CAJ | 학술논문

纠缠源亮度和品质直接决定其作为量子信息处理资源的应用价值，研究参量转换过程中纠缠对的产生效率和品质随泵浦激光强度的变化关系对制备高品质纠缠源具有基础意义。利用参量下转换、极化后选择和符合计数技术，制备了Einstein－Podolsky－Rosen（ EPR）偏振纠缠态。研究了泵浦激光强度对纠缠光子产生效率、对比度和保真度的影响。结果表明，随泵浦激光强度增大，纠缠对产生效率保持不变，也即纠缠源亮度随激光强度增大而线性增大；纠缠光子的对比度、保真度随激光功率增大而下降。
규전원량도화품질직접결정기작위양자신식처리자원적응용개치，연구삼량전환과정중규전대적산생효솔화품질수빙포격광강도적변화관계대제비고품질규전원구유기출의의。이용삼량하전환、겁화후선택화부합계수기술，제비료Einstein－Podolsky－Rosen（ EPR）편진규전태。연구료빙포격광강도대규전광자산생효솔、대비도화보진도적영향。결과표명，수빙포격광강도증대，규전대산생효솔보지불변，야즉규전원량도수격광강도증대이선성증대；규전광자적대비도、보진도수격광공솔증대이하강。
The brightness and quality directly determine the application value of entangled photons as resource of quantum information processing.In parametric conversion process, study on the relation between pump laser in-tensity and the produce efficiency and quality of entangled photons has basic significance to the preparation of high quality entanglement source.Using spontaneous parametric down conversion, the polarization post selection and the technique of coincidence counting, the polarization Einstein-Podolsky-Rosen ( EPR) entangled states have been prepared.The effects of the pump laser intensity on the efficiency, contrast and fidelity of the entan-gled photons have been studied systematically.The results show that with the increase of the pump laser intensi-ty, the generation efficiency of entangled photons is almost invariable, namely the entanglement source brightness increases linearly with the laser intensity.On the other hand, the contrast and fidelity of the entangled photons decrease with the increment of laser power.