A novel method for propagating light-knife by the reflection of Gaussian laser beam at a cylinder is put forward and the formula to appraise the geometry parameters of light knife is also derived. The experimental results show that the light-knife generated by using this method has less width variety, higher contrast and large depth of field. It could be used as a line structure light in active 3D profile measuring system.

A Rayleigh scattering lidar is presented for temperature observation in the mid and upper stratosphere, both principle and process of data analysis are described. Temperature profiles obtained by lidar show the coincident distribution with the NOAA/NMC and MSISE-90 model over the altitudes of 30 to 40 km. Generally, temperature biases between lidar and NOAA/NMC or MSISE-90 model are less than 3 K from 30 km to 40 km altitude, not larger than 6 K at the lower altitudes probably due to the influences of aerosol.

The quantum wavepacketinterference in rare earth ions is observed with dual-channel correlation spectroscopictechnique using a femtosecond laser. The measured dephasing time of Eu3+ ionsin Y2O3:Eu3+ at room temperature is longer than 3 picoseconds,and the quantum wavepacket interference is recorded in the free-induction decay process ofEu3+ ions. Some systematic errors in the experiments are discussed and thesolutions are suggested. Experimental skills are reported.

Chemically cleaving-etch method was presented to form relief modulation in gelatin based on the analysis on the cleavage of protein. Thank to the much fewer number of cleavage site for chemical cleavage than that for enzyme, chemical cleavage method was of higher etching resolution and better profile fidelity. The predication was proved to be right and experiments showed that relief modulation resolution was got to 500 lines/mm spatial frequency, which was much higher than enzyme method. With the projection exposure system, a micro-prism array with 30 μm wide and 0.8 μm high cell dimension was fabricated using the chemically cleaving-etch method.

In order to fabricate sol-gel microoptical elements, characteristics for dip-coating, such as the thickness of the films and the their uniformity, are investigated. Under the low withdrawal rate (<20 cm/min), thickness is linearly related to the square root of the rate. At the high rate (>20 cm/min), thickness increases slowly with the rate, deviating from above relation. An analysis of the dip-coating process shows volatilization of solvent plays a role in characteristics of the films.

In this paper, the factors of affecting thermal fixing efficiency, and lifetimes of fixed gratings under both illumination and dark conditions are analyzed theoretically. The characteristics of fixed reflection gratings in Fe:LiNbO3 and Ce:Fe:LiNbO3 crystals recorded using red wavelength have been extensively studied. The experimental results show that development of ionic gratings in crystals with high concentration and deep reduction is not available. For lightly doped unreduced crystals, the thermal fixing efficiency up to 50% has been achieved. The lifetime of the ionic grating under continuous illumination is up to 300 hours, which is one hundred times more than that of the electronic grating. The dark storage time can reach 4 months, ten times more than the lifetime of the electronic grating. The experimental results demonstrate that the conditions required for increasing thermal-fixing efficiency will decrease the lifetime of ionic gratings, as predicted by theory.

Four lithium niobatecrystals doped with Cu:Ce, Mn:Cu:Ce, Mn:Fe, and Mn:Fe:Mg, which are processed under two different oxidation/reductionconditions, have been studied experimentally for non-volatile holographic storage withultraviolet and red light. The non-volatile holographic storage in LiNbO3:Cu:Ce and LiNbO3:Cu:Ce:Mn crystals is realized. The results show that higher oxidizedcrystals may realize non-volatile holographic storage. The persistent diffractionefficiency of non-volatile holographic storage of LiNbO3:Cu:Ce crystal is the largest on the premise of high signal-to-noise.

Monte-Carlo simulationsfor research on the influence of the inhomogeneous object in the medium on timecharacteristics of ultrashort pulse light propagation are presented. In frequency domain,the inflence of the position and size on imaging is analyzed by use of the difference ofamplitude or phase. The results show that the detection by the phase difference is moresensitive than that by the amplitude difference, and the higher frequency of detection,the more sensitivity of imaging. The geometric structure of light source and object hasthe influence on the imaging, the collinear structure has the best imaging effectiveness,the influence on imaging from changes of lateral position of the object is more seriousthan from changes of the longitudinal position of the object. The size of the object alsoinfluences imaging, the larger size, the better imaging. The resolution of imaging systemis determined by many factors, such as the SNR of detection, the geometric structure andthe optical properties of the object and so on.

