Aiming at a type of femtosecond optical solitary wave solution under arbitrary parameters discovered recently, the stability of the light pulse against some kinds of initial perturbations by employing numerical simulation is investigated. The results show that under the amplitude and wave shape perturbations the femtosecond pulse can propagate in a stable way and under the perturbations of random noise and chirp the light pulse can still propagate to a certain extension. These results will offer a theory support for the distortionless propagation of light pulse in optical fiber.

The beacon problem of adaptive optics (AO) is settled by the promotion of laser guide star (LGS), but the anisoplanatic error due to LGS will degrade the performance of AO system as well. Analytical expressions are given to evaluate the modal anisoplanatic error of atmospheric turbulence for LGS. Anisoplanatic error for Rayleigh LGS and Na LGS are also analyzed. Results show that the modal anisoplanatic error of 90 km Na LGS is obviously less than that of 15 km Rayleigh LGS without the angle deviation between LGS and object, but is greatly sensitive to the angle deviation than Rayleigh LGS. Good performance will be obtained with low order aberration mode correction in LGS AOS, and when angle deviation between beacon and object is larger than isoplanatic patch, low order modes should be corrected for effective correcting result.

A pair of fiber Bragg gratings with the wavelengths of 1562.11 nm and 1562.71 nm, respectively, are used as the end reflectors of a constructed linear cavity fiber laser. They are epoxied onto the upper and lower surfaces of an employed uniform density and thickness isosceles triangle cantilever beam axially. As a strain agent, the beam makes the wavelength shifts of both gratings be changeable, and therefore lead the laser producing pulses. The real time measurements of the frequency of the mechanical vibration applied on the free end of the beam are demonstrated by observing the pulses. Within the range of 0～6.1 mm, the amplitude of the vibration can be estimated by observing the wavelength shift difference between two gratings. The measured results have been demonstrated to be in good agreement with the actual values under the frequency of 100 Hz.

Supercontinuum generation from optical fibers with different group velocity dispersion (GVD) was simulated and calculated in details. It is found that flat and wideband supercontinuum cannot be obtained in anomalous and zero GVD regions because of fiber higher order nonlinearity (intrapulse Raman scattering) and higher order dispersion (TOD). Nevertheless, the broader and smoother supercontinuum spectrum can be obtained in normal GVD region. It is also found that a dispersion flattened fiber with small normal GVD is most suitable for flat and wideband supercontinuum generation. A super wide supercontinuum more than 300 nm with the spectral intensity fluctuation less than 10 dB was generated from such a fiber through increasing the pump power of the pulse.

A long period fiber grating (LPFG) is a band rejection fiber device with periodical retractive index modulation formed along the axis of the fiber core. Different with a fiber Bragg grating (FBG), it couples light from the forward propagating fundamental core mode into co propagating cladding modes at discrete wavelengths. Dependences of effective indices for fundamental core mode and cladding modes (HE1l/EH1l) upon wavelength, and the coupling constants between fundamental core mode and cladding modes (HE1l/EH1l) are studied. It is found that effective refractive indices for the core mode and cladding modes of LPFG both decrease with wavelength. Coupling constant formed with HE1l mode is much greater than that with EH 1l mode. Also coupling constants increase with the order of cladding modes at the lowest few ones. These differ with the conclusions drawn before.

According to analytic transfer matrix (ATM) method, it is possible to precisely determine the modal characteristics of a planar optical waveguide with arbitrary index profiles. An inversed analytic transfer matrix (IATM) method is presented to predict the refractive index profiles from measurement of mode indices, which has been proved to be valid even when solving some problems that inversed WKB method would find difficult.

Long period gratings (LPGs) will play an important role and be widely used in the fields of optical communication and optical fiber sensing. Many useful methods have been proposed to manufacture LPGs. However, there are some obvious disadvantages in these existing methods: high performance but high cost, or easy fabricating but low performance. To overcome these shortcomings, a novel technique is proposed for LPGs fabrication. In this method, a broad spectrum UV source is used instead of UV laser to write LPGs, and more than one LPG can be written simultaneously. As a result, it is easy to write LPGs with high performance, low cost and easy manufacturing. This technique can be used in industrial production of LPGs with very low cost.

By using Yb3+ doped double clad fiber with rectangular inner cladding and a set of back cavity mirrors with different transmission ratio, the double clad fiber lasers are constructed. It is found that the back cavity mirror with a higher transmission ratio is better, and the laser wavelength can be controlled by a back cavity. The relationship between slope efficiency and transmission ratio is in accordance with exponential function and the maximum slope efficiency is about 60%.

