A self-integrating coil measurement of intense current in a successfully-operated pseudospark electron beam source characteristic of high power,intense current density,low emittance, and high brightness is introduced.The practical design and calibration ways are given. Experiments show that this coil behaves very well in the case of intense current;the quality of the pseudospark electron beam is much better than that of the cold cathode one.

Direct determination of fluorescence quantum yield in dilute dye solution by a laser photothermal deflection method is rePOrted.An experimental verification of the method is carried out for Rhodamine 6G in methanol and advantages of the method over different methods are discussed.

In this paper,the principle of CGH (computer-generated-hologram) phase detecting interferometry is briefly discussed.A new absolute measuring method with CGH for testing high precision aspheric surfaces is presented.The measuring accuracy can be up to λ/50.

A line focus system with continuously variable aspect ratio for uniformillumination is developed.It is composed of two cylindrical lenses and a segmented wedgearray. After the line length varied,the width,intensity distribution along the line length,and the target position are still unchanged.The theoretical analysis agrees with experimcmtalresults.

We use a new optical element──fibre-bundle beam translator in place of largeaperture lens and slits to make rainbow hologum for raising the viewing angle.This paperinttoduces the principle of the beam translator and also gives the experimental results.

This paper reports studies of the corrosions,fatigues,and fracture characteristicsof cobalt-base cladded coating on 2Cr13 steel substrates,performed at 50 Hz in 3.5% NaClsolution(PH=7).The corrosion fatigue lifetime curve was determined. The results showthat almost all corrosion fatigue cracks of laser cladded specimens derive from pits on thesurface of 2Cr13 steel substrates. Cobalt-base laser cladding coatings on the specimens gavea greatly increased corrosion fatigue lifetime comPared with 2Cr13 steel specimens becuase the initiation of corrosion fatigue cracks is restrained by the laser cladded coating. From the results, t may open up a new way to the application of laser cladding technology.

The transient behaviors are studied by means of a numerical rate equation treatment of a short cavity dye laser in which a saturable absorber DODCI is mixed with a gum medium Rh6G. Single longitudinal mode,ultrashor dye laser pulse.trains(both picosecond and femtosecond)can be generated using this methocl,and agree well with the experimental results reported.

Frequency-stabilized and frequency-doubled ring Nd:YAP lasers with a 6-mirror cavity or a 4-mirror cavity have been demonstrated.The designed lasers satisfy conditions both of thermal insensitivity and of optimum frequency-doubling. The secondharmonic outpllt POwers up to 800 mW and 580 mW with the intensity fluctuations less than ±2. 5% and±2% as well as the long-term frequency stabilities better than±1.9 MHz and±1 MHz have been obtained respectively for the 6-mirror cavity with an input electric power of 1.2 kW.

A novel heater with a metal pipe was designed which is used encircling the discharge tube of a CuBr laser,resulting in homogeneous distribution of axial temperature.The Power of the CuBr laser with flowing buffer gas has been increased three times than the previous prototype of 9W average power and an efficiency of 1%.The maximum average POwer was 10.6 W.

The calculation program of ASE for a large KrF amplifier with full-3D and quasi-3D code is designed.Comparison between two models is Performed.The ASE and extraction efficiency for a series of aspect ratio, gain to loss ratio and input intensity are calculated. With a 100 J KrF laser made in China as an amplifier,the noise to signal ratio is about 5% under 0.1 saturation inpllt intensity. Our full- 3D and quasi-3D codes are suited to the design of KrF lasers.

The characteristics of a LD pumped highly efficient Nd:YVO4 laser were presented. The output power of 230 mW with an optical conversion efficiency of 45% has been obtained.29.8 mW of green fundamental spatial mace light have been generated with a"light to light"conversion efficiency of 12.4% when the input pump power was 240 mW.Data are also presented for the spectral variation of the output with input pump POwer.We have observed an average laser wavelength variation of 1.05×10-3 nm/mW versus pump power.Using a synchronism-search compensation frequency-stabilized system and an electrooptic switch technique to the frequency-doubled pulsed ring Nd:YAG laser,we have obtained a frequency-stabilized and frequency-doubled laser at 532 nm,with a pulse width of 100μs,peak power of more than 100 W,and frequency stability of less than 10 MHz,while the intensity relaxation oscillation was eliminated.

