The broadband fiber Raman amplifiers pumped by multi-wavelength laser diodes are numerically simulated by using average power analysis method. A new method to optimize the pumping configuration efficiently is proposed based on the characteristics of multi-pumped Raman gain spectra and the fact that different pumps have different impacts on the gain slope. A fiber Raman amplifier pumped by 10-wavelength source is optimized and the gain ripple less than 0.5 dB in 70 nm gain spectra is obtained.

A shipboard ocean lidar system, whose wavelength is 532 nm produced by a frequency doubled Nd∶YAG laser, was developed for measuring the concentration of ocean suspended matter. The Lidar system was installed on research vessel Dongfanghong Ⅱ, and the Lidar measurements of ocean suspended matter were conducted in Bohai Bay from August 28 to September 5, 2000. The concentrations of suspended matter were obtained at 18 sites by the Lidar. The results of Lidar measurements are in agreement with the that from in situ simultaneous sampling.

A new independent tuning method of the center wavelength and the bandwidth of fiber grating is demonstrated. The fiber grating is bonded to the side surface of elastic beam with a determinate angle along its axis direction. The center wavelength and the bandwidth of the fiber grating can be quasi-linearly tuned respectively through changing the torsional angle and the lateral displacement. In the experiments, it is demonstrated the quasi-chirp-free wavelength tuning of 8.28 nm and the bandwidth tuning of 5.32 nm in which the center wavelength is quasi-shift-free. The experimental results are in good agreement with the theoretical analyses.

The statistical characteristics of the first- and second-order polarization mode dispersion (PMD) is analyed by using Jones Matrix (JME) method, and the statistical regularity of PMD is derived. The scales of second-order PMD parameters to first-order PMD parameter are derived. It is instructive to simplify the measurement and compensation of second-order PMD.

A fiber optic displacement sensor based on the principle of collimated beam reflective intensity modulation is constructed. Both emitting fiber and receiving fiber are connected to graded-index (GRIN) lenses. The probe GRIN lens emits a collimated beam to illuminate a sample at an oblique incident angle. The receiving GRIN lens is then placed in the direction of specular reflection. Modulation functions are analysed for specularly reflective and Lambertian diffusive samples. Artificial calculation shows that the sensor has high signal level and flexibility in working distance and measurement range through adjusting the configuration parameters.

The basic theory of a rotatory optical fiber was discussed. The electromagnetic field components, fundamental parameters of the fiber were evaluated as the functions of the argument ε′ which is the rotatory element of the tensor dielectric coefficient matrix ε of the fiber. The calculating results were shown by the curves. In addition, a new expression about the relation between ε′ and bias magnetic field H b was demonstrated, by that the tensor dielectric coefficient of the rotatory optical fiber can be easily eveluated.

The PMD-induced pulse broadening may cause degradation of receiver sensitivity and has negative effects on the power spectrum of received signals. The effect of PMD-induced pulse broadening on receiver sensitivity, the effect of PMD on the spectrum of received power is analyzed, and the experiment results are provided. Finally, the scheme with which the power of a certain frequency component is extracted as a feedback control signal in a PMD compensation system is discussed.

The formulas for relayed three mirror anastigmat (TMA) are derived used for all reflective system, which is consisted of three aspherical surfaces. These relayed TMA can be considered in two conditions, one is formed by the primary mirror; the other is formed by the second mirror. Here the solutions for the two conditions are given. The results show that the optical systems with focal length of 4 meters, field of view 30 are suitable to the two conditions.

Based on the theoretical analysis of the electron hologram, a spatial filtering method to avoid the overlap of the digital reconstructed images of electron hologram is proposed. In this method, we make Fourier transform of the detected electron hologram and filter the obtained spatial spectrum, then generate a new electron hologram by making inverse Fourier transform of the filtered spatial spectrum. The overlap of the reconstructed images of electron hologram is avoided when the obtained new hologram is digitally reconstructed with the usual digital method.

A new optical encryption technique based on computer-generated hologram of double fractional Fourier transform is presented. In this method, the fractional Fourier transform hologram of several images with different orders are respectively recorded on one plate, which means each image has its own fractional order. In order to reconstruct the encoded images, several fractional Fourier transform systems with certain orders are needed. Because of its particularity of image reconstruction, it is regarded as a new optical security system and can be used in anti-counterfeiting.

For super high precision non-contact measurement of miniature cavities, an optical focus detection system is proposed based on a differential confocal microscopy. This system combines a high axial resolution and absolute position traceability of a confocal microscopy with a small gradient-index lens. The differential confocal principle and the system configuration are presented. In this system, the small detector with 1 mm diameter is obtained by a gradient-index lens, the noise produced by the light source intensity drift and the detector electronic drift is eliminated, and signal-to-noise ratio and axial resolution are increased by differential design of two detectors. Measurement made with 20° degree gauge block, with a detector of 1 mm diameter, axial resolution is up to 5 nm.

Frequency of diode laser is stabilized by using saturated absorption spectroscopy. High signal-to-noise ratio of differential error signal of saturated absorption spectroscopy is achieved by designing and optimizing the servo loop, thus the sensitivity of frequency locking and long-term frequency stability are improved. This system may be used to the realization of laser cooling and trapping of rubidium atoms.

The photoluminescence of Au 2S/Au nanoshell (a nanometer-scale Au 2S core coated by a thin Au shell) is observed. A photoluminescence peak of Au coated Au 2S is observed near the blue-green region. Comparing to the photoluminescence region of bulk Au 2S which is near the orange-red region, the blue-shift photoluminescence of the Au 2S/Au nanoshell mainly attributes to the core/shell nanostructure.