In this method, traditional standard plane in phase-measuring profilometry (PMP) was replaced by a calibration gauge containing three virtual calibration planes and a reference plane. The application of calibration gauge avoided precise translation of standard plane during calibration procedure. In addition, circular steps were designed to calibrate lateral coordinates automatically. With this calibration gauge, 3D coordinates could be calibrated through only one measurement. To recover the continuous phase distribution of all steps with the same height, an iterative procedure was proposed. Based on the known geometric parameters of calibration gauge and approximate estimation of equivalent wavelength, the fitted phase surfaces of three virtual calibration planes were adjusted to their ideal positions relative to the reference plane. Experiment results showed that this method was suitable for portable measurement systems using PMP.

By extending information theory to sampled imaging system, the performance of image gathering device is assessed according to mutual information . Information theory-based computer simulation results are given. Information theory-based design parameters which are used to optimize system are proposed. According to simulation results, the general matching features and ideal matching condition between optical imaging system and CCD detector array are obtained. Experimental results on image gathering verify the result of theoretical analysis and simulations.

A technique of reconstructing 3 D object shape by its measurement data using CGH is proposed. Firstly, both the range image and the intensity image of 3 D object are acquired simultaneously by using 3 D sensing system. Then, the Fresnel CGH is designed and fabricated. The problem of combining CGH with optical holography, an image hologram is recorded. This technique resolves how to obtain 3 D data in CGH as well as how to reproduce the object images in measurement of 3 D object shapes. The principle of the proposed method, the technology for designing and fabrication of the CGH and optical hologram and the experimental results are given.

In the generation and measurement of attosecond pulse using a few cycle laser pulse, the absolute phase of the laser pulse has been an important factor. The relation between the generation of attosecond pulse and the laser oscillation and how the absolute phase affects this relation are discussed. According to our calculation, the random of the absolute phase will not destroy the stability between the attosecond pulse and the laser oscillation. This result supports the direct measurement of the duration of the attosecond pulse with cross-correlation technique theoretically and gives an exact explanation for the experiment result in Ref.

The influence of laser polarization on the ionization parameters of Pd like Xe system including ionization rate, threshold intensity, residual energy in the laser field, relative population and original electron energy distribution are calculated and discussed. During calculation, the electron energy distribution based our establishing model is used. The calculated results show that laser polarization significantly effects the amplification of 41.8 nm 4d95d1S0-4d95p1P1 of Pd-like Xe and circular polarization is in favor of realizing the amplification of X ray laser at the same laser intensity.

Passive Q-switching of LD-pumped Nd: YVO 4 laser was demonstrated with a GaAs wafer as saturable absorbers in a plane-concave cavity. The pulse characteristics of passive Q-switched Nd: YVO 4 laser with a GaAs were measured. Q-switched pulse duration is 15 ns, pulse repetition rate is 470 kHz, beam quality M2 is equal to 1.31 and laser threshold of passive Q-switching is 500 mW. The numerical calculations of rate equations for case of GaAs playing the role as mentioned above are performed, and passive Q-switched mechanism and the dependency of pulse duration and pulse repetition rate on pumping rate are discussed. The calculated result was well in agreement with the experiments results.

Second harmonic and fourth harmonic are generated by Ti: sapphire laser pumped by a diode laser pumped Q switched, frequency doubled YLF laser at 527 nm. The nonlinear crystal LBO is used to generate the second harmonic in the Ti: sapphire laser cavity at type I phase match with birefringent filter respectively, and BBO is used to generate ultraviolet laser at 208 nm. The maximum average power of 410 mW at 415 nm, and 34 mW at 208 nm are obtained at 1 kHz repetition rate when the pumping power is 3.6 W. The relations between linewidth of fundamental wave and harmonic efficiency, and wavelength of fundamental wave and fourth harmonic efficiency, the effects of birefringent filter on pulse width and line width of Ti: sapphire laser, and the dependence of line width of Ti: sapphire laser with birefringent filter on pumping power are investigated in theory and experiment.

A monolithic ring laser and an external ring cavity for frequency doubling are used to generate 532 nm green radiation. With MgO: LiNbO 3 as a laser frequency doubling crystal, 249.5 mW second harmonic generation from 577 mW IR input power was obtained. The efficiency is 43.2% and power stability is better than 1%. Theoretical calculation is in good agreement with the experimental result.

In order to improve the coupling efficiency of the semiconductor optical amplifier with a single mode fiber, a model of a tapered rib semiconductor optical amplifier is presented. The effects of the index of waveguide region, the width of tapered-rib end waveguide, the structure of rib waveguide and graded refractive index (GRIN) waveguide on the expanded output mode of the tapered rib waveguide are studied and calculated by using the finite element method. Coupling efficiency of 95% for the tapered-rib semiconductor optical amplifier and the single-mode fiber is obtained by optimizing the structure of the tapered rib semiconductor optical amplifier.

