The frequency equation for the localized mode of one dimensional photonic crystal with a nonlinear defect is exactly derived by means of a transfer matrix method. The localized mode frequency depends on the localized light intensity. With the increase of the localized light intensity, the localized mode frequency will arise from the lower edge of the gap, then increase, and vanish near the upper edge of the gap for the case that Kerr coefficient is negative. When incident light frequency is given, with the varing incident light intensity, the system exhibits bistability. The bistability feature is due to the shifting of the localized mode frequency.

The adiabatic compression of ultrashort pulses from a DFB laser operating at 1550 nm in the fibers with slowly decreasing dispersion (FSDD) is investigated. High quality soliton compressions from 4.4 ps down to 1.1 ps in a 100 m FSDD and from 4.4 ps down to 830 fs in a 500 m FSDD are obtained. Furthermore, the results show that FSDD with more slowly decreasing can benefit to the pulse compression. Theoretical analyses are in good agreement with experimental results.

Deposition of Langmuir Blodgett and second order nonlinear optical properties of four naphthalocyanine derivatives were investigated by using second harmonic generation (SHG) technique. The mechanisms of nonlinearity were discussed simply. For asymmetrical naphthalocyanine, the origin of SHG was the electric dipole mechanism. For symmetrical naphthalocyanine, the origin of SHG was the magnetic dipole coupling mechanism. The maximal second order nonlinear optical susceptibility χ (2) was about 3.7×10 -8 esu for tri tert butyl cyan naphthalocyanine, which was 37 times more than that of tri tert butyl naphthalocyanine.

A first order quasi phase matched periodically poled LiNbO 3 (PPLN) for SHG with 6.5 μm period, 12 mm length, 10 mm width and 0.5 mm thickness has been successfully fabricated by applying an external electric field at room temperature from an high pulsed voltage generator. About 18 mW of CW 0.532 μm green light was obtained pumped by an 1.1 W of CW 1.064 μm Nd∶YAG laser with end coupling, which corresponds to 1.6% power conversion efficiency. The SHG normalized conversion efficiency is about 1.5% cm -1 W -1 , which shows 79% of the ideal nonlinear coefficient. A reasonable explanation of the experiment is given.

The effect of aberrations of fundamental wave on second harmonic generation especially on the phase of second harmonic (SH) wave is studied. The solution is applied to type Ⅰ second harmonic generation in KDP crystal. The results of intensity distribution and phase distortion in second harmonic generation are presented when the fundamental wave are Gaussian beams with aberrations of Zernike polynomials,and the effects of different aberration,walkoff and diffraction are analyzed. It is shown that different aberrations have different effects, which is mainly determined by the phase mismatching on the whole aperture; walk off effects bring large tilt and the more serious the effect the more distorted the phase of SH is; and effect of diffraction is neglectable. The approximative formula of SH phase distortion are given when both walkoff and diffration effects can be ignored.

The entangled state of atom cavity field is prepared based on the Jaynes Cummings model of two level atom cavity resonant interaction. Through changing the interaction times, the entanglement degree of the entangled state can be controlled. A scheme is proposed for teleportation of Schrodinger cat state of cavity field by using the non maximally entangled atom cavity states via the J C model with large detuning.