Physical mechanisms of contact-electrification induced photon emission spectroscopy from interfaces

Photon emission during contact electrification(CE)has recently been observed,which is called as CE-induced interface photon emission spectroscopy(CEIIPES).Physical mechanisms of CEIIPES are essential for interpreting the structure and electronic interactions of a contacted interface.Using the methods of density functional theory(DFT)and time-dependent DFT(TDDFT),it is confirmed theoretically that the spectrum of emitted photons is contributed from electron transfer and transition during CE.Specifically,the excited electrons from higher energy state in one material may transfer to a lower energy state of another material followed by a transition;and/or some unstable excited electrons at a higher energy level of one material may transit to a lower energy state of itself,both of which result in CEIIPES.Furthermore,the CE-induced interface absorption spectrum(CEIIAS)has been demonstrated,due to the intermolecular electron transfer excitation.

Low-pump sum frequency generation of frequency- stabilized 453 nm blue laser for photonic quantum interface

Generation of a cavity-enhanced nondegenerate narrow-band photon pair source is a potential way to realize a perfect photonic quantum interface for a hybrid quantum network. However, to ensure the high quality of the photon source, the pump laser for the narrow-band photon source should be generated in a special way. Here, we experimentally generate the blue 453 nm laser with a sum frequency generation process in a periodically poled lithium niobate waveguide. A 13 mW laser at 453 nm can be achieved with a low-power 880 nm laser and 935 nm laser input, and the internal conversion efficiency is 21.6% after calculation. The frequency of a 453 nm laser is stabilized by locking two pump lasers on one ultrastable optical cavity. The single pass process without employ- ing cavity enhancement can ensure a good robustness of the whole system.