Two-photocurrent devices

Absolute calibration of photodetectors: photocurrent multiplication versus photocurrent subtraction

We report testing of the new absolute method of photodetectors calibration based on the difference-signal measurement for two-mode squeezed vacuum by comparison with the traditional absolute method based on the coincidence counting. Using low-gain parametric down conversion we have measured the quantum efficiency of a counting detector by both methods. The difference-signal method was adapted for the counting detectors by taking into account the dead-time effect.

Spatio-temporal dynamics of shift current quantum pumping by femtosecond light pulse

Shift current---a photocurrent induced by light irradiating noncentrosymmetric materials in the absence of any bias voltage or built-in electric field---is one of the mechanisms of the so-called bulk photovoltaic effect. It has been traditionally described as a nonlinear optical response of periodic solids to continuous wave light using a perturbative formula, which is linear in the intensity of light and which involves Berry connection describing the shift in the center of mass position of the Wannier wave function associated with the transition between the valence and conduction bands. We an…

石墨烯中双色激光控制光电流与高次谐波

Two-color laser control of photocurrent and high harmonics in graphene

本研究通过数值求解量子主方程，全面探究了石墨烯中双色激光驱动的光电流与高次谐波产生，发现通过调节激光参数可定量控制二者，并揭示了其动力学对称性机制。