研究目的
Investigating the generation of entangled photons without momentum conservation using a microscale source of lithium niobate.
研究成果
The study successfully demonstrated the generation of entangled photons without momentum conservation using a microscale source of lithium niobate. The nonphase-matched SPDC resulted in a frequency spectrum an order of magnitude broader than that of phase-matched SPDC, with strong two-photon correlations preserved due to energy conservation. This opens up new possibilities for investigating fundamental quantum effects and practical applications in quantum imaging, quantum key distribution, and quantum metrology.
研究不足
The efficiency of nonphase-matched SPDC was much lower than for phase-matched SPDC in a macroscopic crystal, and fluorescence became the dominant process in the spectral region of interest. The spectral range of SPDC could not be fully obtained due to the narrow tuning range of the seed.
1：Experimental Design and Method Selection:
The experiment utilized a planar geometry source, a 6 μm thick layer of lithium niobate, to generate entangled photons without phase matching. The design exploited the position-momentum uncertainty relation to alleviate the need for momentum conservation.
2：Sample Selection and Data Sources:
The sample was a thin layer of magnesium oxide doped lithium niobate on a 500 μm fused silica substrate. The thickness of the sample varied from 5.9 μm to 6.8 μm.
3：9 μm to 8 μm.
List of Experimental Equipment and Materials:
3. List of Experimental Equipment and Materials: The setup included a Hanbury Brown–Twiss setup for correlation measurements, a spectrometer for fluorescence spectrum measurement, and single-photon detectors.
4：Experimental Procedures and Operational Workflow:
The experiment involved measuring the normalized second-order correlation function, the coincidence rate as a function of pump power, and the spectral bandwidth using the single-photon spectroscopy method.
5：Data Analysis Methods:
The joint spectral intensity (JSI) was reconstructed using stimulated emission tomography (SET) to demonstrate the high degree of frequency entanglement.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
