A novel method which can directly measure the zero-dispersion wavelength of a single-mode fiber is presented. It consists of copropagating a train of pump pulse with a cw light in an optical fiber. The pump wavelength is located at the normal-dispersion regime of the fiber while the cw wavelength is tunable. The interplay between cross-phase modulation and group-velocity dispersion results in intensity modulation on the cw light which can evolve into a train of bright or dark pulses depending on whether its wavelength is tuned into the anomalous- or normal-dispersion regime of the fiber. If neither bright nor dark pulses are generated, then the cw wavelength must be near the zero-dispersion wavelength of the fiber. By using this simple method, the zero-dispersion wavelength of a 0.98 km dispersion-shifted fiber have successfully been measured with a wavelength accuracy of ～0.5 nm.

A kind of uniform density and thickness isosceles triangle cantilever beam is designed to realize linear tuning of Bragg wavelength of fiber grating without chirping by adjusting the deflection of the free end that is the vertex part of the triangle. The tuning is demonstrated experimentally within the range of 4.5 nm. After introducing a correction index η=0.71, experimental results agree with the theoretical value. The form of the reflected spectrum is related to the quality of pasting between fiber Bragg grating and the beam.

Using the self consistant field (SCF) method, the channel light waveguide problem was solved and the propagation constants with 10 significant figures were obtained. It proves that a simple SCF method for this problem is superior very much to the finite element method (FEM) and the others, both in acurracy and in caculating time, and that it should be used in the advanced light waveguide design. Moreover, the causes why the SCF method can reach high accuracy and the FEM can′t be improved ultimately are discussed in detail.

With the development of optical fiber communication, the photorefractive functional waveguie gratings are being widely utilized in a great variety of devices and systems. A novel two-beam holographic approach, including a space beam and a guided-wave beam, for fabricating a photorefractive grating on Ti:LiNbO3 channel waveguides is proposed. The theoretical analysis of the experiemntal results show that the approach is practical and effective. This approach can be also used for fabricating the surface-relief waveguide gratings. It is a flexible means to fabricate various functional gratings with a grating-period shorter than the half-wavelength of the exposure light and the chirped-grating.

The statistical criterion to decide whether there is signal burying in noise has been analyzed, and the statistical processing method of photon image has been studied to increase the s/n ratio. Image quality is improved. The probability of detection of ultra-weak bioluminescence in the photon count imaging system and limit of detection of photon image are discussed.

Minimal distance measure method based on an absolute difference measure is applied to the similarity measure among the optical correlation resultant images, and then the similarity conclusion between the image to be tested and the reference image can be deduced. By this method, the false recognition which often occurs when the traditional correlation peak thresholding method is used, can be avoided and the recognition accuracy can be greatly improved. Even the low quality correlation output between two gray scale images can be processed so that the complex preprocessing of the gray scale images, such as the binarization and encoding, can be omitted. The optical experimental results implemented on an incoherent optical correlator are given.

The phase error caused by sampling the fringe patterns in practical Fourier-transform profilometry is discussed. Another kind of spectrum overlapping is analysed that is caused by the discrete Fourier-transform (DFT). The criterion for the selection of sampling frequency is derived. The computer simulations and experiments verified the theories.

The serious disturb caused by atmosphere turbulence can be eliminated effectively and the astronomical image reconstruction with the diffraction-limited resoluiton of the telescope can be achieved by the spectrum masking. The key problem is to recover Fourier phase spectrum. Some actual problems that will be faced when to recover object phase spectrum from the bispctrum with a micro-computer are discussed, including the huge information of the bispectrum contradict the limited storage space of the micro-computer; the area and the path of phase recurring; phase wrapping and error accumulating in phase retrieving from the bispectrum. The corresponding methods used to solve these problems and the experimental result of image reconstruction for astronomical objects are given respectivly.