The structural and optical properties of ZnS nanoparticles embedded in PVA films by an ion complexation method are reported. The results of TEM exhibit that the ZnS nanoparticles are well distributed in PVA films and their size can be controlled in the range of 2 nm～7 nm. ED analysis show that the ZnS nanoparticles have the similar structure of β-ZnS bulk material. Emission peaks of the nanoparticles vary in the range of 414 nm～440 nm at room temperature, depending on the experimental conditions. The relationships between ZnS nanoparticle morphologies and the PL emission peaks, intensity are emphatically discussed and their different mechanisms of luminescence are explored.

Under the environment of vacuum and cold black, the change in optical transmittance of JGS 3 optical quartz glass induced by radiation of protons with 140 keV was studied. When the radiation fluence exceeds 5×10 14 protons/cm 2, an absorption band in the wavelength range of 230～250 nm appeared and its peak increased with increasing the radiation fluences monotonously. Under higher radiation fluences, weaker absorption bands existed in the near ultraviolet and visible region. The color center E′ is responsible for the 230～250 nm absorption band. The E′ color center induced by proton radiation in the optical quartz glass is disturbed by hydrogen. During the radiation not only the breaking of Si-O bonds but also the transition from the and radicals into the and would occur.

The calculation of the beam waist diameter and it′s position of an intracavity Raman shift laser is discussed. We use optical transformation matrix and figure out the general pump field parameters in the Raman gain medium. And then, according to Ibison′s "matched mode" theory, the Stokes field parameters in the Raman active medium are calculated. By using the optical transformation matrix again, the Raman shifted beam (emitted from the optical system) parameters can be calculated. The results provide a new base for Raman shifted laser design.

The longitudinal electro optic effect and the multi dimensional isotropic acousto optic effect in square system and cubic system are researched. KDP of the square system and GaP of the cubic system are determinated as optimum crystals for multi dimensional isotropic acousto electro optic devices. Through calculating the function characters of acousto optic interaction in the two crystals, some optimum operating modes for its two dimensional, three dimensional and four dimensional isotropic acousto electro optic effect are determinated. The results will lay a foundation for design and manufacture this kind of devices. Multi dimensional acousto electro optic devices have applications in multi channel optic communication and optic signal processing.

The characteristic of thin film narrowband filters used in tilted incidence is described. The wavelength shift to shorter wavelength in a low index spacer filter for p polarization component is larger than that for s polarization component when filter is tilted. On the contrary, the shift in a high index spacer filter for p component is less than that for s component. Therefore the passbands of a tilted filter can be centered at the same wavelength for two polarization modes by means of using high and low index materials for a spacer, or selecting a moderate index material instead of a spacer. Designs of DWDM filters used for incident angle of 20°are presented, and the experimental results are discussed.

A series of materials such as Eu2+: CaAl2O4:, (Eu2+ ,Nd3+ ): CaAl2O4 were developed by using high temperature solid state reaction. The excitation, photoluminescence and afterglow spectra as well as the curve of afterglow decay were investigated. The role of doped rear earth ions and the long afterglow mechanism of this kind of phosphor are discussed.

Organic thin film electroluminescent devices with a novel distyrylarylenes derivative-4,4′-bis[2,2-(1-naphthyl,phenyl)vinyl]-1,1′-biphenyl (NPVBi) as an emitting layer have been prepared. The structures of these devices are: ITO/TPD/NPVBi/Alq3/LiF/Al, in which the thickness of TPD, the sum of NPVBi and Alq3 are kept at 50 nm. By adjusting the thickness of the NPVBi and Alq 3, in the device with the thickness of 30 nm NPVBi and 20 nm Alq 3, a good blue color purity of electroluminescence, of which the highest luminance is 708 cd/m 2, and the maximum luminous efficiency is estimated to be 1.13 lm/W, respectively, is achieved. It is proved that luminous properties of the devices can be controlled by the thickness of the emitting layer NPVBi and electron transport layer Alq3.

By using Ru(phen) 3Br 2 as the indicator, a fiber optic oxygen sensor based on fluorescence quenching has been developed. The weak fluorescence signal has been detected by the lock in technology and the detection of the concentration of oxygen has been achieved by detecting the hysteresis of phase shift. The sensor has the detecting limit of 5×10 -6 and the detecting accuracy of 5×10 -7 , and its response time is less than 10 seconds. It also has good reproducibility, stability and strong ability of immunity from disturbance.

A scheme of generating a two mode photon added SU(2) coherent field is proposed by means of performing conditional output measurement at the beam splitter. The influences of the added photon on atomic populations and the field′s non classical properties are investigated in the system of such a field interacting with a Λ type three level atom. It is pointed out that the added photon can alter atomic populations significantly. The photon number statistical distribution of one mode tends to sub Poissonian distribution while the other tends to super Poissionian distribution, the correlation between the two modes is enhanced and nonclassical correlation degree is increased.