A way to manufacture kinoform of actual object is proposed. A kinoform is given by two steps―inputting optical hologram in computer by scanning and then analyzing its information of object wave.

In this paper, the characteristics of new gene variant (BRM1B) and its behavior of the writing, reading and erasing of the information in a bacteriorhodopsin film are investigated. A system of three-wavelength EDRAW (Erase Direct Read After Write) was constructed. Optical data was written into BR film with 670 nm laser based on the B to P photochemistry reaction. Then the information was erased with 490 nm laser based on the reconversion of the photoproduct state P. The resulting data could be read out with 594 nm laser based on the differential absorption of B and P states.

The microstructure characteristics and microsegregation of DD2 single crystal have been studied under ultra-high temperature gradient and rapid solidification conditions by laser rapid remelting. The experimental results show that the microstructure has been greatly refined after laser rapid remelting, interdendritic precipitation phases remarkably suppressed and the microsegregation substantially improved.

A new technique forsurface modification of polymer fibers is introduced by irradiating with UV excimer laser,this technique can be used to modify the chemical and physical properties of fiberssurface. Under certain conditions the irradiation of polymer fibers induced acharacteristic morphology on the polymer fiber surface. The original smooth surface ofpolymer fibers changes its morphology to a rather regular roll-like structureperpendicular to the fiber axis after this treatment. The dependence of characteristicsurface data on laser fluency and pulse number is studied. The mechanism for formationperiodic surface is also discussed.

The computer simulationand experimental results of diode pumped high-repetition-rate Nd:YAG laser are reported. According to the calculations andthe experimental results, the parameters of components were determined. By using KD*Pcrystal for E-O Q-switching, an 8 ns Q-switched laser pulse output of 35 mJ was obtainedunder pulse repetition rate of 200 Hz. By using KTP crystal for SHG, the double frequencylaser output of 20 mJ at 7 ns pulse width was realized. Furthermore, the design principlesand structures of the laser are also introduced.

A novel scheme ofdual-frequency Nd:YAGlaser is proposed and demonstrated. The resonant cavity of the laser contains a piece ofversatile element: crystal-quartz-made birefringent Fabry-Perot etalon, serving as both aselector and a splitter of laser axial-modes. Because of the intra-cavity birefringence,each longitudinal mode is split into two linearly and orthogonally polarized components,that is, ordinary mode (o-mode) and extra-ordinary mode (e-mode). Meanwhile due to thesame reason, the unique transmission maximum of the etalon within the overall lasingbandwidth of the Nd:YAGlaser is also split into two transmission maxima, namely, ordinary light transmissionmaximum (o-peak) and extra-ordinary light transmission maximum (e-peak). Simultaneousoperation of the two axial modes can be obtained, by making an o-mode coincide with thecentral position of the o-peak, and an e-mode with that of the e-peak. A piece ofbirefringent Fabry-Perot etalon, with a geometrical thickness of 645 micrometers and acut-angle of ten degrees between the quartz crystalline axis and the normal of itssurfaces, has been designed and fabricated. A frequency-difference of approximately twogigahertz has been obtained experimentally, when the above birefringent etalon beingplaced in a 40-millimeter-long cavity of the LD pumped Nd:YAG laser.

In this paper, a high-efficiency harmonic generation system capable of two beams which have a certain time interval and different wavelengths from two frequency doubling Cr:LiSAF laser passing through a BBO crystal at phase matching angles has been developed. The two beams are combined to obtain a dual-pulse and dual-wavelength FHG beam of Cr:LiSAF laser system.

Intracavity-doubled 670nm Nd:YAlO3/LBOlaser was reported. The parameters of the cavity are calculated. Based on the analysis,the suitable cavity parameters are determined and the 670 nm laser of 1.2 W is got underthe pumping power of 1664 W, the transition efficiency of fundamental wave to harmonicwave is about 1.6%.