A theoretical model, in which the band transport equations and the coupled wave equations are both considered, to describe the characters of recording and thermal fixing in LiNbO3 is presented. It is found that in simultaneous-fixing, the existing ionic grating affect the writing of the electronics grating by reducing the coupling gain and the grating envelope of the fixed index grating by simultaneous fixing is quite uniform inside the photorefractive crystal with comparison to by post-fixing. The resulting diffraction efficiency of the fixed volume grating is mainly dependent on the initial intensity modulation of the two writing beams. The model also shows that fixing in a high doped material, at its developing stage, the electric grating can not be erased which resulting in low diffraction efficiency. A set of experimental demonstration are presented.

The signals emitted from the ring-down cavities under differnt conditions were investigated using pulsed light from an optical parametric oscillator. The ring-down signals coupled with complicated modulations were observed in the experiment. Some of the mode frequencies can be explained by the formula deduced from the eigenmode theory of resonant cavity. It is proposed that the complicated mode beating was due to the slight splitting of the transverse mode owing to the astigmation and aberration of the ring-down cavity optical system.

Proximity effect is an important factor which limits optical lithography resolution, and it also limits the applications of laser direct writing system in submicron and half-submicron optical lithography. The production mechanism of proximity effect in laser direct writing is analyzed, its differences with projection optical lithography and electron beam lithography pointed out, and a convenient and effective optical proximity correction (OPC) method presented. The experimental results show that the feature size of 0.6 micron can be got by using OPC method in ISI-2802 laser direct write system.

A novel laser heterodyne interferometer used for on-line measuring surface roughness has been developed. It features compact volume (25 cm×20 cm×10 cm) and excellent immunity to environmental disturbances. The system employs a frequency-stabilized laser diode. The design of common path makes the measurement beam and the reference beam incident on the surface along the same way. The processing method of heterodyne signals combines integer measurement with fraction period measurement, so it has wide dynamic range and high resolution. In addition, critical angle method is introduced for automatic focusing. The height and lateral resolutions of the system are 0.39 nm and 0.73 μm respectively. The maximum range of automatic focusing is ±0.5 mm and the focusing accuracy is 1 μm within ±25 μm of the focus. The stability during 80 minutes is 1.95 nm (3σ).

An alternative implementation of confocal scanning microscopy has been developed to construct a compact and anti-jamming confocal microscope by using fiber optical components. A fiber optical confocal scanning microscope (FOCSM) in reflected mode was bulit for this purpose. The influence of fiber-collective lens parameter A and numerical aperture of objective lens on the system imaging resolution is analyzed. Consequently, an optimum collective lens was chosen to improve the system resolution with certain fiber and objective lens. In system testing, submicron transverse resolution and micron axial section resolution with good imaging stability has been obtained. The instrument will be used for three-dimensional imaging of the microstructure in the fields of material sciences, biology and medicine.

the characteristic of thermal induced non-reciprocal phase noise was analyzed theoretically, and the temperature distribution model was derived for the fiber sensing coil. The zero point drift of the fiber optic gyros (FOG) induced by outside temperature fluctuation was simulated numerically and compared with the four types of fiber sensing coil manufacture methods (ZYL, SYM, DIP, QUA). The related zero point drift compensated method was proposed.

A 0.022 mol fraction doped Cr:LiSAF crystal with 1 mm in thickness is pumped by a 679 nm laser diode, and NCPM KN crystal is used as intracavity doubler. Maximal output of TEMoo 3.15 mW of blue laser at 431.7 nm is obtained with the absorption power of 256 mW. The laser scheme shows a threshold of 96 mW and slope efficiency of 1.97%. Continuous-wave tunable output is demonstrated in the blue region of 423.4～445.5 nm only by changing temperature of KN crystal.

Characteristics of distributed Bragg reflector (DBR) fibre lasers are analyzed by means of coupled-mode theory and numerical method. The threshold gain spectrum of DBR lasers with different gratings are compared with each other. It provides theoretical guidance for design and fabrication.

A simplified model is established to describe the electron energy distribution in circularly polarized optical-field ionized plasmas, based on quasi-static tunneling ionization theory. Comparisions with existing calculations and experimental result show that it can be used to study OFI plasmas with higher electron temperature and/or lower electron density.

