Jianqi Shen

Influence of the signal light on the transient optical properties of a four-level EIT medium

Abstract General formulae for the transient evolution of the susceptibility (absorption) induced by the quantum interference effect in a four-level N-type EIT medium is presented. The influence of the signal light on the transient susceptibility for the probe beam is studied for two typical cases when the strength of the coupling beam is much greater or less than that of the signal field. An interesting level reciprocity relationship between these two cases is found.

CONSISTENT FORMALISM FOR THE MOMENTUM OF ELECTROMAGNETIC WAVES IN LOSSLESS DISPERSIVE METAMATERIALS AND THE CONSERVATION OF MOMENTUM

A new formalism for electromagnetic and mechanical momenta in a metamaterial is developed by means of the technique of wave-packet integrals. The medium has huge mass density and can therefore be regarded as almost stationary upon incident electromagnetic waves. A clear identification of momentum density and momentum flow, including their electromagnetic and mechanical parts, is obtained by employing this formalism in a lossless dispersive metamaterial (including the cases of impedance matching and mismatching with vacuum). It is found that the ratio of the electromagnetic momentum density to the mechanical momentum density depends on the impedance and group velocity of the electromagnetic wave inside the metamaterial. One of the definite results is that both the electromagnetic momentum and the mechanical momentum in the metamaterial are in the same direction as the energy flow, instead of in the direction of the wave vector. The conservation of total momentum is verified. In addition, the law of energy conservation in the process of normal incidence is also verified by using the wave-packet integral of both the electromagnetic energy density and the electromagnetic power density, of which the latter is caused by the interaction between the induced (polarized) currents and the electromagnetic wave.

Proposal of a broadband, polarization-insensitive and high-efficiency hot-carrier schottky photodetector integrated with a plasmonic silicon ridge waveguide

We propose a broadband, polarization-insensitive and high-efficiency plasmonic Schottky diode for detection of sub-bandgap photons in the optical communication wavelength range through internal photoemission (IPE). The distinctive features of this design are that it has a gold film covering both the top and the sidewalls of a dielectric silicon ridge waveguide with the Schottky contact formed at the gold-silicon interface and the sidewall coverage of gold can be easily tuned by an insulating layer. An extensive physical model on IPE of hot carriers is presented in detail and is applied to calculate and examine the performance of this detector. In comparison with a diode having only the top gold contact, the polarization sensitivity of the responsivity is greatly minimized in our photodetector with gold film covering both the top and the sidewall. Much higher responsivities for both polarizations are also achieved over a broad wavelength range of 1.2-1.6 mu m. Moreover, the Schottky contact is only 4 mu m long, leading to a very small dark current. Our design is very promising for practical applications in high-density silicon photonic integration.

Frequency-independent effective rest mass of photons in the two time derivative Lorentz material model

A physically interesting {\it effective rest mass} of photons in electromagnetic media, which is independent of wave frequency

Selective far-field addressing of coupled quantum dots in a plasmonic nanocavity

\omega

Focusing properties of a photonic crystal slab with negative refraction

, is defined in the present paper. It is verified that this frequency-independent effective rest mass of photons can be easily read off from the optical refractive index squared

Local field contribution to the optical properties of multilevel coherent atomic media

n^{2}(\omega)

Negative refraction and quantum vacuum effects in gyroelectric chiral medium and anisotropic magnetoelectric material

of commonly-seen electromagnetic media. As an illustrative example, we extract the frequency-independent effective rest mass of photons from

Anisotropic distribution of quantum-vacuum momentum density in a moving electromagnetic medium

n^{2}(\omega)

A Polarization-insensitive and high-efficiency Schottky Photodetector integrated with a silicon ridge waveguide

in the {\it two time derivative Lorentz material} (2TDLM) model. The connection between effective rest mass and electromagnetic parameters of electric permittivity (