The influence of C 60-toluene derivative on the photoelectric properties of CuPc/C60 films is studied, and the mechanism is discussed. According to the relationship of photoconductivity and illuminated time, the instantaneous photoconductivity spectra and photoinduced discharge curve (PIDC), it is found that the photoconductivity of the CuPc/C60 films doped with C60-toluene derivative has increased by one order of magnitude in several seconds.

Absorption spectra, emission spectra of Er3+ and Yb3+ codoped tellurite glasses were studed. Er3+ upconversion mechanism in tellurite glass was analyzed. The Judd-Ofelt strength parameters Ω t(t2,4,6), which are Ω 24.74×10 -20 cm2, Ω 41.46×10 -20 cm2, Ω 6 0.64×10 -20 cm2 respectively, were calculated by Judd-Ofeld theory. Spontaneous radiative rate and branch ratios of each energy levels of Er3+ ions were given. Stimulated emission cross section was calculated by McCumber theory, and was compared with other host glasses.

A generalized method is proposed for computing the off-axes extinction ratio of Solc birefringent filters. Based on the result, the conoscopic figures of Solc birefringent filters are simulated, and the curves of integral extinction versus wavelength and incident angular aperture are presented in the case of diffusive incidence. The calculated values agree well with the experimentally obtained values given here. Moreover, the method is suitable for computing the off-axes extinction ratio of all kinds of birefringent filters.

new technique for fabrication of continuous microoptical elements by using LCD (liquid crystal display) real-time mask is proposed, and its principle and design method are expatiated. Based on partial coherent imaging theory, the process to fabricate the micro-axicon and the microlens has been simulated. The experimental setup for LCD real-time mask technique was built by using the color LCD in authors′ laboratory. and the micro-axicon array has been fabricated. The 3|dimensional surface relief structure was shaped in the pan chromatic silver-halide sensitized gelatin (Kodak-131) with trypsinase etching. The caliber of axicon is 118.7 μm, and the etching depth is 1.322 μm

The influence of arc noise to laser strip image is studied comprehensively, and the arc noise model is established. Originating from the principles of projective and perspective transformation, the models of coordinate transformation between workpiece and camera with arbitrary angle of laser light and camera are presented. Both of the models are very useful to the design of structure light sensor. The sensor designed based on the theory above is used in automatic welding.

The power density spectrum of an inner-phase-modulated optical fiber resonator is analyzed theoretically and experimentally, which is valid for any source coherence time. The results indicate that fast modulation can flat the resonant peaks of the resonator's spectrum, while weak modulation does not.

Basing on the conventional Kellner eyepiece, four hybrid refractive|diffractive eyepieces with different locations of the diffractive surface are designed. Only a kind of glass K 9 is used in the optical systems. The optical performance of the hybrid eyepieces are studied and compared with the Kellner eyepiece. It has been shown that the hybrid eyepieces take the advantages of improving aberrations, such as astigmatic, lateral color, transverse aberration, longitudinal aberration and chromatic focal shift, as compared with the Kellner eyepiece, and a satisfactory distortion can be obtained if a suitable location of the diffractive surface is chosen. The size and the weight is greatly reduced due to the introducing of diffractive surface.

Based on the fast Fourier transform (FFT) algorithm, the wave-front reconstruction algorithm of Shack-Hartmann sensor is described. The fast Fourier transform is used to diagonalize and decouple the wave-front reconstruction equations which is deduced from the least-squares criterion. The algorithm is accurate and stable. And the superiority of real-time be comes notable when the Shack|Hartmann sensor′s spatial resolution is getting higher.

The two methods measuring Einstein-Podolsky-Rosen (EPR) correlation of continuous variables, the balanced homodyne detection and the direct measurement for Bell-state are analytically discussed. In the two detection systems the designated reference levels for the quantum correlation measurement are different, so the displayed results on the spectral analyzer are not identical. After implementing a transformation to the reference level the measured squeezing of coupled mode, EPR correlation and the relation expression between them are totally same. The measurement principle of the two methods is theoretically analyzed and their characteristics are discussed from the requirements of experiments.

Realizing the teleportation of a quantum state, specially the teleportation of a many-qubit quantum state, is of great importance in quantum information. A scheme of teleporting a two-qubit unknown atomic state is proposed. In this scheme, two pairs of entangled states are used as quantum channel instead of using a three-particle entangled state. And this scheme can also be generalized for the teleportation of the N- qubit atomic state.

The interaction of coupling three-level atoms with cavity field is studied. The differential equations discribing the dynamic behaviors of the system for three kinds of atom level configuration called Λ, Ξ and V are derived . The case of Λ type with degenerate lower levels is discussed in detail. The effects of the coupling strength between the atoms, the initial states and detuning on the time evolutions of the system are analyzed.

Based on the numerical analysis of spatial different three-position-pumped situations, the research was carried out on the Yb-doped double-cladding fiber laser containing amplified spontaneous emission. The results show the different laser distribution and power characteristics for different three-position-pumped situations, even ignoring the reflection of the resonator to the pump light.

An autocorrelator based on ZnSSe two-photon absorption (TPA) photodetectors is demonstrated. The autocorrelator has a broad spectral response range of 400～800 nm. By using a ZnMgS TPA photodetector which is more sensitive to UV laser, the autocorrelator′s response range can be extended further to the ultraviolet waveband.