On the basis of Hamiltonian derived in the references under the dipole and rotating-wave approximations, the energy spectrum of ionic-crystal lattice vibration anharmonicly in lightfield is discussed. The energy level as the total number n of photons and optic phonons with the same mode-frequency splits up into sublevels via the photon-phonon and phonon-phonon coupling, which would be a kind of dynamical (A.C.) Stark effect. We found a purely quantum effect: the n=0 (vacuum) level is shifted by the interaction between phonons themselfs. It is expected that spectrum calculated might be another resource of information for crystal structure.

The overlapped Gauss field can get large-range homogeneous field. The overlapped 1-D Gauss field is carefully analyzed and compared with general Gauss field in the intensity homogeneity, utilization ratio of luminous energy and average optical intensity. The analysis results show that a well homogeneous overlapped Gauss field intensity is gotten with satisfactory utilization ratio of luminous energy.

The Hartmann-Shack(H-S) wavefront sensor is the most popular type in adaptive optics system operated with faint object, because of its outstanding advantages in high light efficiency, simple structure and large capacity of channels. The characters and accuracy of ICCD and CCD type H-S wavefront sensors operated with faint objects is deeply analyzed and compared. The algorithm for quantitative analysis is derived, and the experimental results are presented as well. All of these are useful for selection of technical scheme and engineering design of this kind of wavefront sensor operated with faint object.

The output of electric current sensor employing twisted fibre may suffer from variation of ambient temperature or other perturbations such as pressure and vibration. A new compensation method for such perturbations is proposed and demonstrated in this paper for ac current detection. In the experiment, the shift of the initial bias phase of the current sensor is simulated by changing the azimuthal angle of the linearly polarized light at the fibre input, and the validity of the compensation method is verified experimentally. This method is able to compensate arbitrary shift in sensor bias phase.

A general calculation method to obtain the transmission spectrum of Faraday anomalous dispersion optical filter (FADOF) is presented. The theoretical scheme can be applied to any electrical dipole transmission of various atomic vapors and is valid for arbitrary magnetic fields. Moreover, the method can be used to predict the performance of both the passive FADOF and excited state FADOF (ESFADOF). It can also be extended to calculate the transmission spectrum of other new type atomic optical filters (such as Stark type atomic optical filters). The theoretical transmission curve of Rb 775.9 nm ESFADOF obtained by the general method is given, which agrees well with the experimental result.

The multilayered X-ray Bragg-Fresnel optics is fabricated with the zone plate profile formed on the phptoresist on a surface of multilayer mirror by optical holography and followed by ion beam etching into the multilayer mirror. The meansured results of the fabricated Bragg-Fresnel optics are presented. The measured results show that the method is suitable for making Bragg-Fresnel optics.

The athermalism of diffractive optical elements in infrared hybrid refractive-diffractive optical systems is analysed. It is shown that diffractive optical elements contribute a little to the thermal effects but their achromatic characteristic plays an important role in athermalization of infrared hybrid refractive-diffractive optical systems. An infrared hybrid refractive-diffractive optical system for 3～5 μm band with short total track is designed and discussed.

The dynamic problem of interaction between a 2-level atom and double modes field is analyzed. It dealt with the process of exchange of momentum between the field and the atom. More photons could be absorbed or emitted when number of photons is controlled. Thus large translation of atomic mass center momentum is realized.

Two modes polarization-controlled photorefractive switches are proposed. Analytical equation of the diffraction efficiency ratio on readout with extraordinarily polarized and ordinarily polarized beams is deduced. It is demonstrated that the diffraction efficiency of the photorefractive hologram is relevant to the polarization of the readout beams, and this diffraction efficiency ratio can range from 80%～90%, this property can be used to implement the switches.

Based on the linear relationship between the logarithm of the central peak energy and k2⊥ in light scattering, a method for the measurement of surface roughness by changing the wave vectors is proposed. Experimental measurements of 6 samples of silicon backsides were conducted