In this paper, we report the experimental results of oscillation in erbium doped fiber (EDF), due to the considerable optical reflection caused by the near end defects. The oscillation occurs at the peak ASE wavelength, which might be equal to the peak gain wavelength in long erbium doped fibers, and is harmful to the gain characteristics of EDF amplifiers.

On the base of the composited waveguide theory, the characteristics of coupled optical power and poarization in the coupling region of a overlong coupler have been analyzed, and a new mothed to fabricate single mode optical fiber dual window narrowband wavelength division multiplexers(NWDM) is proposed and demonstrated experimentlly. Three fabricated devices, operating at 1300 nm, 1550 nm mono window, and 1300 nm/1550 nm dual window, respectively, show spacing channel of 14 nm, channel bandwidth of 2～3 nm, adjacent channel isolation 20 dB, <0.1 dB polrization sensitivity, and <0.5 dB optical loss. These specifications are the best performances reported to-date for the NWDMs.

A parallel recursive algorithmdiscrete-time cellular neural network is proposed. A hole filling template is designed based on comparison principle of ordinary differential equations. An optoelectronic system in terms of spatial area coding method and defocused multiple image scheme is constructed for execution.

An encoding method for constructing trinary interconnection weights based on the rule of least-lost of information is proposed in this paper. The encoding method improves the limitation on the accuracy of optical interconnection and is potential for optical implementation. The performance of ONN is evidently improved by this encoding method compared to the other methods proposed before. A detailed description of this method is presented.

A method is propose in this paper for high sensitive absorption spectrum analysis using intensity difference squeezed light. It has been evidence with a semiclassical theoretical calculation that the sensitivity of measurement can be beyond the limit set by vacaum fluctuation and the minimum detectable absorptance is below the SNL.

The Raman excitation plus laser induced electromic fluorescence (RELIEF) method has been modified, so that it can been applied in measureing the multiple points intantaneous velocities of a supersonic or subsonic air flow. The measurement accuracy is better than two per-cent.

Some results of our study on single frequency, narrow linewidth fiber grating external cavity semiconductor laser are reported in this paper. The effects of external cavity feedback on the threshold gain and emission linewidth are discussed theoretically; Laser emission with side mode suppression ratio more than 25 dB, spectrum linewidth narrower than 60 kHz is realized at 1.55 μm wavelength region experimentally by coupling a conventional multimode semiconductor laser with a fiber Bragg reflective (FBR) filter fabricated by ourselves.

The extraction efficiency and the distribution of population inversion in multi pass amplifier are calculated theoretically. The calculated results consist with the experimental results coaxial double pass amplifier of SHENGUANG Ⅱ facility results.

By using the Faraday effect in Nd:YAG and the rotation of polarization in a non plannar ring resonator, single frequency output from an all solid state out of plane Nd:YAG ring laser is demonstrated. The maximum single frequency output of 365 mW at 1064 nm has been achieved with slope efficiency of 36.2%, the intensity fluctuation is less than 2% and the frequency shift is less than 45 MHz in 1 minute. Single frequency output of 75 mW at 532 nm has been obtained by intracavity frequency doubling. The intensity fluctuation for 532 nm is less than 4%.

Based on the rate equatation, CCTS optical bistable laser is accurately analysed and calculated, the characteristic of its stable state is experimently studied and tested. We also found for the first time that when the laser output high state, another optical bistable and switch effect will occur. It is attributed to the self electro optical effect of the multirquantum well PIN detector. A new integratable bilogical functional net model device is indicated.

A self mode locked ring cavty Ti:sapphire laser is demonstrated. Self mode locked operation is achieved in both bidirection and unidirection with pulse durations as short as 36 fs and 32 fs, respectively. The laser performence is discussed in detail.

An ABCD matrix expression for propagation of both axial symmtrical and Gaussian beam through Kerr medium is derived based on the nonlinear Schrodinger equation. This expression is simpler than others and can be used to design resonators for Kerr lens mode locking. As one of the applications a type of resonators for Kerr lens mode locking is discussed.

An ultra sensitive imaging system was developed and used to obtain the ultra weak builuminescence image of a living Kunming mouse, and statistical analysis was used for studying photon frequency distribution. In this paper, for the first time we use X 2 ruler to calculate the signal photon and background photon distribution parameters for the image processing. It has been proved that this method is effective in processing the ultra weak bioluminescence images. The S/N ratio is increased and the image quality is improved.

