Session Index

We demonstrated the generation of polarization-entangled photon-pairs via the type-II spontaneous parametric down conversion (SPDC) process in domain-engineered titanium-diffused periodically poled lithium niobate waveguides (Ti: PPLN/W). The performance of the SPDC source has been tested using the classical sum-frequency generation (SFG) technique based on the SFG-SPDC analogy. The classical measurement results showed that the SFG conversion efficiency under a pump power of 0.319 mW and a conversion bandwidth (FWHM) of 0.43 nm is about 4.33 x 10-5, from which we estimated a SPDC photon-pair generation rate to be 2.69 x 107 Hz when a 20-mm long PPLN waveguide pumped by a 1-mW 785-nm laser was used. The quantum features of the generated cross-polarization photon source have been verified not only by the traditional quantum tomography and Hong-Ou-Mandel (HOM) interferometry, but also by a novel metasurface reconstruction methodology in both heralded single-photon and two-photon states. According to the HOM measurement results, we estimated this photon-pair source provides a 66.82 % purity in partially coherent state or an intermediate degree of entanglement. The reconstruction results illustrate the manifestation of multiphoton quantum interference on metasurfaces with the fidelity of 95.24 % and 98.54 % in the case of cross-polarized and twofold correlation photon-pairs.

 

We report our implementation of a squeezer, by generating squeezed vacuum state at 1064 nm through a bow-tie OPO cavity operated below the threshold. With the help of our home-made balanced homodyne detector (BHD), characterized with (CMRR) more than70dB, a noise reduction up to 10 dB is observed.

 

In contrary to the deterministic squeezing gate whose noise suppression performance never surpasses that of the ancilla, the probabilistic squeezing gate is proposed here to enhance the quantum noise squeezing with the help of photon addition and subtraction. The probabilistic squeezing gate finds widespread application in high-precision measurement.

 

We propose an all-optical control scheme to simultaneously realize parity-time symmetric and parity-time antisymmetric susceptibilities along the propagation direction of light by applying an external magnetic field. Through the interactions between fields and double-Lambda atomic system, the position-dependent susceptibility can be manipulated through the relative phase between interacting lights.

 

In this work, we have showed a VOA using DSM in a LC cell. Otherwise, for anyone spectral ,we could changed the attenuation intensity by reversibly switched the field strength .The VOA can block off visible or mid-infrared light when transmitting another under a specific biases.

 

Field-emitted electrons from a pulsed voltage up to 30 kV provided by a small Marx generator with a total energy of 88 mJ is used to generate x rays. Details of the Marx generator and the high voltage output will be presented. X-ray burst will be measured.