A detail description of LD pumped intracavity-doubling ring laser is presented. The ring laser is pumped by an 808 nm LD which has a fiber-tail with maxim output of 810 mW. Using YVO4 and KTP as the laser crystal and doubling crystal, a maxim of 2 mW 532 nm TEM00 mode green laser is achieved. Laser frequency can be tuned about 12 GHz by moving one of the cavity mirror with PZT.

An external cavity semiconductor laser configuration, which employs fiber grating as feedback is reported in this paper. The fiber grating is fabricated by UV light exposure, with reflectivity of 50%. At injection current of 50 mA, output is over 1 mW and the MSR is 42 dB. The laser wavelength is tuned by applying strain along the fiber grating and by heating the fiber grating. With the applying-strain method, the tuning range of 2 nm is obtained.

In this paper, the Yb3+-dopedring cavity fiber laser is compared with the F-P cavity fiber laser which were both pumpedby LD with fiber pigtail. It is found that the lasing wavelength will be changed when thestructure of cavity is varied. And it is also found that the Yb3+-doped ringcavity fiber laser have lower cavity loss and pump threshold, while F-P cavity fiber laserhas narrower FWHM.

This paper reports an analysis of problem about impedance match of pseudospark e-beam source of free electron laser and the experiment results on compact device without pulse transmission line. The e-beam of 4.3 kA current under 255 kV discharge voltage is obtained and the impedance curve of pseudospark discharge chamber filled with nitrogen at 15 Pa is given.

In this paper, a kind ofmicrowave-discharge pumped cw atomic mercury laser is introduced and demonstrated. In thisexperiment the laser is put in a microwave-guide, laser light is produced by means ofmicrowave discharge. Whole dielectric medium, inner-cavity style, and co-axial structureare employed. 80 W microwave power is input in the microwave-guide, 30 W power is absorbedby the mercury medium. Laser cavity consists of 2 m spherical radius mirrors withreflectance of 99.9%. Laser wavelength is 546.1 nm and its maximal power output is 0.1 mW.Light spot size is 3 mm with several transverse modes.

Under the condition of free attenuation of shock wave, based on the momentum, energy and mass conservation, the formulae of calculating laser plasma shock wave front temperature, pressure, density and velocity have been given. Only if the shock wave velocity is 1.5 times greater than the local sound speed, the calculation results agree well with experiments. Otherwise some new transition characteristics arise and the shock wave model is no longer applicable.

A novel scheme for remote supervision of in-line EDFA and fault-location in EDFA cascaded system based on subcarrier modulation is theoretically proposed and experimentally demonstrated. In the scheme, FSK-FDM technique is used in subcarrier modulation, and the EDFA’s supervisory information is transmitted by optical intensity modulation. In this 10 Gbit/s WDM transmission experiments, the system power penalty was 0.16 dB and 0.86 dB, while the subcarrier modulation degree was 3% and 15% respectively. With the technique of phase-lock, demodulation of supervisory information was realized while the modulation degree was 3%. The conclusion comes that this scheme can be applied in a long-haul WDM transmission system with five EDFAs cascaded.

Based on analyzing of bit-error performance, parameters optimization for XGM wavelength conversion in semiconductor-optical amplifiers (SOA), which was used in communication system, is presented in this paper. Segmented model for SOA, transferring matrix method (TMM) and average spontaneous emission power are exploited in the theoretical analysis. Carrier consumption due to amplified spontaneous emission is introduced in the carrier rate equation. Results show that there exist optimal values of probe power, average pump power, conversion span and length of active cavity for special condition. It is also shown that small waveguide internal loss is helpful to achieve good bit-error performance.

The differences between forward and backward ASE in ytterbium-doped monomode silica fiber are described. The changes in ASE spectral shapes under different pump power, different activated fiber length and different pump wavelength are investigated. The results could be important for the design of YDF devices such as superfluorescent laser sources, tunable lasers and traveling-wave amplifier.

In this paper, the pulselaser waveform output from RF excited waveguide CO2 laser is fitted by Gaussfunction. The waveform of pulse laser heterodyne and its frequency spectrum of Fouriertransform are studied in theory and experiment. The experimental results are consistentwith that of theory.