A digitalized ultra sensitive fluorescence microscope has been developed, in which an intensifier CCD is used as high sensitive image detector with luminance gain of 41,000. It can detect ultra weak fluorescence image and decrease the concentration of fluorescence label and emitting light intensity in order to keep natural situation of the detected cell. This digitalized microscope can be used not only to obtain the fluorescence image, but also get the light luminance at every point of the image and the average light luminance of the whole image quantitatively. With this instrument, we have obtained: 1) The image of hypocrellin-A distribution in HeLa cell, it shows the HA is mainly absorbed by cell membrance; 2) The image of HeLa cell be oxidated by strong light after adding HA; 3) Images of HeLa cel being protected by three antioxidant reagent Vit. E, sodium ferulate (SF) and butylated hydroxytoluene (BHT), from which it has been shown that anti-oxidated effect of Vit E is the best; 4) The curve of absorbed quantity of HA in a HeLa cell with time versus culture time; 5) The curve of absorbed quantity of HA in Hela cell versus concentration of HA solution.

The population transfer of a four level system coupled with three lasers is investigated in terms fo dressed atom model, and two dressed states are found to be similar to the so called trapped state in three level system. The population trapping in the four level system is analyzed and an optical pumping method with high efficiency is proposed for pouplation transfer from both ground state and metastable state. The superiority of the method is demonstrated numerically when it is used in U isotopes separation.

Some experiments were demonstrated on bistability using acousto optic (A O) devices (1D and 2D) and a driver which can provide frequency feedback, and succeeded in implementing bistability by means of frequency feedback. The experiment results agree with the theoretical calculation.

Relation between chirp and stretching/compressing ratio is given at first. And by analyzing the variation of pulse width and chirp during amplification, the minimum pulse width after CPA is abstained. Comparison between theoretical and experimental result shows that the theory is quite validate.

The dynamic equations of the photorefractive two wave mixing (TWM), which accout on the beam fanning effect, are derived and solved by numerical method. The suppress effect of TWM upon the incident beam fanning in large signal is presented and the effect of the beam fanning on the output of the signal are discussed theoretically. Some relevent experimental investigation is conducted.

In this paper the focal shifts of paraxial converging spherical waves with non uniform amplitude are analysed, and the analytical expression of the focal shifts is derived. Based on the theory of hydrodynamics model of optics (HMO), it is pointed out that the focal shifts are attributed to the intrinsic movements of the light beams.

Two optical fiber sensors are suggested for simultaneous measurement of multiparameter incorporated in the elliptical core fibers. One is a dual technique fiber sensor utilizing polarimetric and two mode interference for measurement of four parameters. Another is a two mode interference multiparameter fiber sensor. The analyses of cross sensitivity and error are given, and the condition numbers of the sensitivity metrices is evaluated by using the theoretical model.

Experimental results of deep submicron lithography with a excimer laser are reported in this paper. With a free running KrF excimer laser, an illumination system including a light pipe uniformizer and a broadband catadioptric 1:1 projection lens with an aberration correcting planoparallel plate, the resolutions of 0.6 μm and 0.5 μm L/S patterns are produced on two resists respectively.

This paper reports the experemental study of phase transition properties of VO 2 films in irradiation of TEA CO 2 laser. The experemental results show that at biasing temperature 52 ℃, incident fluence of 150 mJ/cm 2 for TEA CO 2 laser phase transition can be occured from semiconductor state to metal state for our VO 2 films. Response time <50 ns, restoration time≈200 μs.

The phase generated carrier (PGC) modulation-demadulation scheme of the interferometric fiber-optic sensor is studied. The new bandwidth requirement of the scheme is analyzed, and stabilized analogic sensing signal is obtained by PGC detection scheme in the laboratory environment, which proves the paper's theoretical analysis.

Based on the new results of studying extraordinary rays′ behavior and the refractive index of the extraordinary wave in uniaxial crystal , an exact model of the optical path difference yielded by birefringent filters is set up. Then the versatile and precise formula for the filters is derived without the approximation Δn=n o-n e≤n o (or n e). The new model shows the correct position and dimension in each path while the filter is tuning. The formula is applicable not only to the filter made of the crystal with the optical axis parallel to the surface (FAPS) also to the one with the axis incline to the surface (FAIS). It is pointed out that the FAIS enables to tune laser wavelengths in a wider range than the FAPS. The origin of the wide range is interpreted as the variation in the index of the FAIS is larger while tuning the filter. With the help of the formula, a FAIS for tuning a Ti:sapphire laser is presented.

A kind of photo diode detector used in Tokamak visible light measurement was developed. This kind of detector characterized by its high quantum efficiency, good linearity, wide frequency and low noise has many advantages, such as small size, low cost and easy for use. It is satisfied to measure week visible light in Tokamak.

The performance of Cr 4+ :YAG as a passive Q-switch for Nd3+:YAG laser has been studied experimently. The single pulse energy of 145 mJ, pulse width of 30～40 ns and the efficency of 1% are obtained.