The structural design with the largest net galn is presenteti for commonly-used InGaAsP separate-confinement-heterostruc (SCH) strained quantum-well lasers.The best wavelength and width of SCH layer are 1.24 μm and 1 00 nm for 1.55 μm unstrained single quantum-sell lasers.When compressive strain is introduced into the active layer,the best wavelength of SCH layer will be shorter because of the strain-induced reduction of state density and the enhancement of differential gain in quantum-well lasers.

The operation behaviour in a 3.39μm He-Ne laser of single-longitudinal-mode and multitransverse-mode has been studied. Ruelle-Takens rout and chaotic window have been observed by tuning the system parameters.The experimel tal results have been discussed with the aid of a simple theoretical model.

A novel vertical-cavity surface-emitting laser with grading DBR is reported in this paper.The structure is obtained by twice deep H+ implantations which use a crossed tungsten wire as the implantation mask. The fabrication process is the simplest ever reported in vertical-cavity surface-emitting lasers fabrications.In the primary experiment,the lasing wavelength of 871 nm,the lowest threshold current of 18 mA and the largest output power of 2 mW are obtained under pulse condition at room temperature using a current source with a 10 μs pulse-width and 100 μs cycle. The series resistances of the device are 100～200 Ω.

Time-resolved emission spectrum from laser-produced plasmas by 1.06μm, 10ns laser pulse's irradiation on silicon target surface in air at a flux of 9.3×109 W/cm2 isrecorded and analyzed between 200 and 880 nm. The ignition time of the plasma isestimated. The expansion velocity of Si atoms in the plasma is measured.A mechanism ofthe N+ ion formation in the plasma is proposed to explain the appearance of N+ ions observedin the plasma. It was found by means of measuring the variation of the FWHM of Plasma's the emission line at different delay time that the electron density in the plasma decreases approximatively as an exponential of exp(-t1/2).

Two-Color Laser-Induced-Grating Spectroscopy(TC-LIGS)is a newlydeveloped laser spectroscopic technique. This scheme offers the advantages of zerobackground detection,high special resolution and easy spectral edgnment. The secondharmonic output(532 nm)of a Nd:YAG laser is split into two pump beams of nearly equalintensity. These beams intersect at an angle of 2.73 degree and are directed into theIc sample cell. The interference of these beams preduces a sinusoidal distribution of an excited-state laser induced population grating and a ground state laser induced depletion grating in the iodine molecules. A narrow bandwidth dye laser is used as probe beam and directed to the laser induced gratings. The spectroscopic signal is collected along the direction of Bragg diffraction. By scanning the probe laser wavelength, 129 TC-LIG lines coupled between B and X states of iodine molecules are obtained in the 555.9~570.6 nm, 576.3~587.2 nm and 605.0~605.6 nm regions.

The interaction process of a high-power laser and a PIN junction optoelectronicdiode has been studied theoretically and experimentally.It has been put forward that thethermal effect of the laSer beam and the eroding and washing effect induced when the laserplasmas expend out result in the damage of the silicon photodiode.The thermal distributionand an expression of the maximum temperature have been obtained or the first time whenthe Q -switched Nd:YAG laser irradiates upon the PIN junction optoelectronic diode.

Ruthenate is a typical complex transition medal oxides of ABO3 type,whichpossesses metallic conductivity. Its film can be used as electrode material in integratedferroelectric devices,etc.In this context,the perovskitic features and conductingmechanisms in BaRuO3 crystal have been reviewed or analyzed.Perovskite BaRuO3 thinfilms of low resistivity (resistivity ranges from 10 -2 10 -3Ω.cm at room temperature)with(110)- orientation have successfully been prepared on Si(100) substrate by ArF excimer pulsed laser deposition (PLD) accompanied with subsequent annealing. Both Auger electron spectroscopy (AES) and Rutherford backscattering spectroscopy (RBS) showed that the film was pure and with good compositional homogeneity while there formed an intermediate diffusion layer between BaRuO3 and Si-substrate.

From the following two aspects:speeding up the heat copductance and reducingthe optical absorption,we in this paper,propose a detailed means to improve the laserresistivjty of aluminum mirrors and Si windows by depositing dielectric films.In the laserinduced damage test of suing a 1.06μm infrared laser and a copper-vapor laser,the damagethresholds of samples that are being protected all have been improved,which in turn verifiesthe rationality of our protecting means.The feasibility of the method is discussed.