Xiao-Jing Liu

Function photonic crystals

Abstract In this paper, we present a new kind of function photonic crystals (PCs), whose refractive index is a function of space position. Conventional PCs structure grows from two materials, A and B, with different dielectric constants e A and e B . Based on Fermat principle, we give the motion equations of light in one-dimensional, two-dimensional and three-dimensional function photonic crystals. For one-dimensional function photonic crystals, we give the dispersion relation, band gap structure and transmissivity, and compare them with conventional photonic crystals, and we find the following: (1) For the vertical and non-vertical incidence light of function photonic crystals, there are band gap structures, and for only the vertical incidence light, the conventional PCs have band gap structures. (2) By choosing various refractive index distribution functions n(z), we can obtain more wider or more narrower band gap structure than conventional photonic crystals.

The effect of defect layer on transmissivity and light field distribution in general function photonic crystals

We have theoretically investigated a general function photonic crystals (GFPCs) with defect layer, and choose the line refractive index function for two mediums A and B, and analyze the effect of defect layers position, refractive indexes, period numbers and optical thickness on the transmission intensity and the electric field distribution. We obtain some new characters that are different from the conventional PCs, which should be helpful in the design of photonic crystals.

Light field distribution of general function photonic crystals

Abstract In this paper, We have presented a new general function photonic crystals (GFPCs), which refractive indexes are line functions of space position in two mediums A and B , and obtain new results. (1) When the line function of refractive indexes is up or down, the transmissivity can be far larger or smaller than 1. (2) When the refractive indexes function increase or decrease along the direction of incident light, the light intensity should be magnified or weaken, which can be made optical magnifier or attenuator. (3) The GFPCs can be made optical diode when the light positive and negative incident the GFPCs.

Transmission character of general function photonic crystals

Abstract In the paper, we present a new general function photonic crystals (GFPCs), whose refractive index of medium is a arbitrary function of space position. Unlike conventional photonic crystals (PCs), whose structure grows from two mediums A and B , with different constant refractive indexes n a and n b . Based on the Fermat principle, we give the motion equations of light in one-dimensional GFPCs, and calculate its transfer matrix, which is different from the conventional PCs. We choose the linearity refractive index function for two mediums A and B , and find the transmissivity of one-dimensional GFPCs can be much larger or smaller than 1 for different slope linearity refractive index functions, which are different from the transmissivity of conventional PCs (its transmissivity is in the range of 0 and 1). Otherwise, we study the effect of different incident angles, the number of periods and optical thickness on the transmissivity, and obtain some new results different from the conventional PCs.

Quantum Wave Equation of Photon

In this paper, we give the quantum wave equations of single photon when it is in the vacuum and medium. With these wave equations, we can study light interference and diffraction with the approach of quantum theory, and also can study the quantum property of photon when it is in a general crystal and photonic crystal. Otherwise, it can be applied in quantum optics and condensed matter feld.

Two-dimensional function photonic crystals

In this paper, we have firstly proposed two-dimensional function photonic crystals, which the dielectric constants of medium columns are the functions of space coordinates

Finite Temperature Schrödinger Equation

\vec{r}

Electromagnetically induced grating based on the giant Kerr nonlinearity controlled by spontaneously generated coherence

, it is different from the two-dimensional conventional photonic crystals constituting by the medium columns of dielectric constants are constants. We find the band gaps of two-dimensional function photonic crystals are different from the two-dimensional conventional photonic crystals, and when the functions form of dielectric constants are different, the band gaps structure should be changed, which can be designed into the appropriate band gaps structures by the two-dimensional function photonic crystals.

Quantum Wave Equation of Non-conservative System

We know Schrödinger equation describes the dynamics of quantum systems, which don’t include temperature. In this paper, we propose finite temperature Schrödinger equation, which can describe the quantum systems in an arbitrary temperature. When the temperature T=0, it become Shrödinger equation.

The Quantum Well of One-Dimensional Photonic Crystals

We propose a scheme for realizing electromagnetically induced grating via the giant Kerr nonlinearity in a coherently driven four-level system with spontaneously generated coherence. In the presence of spontaneously generated coherence, Kerr nonlinearity can be enhanced with vanishing linear absorption. Thus, with a standing-wave coupling field, one can achieve a pure absorption grating, which leads the probe field to gather the zero-order direction when the detuning of the coupling field is on resonance. Moreover, we can obtain a pure phase grating, which diffracts a weak probe light into the first-order direction and the second-order direction when the detuning of the coupling field is off resonance.