The validity of the equivalent refractive index for describing the external mixture of atmospheric aerosol particles was analyzed by scattering efficiencies, cross sections, and phase functions of monodispersions and polydispersions of the external mixture of two typical aerosol particles with their complex refractive indices of very high and very low imaginary parts. Results show that for monodispersions, the equivalence for the absorption efficiency and phase functions is poor; for polydispersions, the equivalence is stable but with quite large residuals. The retrieved size distribution will have a large bias if the equivalent refractive index is employed in light scattering techniques. It was recommended to use light scattering techniques simultaneously with other techniques to monitor the mixture property of aerosol particles.

In this paper, the random fluctuation characteristics of the atmospheric turbulence coherence length and the light beam propagation far field strehl ratio are analysed and their probability density functions are derived based on the characteristic function of random variable. The theoretical analysis is validated by the experimental results.

After preparing the large cross section single mode rib waveguide and it′s Y power splitter of GeSi alloy, this paper studies (1) FD BPM is used to simulate the light propagating in the splitter and the comparison between FFT BPM and FD BPM. (2) The simulation of λ =1.3 μm light propagating in the designed 1×4 splitter. Results show that compating to FFT BPM, FD BPM is easier to deal mathmatiocally and computing speed is faster and not very sensitive to the change of Δz . The simulation of 1×4 power splitter is succeddful. When the single-mode Gauss beam incidents into the splitter, the light propagated in the device according to requirement. At mid-way it splites into 2-beam and inot 4-beam finally.

In this paper we present an essentially analytic method for solving multilayer metallic optical waveguides using the asymptotic theory. The wave number is expanded into asymptotic series in terms of a small parameter. This method is exact and can approach any accuracy desired. However, the numerical results for four layer and five layer structures show that the second order solution is accurate enough. It is simple and has the same form of expressions for TE and TM mdes and different layer structures.

In the paper, the method for fabrication of diffractive microlens array using laser direct lithography system and reactive etching machine is described. The diffractive efficiency and the fabricating errors are analyzed. The microlens array has been used in a minature Shack Hartmann wavefront sensor.

This paper deals with a optical method of edge enhancement of the binary image using the step filter. Properly shifting the filter on the frequency region can improve the contrast and the contour acuity of the output image. It is profitable for edge detection.

A CW Nd3+:YAG laser of single frequency and single mode at 1.3188 μm is diveloped. The laser threshold, direction, stability, laser spectra and laser output power are measured. The results were analysised by optical theory.

The design of architecture energy conserving coatings with the metal double layers and the tripe layers is presented. A detailed discussion involves the design parameters as well as the transmittance and the reflectance properties. Uniformity of thicknesses of large area coatings is simulated by a computer and optimized distribution of evaporation sources is given. Experiments show that acceptable uniformity can be reached by using computer simulated distribution of evaporation sources. The measured spectral properties of such coating are presented.

In this paper, the five aperture shearing camera used for measuring second order derivatives of objects is presented. The pure second order derivatives of objects can be obtained by using the double whole field filtering technique.

Measurements have been made of He Ne laser transmission through suspensions of SiO 2 in silicone oil. When electrostatic fields were applied paralled to the laser path, transmission could be adjusted through selecting proper electrostatic field and suspension concentration. While electrostatic fields were applied perpendicular to the laser path, transmission declined quikly and then recovered slow, but no initial decline was observed for high concentration suspensions.

Fabrication of LiNbO 3 crystal waveguides implanted by He + ions is reported in this paper. The effective refractive index of the guided modes were measured before and after annealing. The refractive index profiles were calculated and proved to be in agreement with the damage profile and range profile.

The absorption spectrum and fluorescence spectrum of Tm:YAG crystals have been measured. The oscillator strength of absorption transitions have been calculated. According to the Judd Ofelt theory, the spectral strength parameters Ω 2= 0.5×10 -20 cm 2, Ω 4 =1.0×10 -20 cm 2, Ω 6 =0.4×10 -20 cm 2 of Tm 3+ have been fitted. Then the spectral parameters of Tm 3+ including spontaneous emission oscillator strength, transition probabilities, radative lifetime, fluorescent ratio and integral emission cross-section have been calculated. Pumped with 694.3 nm ruby laser, the laser pulse of 40 mJ at 2.01 μm was obtained.

The diffuse band originated from 21∑+u─x1∑+sub>gtransition was theoretically calculated and compared with the results of Luh′s, Milosevic′s and Gondal′s experiments. The results of the calculation are coincident with the experiments by Luh and Milosevic, and the interpretation that the diffuse band around 600 nm are from 21∑+u─x1∑+sub>gtransition can be rejected.

The diffuse band emission of K2 23ΠG-x3∑+utransition was experimentally studied with single photon excitation by a dye laser. The gain coefficient of 1.2% cm -1 has been measured.