideal phase-matching case.
我们表明，锯齿形相位调制是光栅辅助相位匹配（GAPM）的最佳分布。完美（尖锐）的锯齿形调制能完全校正相位失配，其转换效率与传统相位匹配相当，而平滑的近似锯齿形结构比先前研究的正弦或方形GAPM调制更有效。例如，我们通过数值模拟展示了用于高次谐波产生的光学诱导锯齿形GAPM。锯齿形GAPM是通过准相位匹配提高高次谐波产生转换效率的最有效方法，其极限效率与理想相位匹配情况非常接近。
