This paper deals with the calculation of the additional loss and the additional extinction ratio caused by the alignment error in connection of two polarization maintaining fibers (PMF) using mode analysis method. The corresponding mathematial model and the calculated results are presented. The results are useful for the design of connecting, fusion splicing and coupling of PMFs.

According to the principle of coupling mode and the electromagnetic fields in fiber core and cladding with concentric ellipticity expressed by Mathieu functions, the analytical function formula is given in this paper for coupling coefficient of even mode in ground mode field under proper approximation conditions. The resluts of the eccentricity against coupling coefficient and the half major axis against coupling coefficient are obtained at cutoff frequency.

A laser field that contains both additive and multiplicative noise are analysed based on a full saturation laser model. The numerical solution of intensity correlation time T c as well as the exact formulas of effective eigenvalue λ eff are calculated. Compared with the experimental measurements, excellent agreement is obtained for the full saturation laser theory, while relatively large errors occured in the third order laser theory and the measured data. By best fitting the experimental data of both Tc and λeff with the full saturation laser model, the cavity decay rate K of the laser sytstem can be determined, therefore it provides a theoretical evidence for measuring K.

In this paper, we present a novel method for locating of a moving object. According to its Fourier spectrum. This method has the advantages of having a high locating precision and ignoring the change in pose of the moving object. The principles are introduced, the computer simulation and the experimental demonstration are given, the practicality of this method is discussed.

Real time image subtraction and addition of two image bearing phase conjugate waves are demonstrated by using a novel mutually pumped phase conjugator induced by self pumped phase conjugate reflection, for either a complete or an edge enhancement phase conjugate output of the image carrying on the signal. A 16° cut KNSBN crystal is used. The resolution of phase conjugate output image is as high as 50 pl/mm.

We report for the first time the laser operation of a tunable Ti:sapphire laser pumped by the third-order Raman laser of the XeCl/H2 system at 499 nm with 60 ns duration. The slope efficiency is 59% for this laser operation, producing pulses of 20 ns duration. The highest energy conversion efficiency is 42% with an output energy of 1.2 mJ. The tuning range for a single set of cavity mirrors is 680~834 nm and is limited by the mirror reflectivity.

This paper described a dye laser with zig zag cavity pumped symmetrically from two sides by 308 nm XeCl excimer laser.Improvment of the output beam was investigated and the experiments show that the quality of the output beam by using symmetrical pump from two sides is better than that by using ordinarily transversal pump. For dye coumarin 460 dissolved in methanol with 2×10 -3 mol/l concentration, energy transference of η =11.7% was obtained at the wavelength of 460 nm.

The gain ripple characteristics in traveling wave semiconductor optical amplifiers (TW SOAs) are studied in detail. A uniform carrier distribution along the cavity length in a TW SOA is usually assumed in many previous papers. However the theoretical model proposed in this paper accounts for the spatial dependence of the carrier density. Gain ripple value changes with the residual facet reflectivity, spontaneous emission factor, and incident optical power, etc. Good agreement was obtained between the calculated data and the experimental results.

The plasma compression and shock generation along the light pressure gradient are investigated in an ultra intense laser irradiated plasma, where the light pressure is dominated over thermal pressure. The threshold for directly driven shock and scale laws for hydrodynamic parameters are calculated by the pistol model.

Experiments and model calculation show that no soft threshold presented in a frequency shifted feedback Nd∶YLF laser, while the system with injection seeding will possess a soft threshold. It was found experimently that this behaviour becomes apparent with increasing the power of injection seeding.

A three-dimensional program of amplified spontaneous emission (ASE) for high power KrF laser amplifiers with a cylindrical symmetry and small aspect ratio is developed. The analysis using the present program indicates that the optimum scaling of the transverse and the longitudinal gain length product should be smaller than 3 and 10, respectively. Characteristics of the experimental device 100 J KrF laser and a three staged amplifier system are calculated.

Optical damage of several kinds of infrared window materials with 1.06 μm and 0.5106 μm high repetitive laser pulses irradiation has been studied. Mechannism of laser damage is considered as laser induced defect development accumulation process. We first recommend a concept of an absorber and establish a simple model to verify this process. To increase resistance of infrared window materials to the repetitive laser pulses damage, a laser pre irradiation technique is used.

A relative calibration has been completed for SIOFM 5FW X ray film by using a TLAP crystal as dispersion element, spot focused laser produced Cu plasma as X ray source and net foil as intensity attenuator for obtaining different exposure.

A new kind of fiber optic sensor is proposed, which can remove the polarization induced fading (PIF) in conventional low birefringe single mode optical fiber. By adding high frequency modulation to the state of polarization in one arm of the interferometer, the effect of PIF is elimineted at the visibility of 0.707.

The relation between the chirp in phase of soliton pulse and soliton propagation is discussed in this paper. It is shown with numberical results that the chirp always changes sign whenever soliton pulse alternates between narrowing and broadening. The critical length of soliton propagation (with which the lumped amplifiers are separated) can be determined by means of the chirp, and the effect from this method is better than that from pulse width recovery scheme.

The equations of the pulse width and frequency shift of femtosecond optical soliton transmission in fiber with band limited distributed gain are derived by perturbative theory. The equations have stable solution and the analytic expressions of pulse width and frequency shift are obtained while solitons propagate stably.

An experimental set up of photon counting real time image acquisition system is introduced. Wherein a photon image head (an image intensifier with high radiant emittance gain) is coupled with a high frame rate CCD camera by a super powerful relay lens. The restrictions on luminous emmitance of object are analysed for single photon imaging mode. The methods of determining readout noisethe major comprehensive specification of system for multiphoton imaging mode is introduced. The application examples of system in adaptive optics wavefront sensor operated with a faint object, and in experimental study on the photon noise distribution, the optical wave-particle duality are presented.

By virtue of a numerical method of truncating an infinite matrix to finite order, we have investigated the squeezing properties of atom in the Jaynes Cummings (J-C) model. Numerical results have shown that dipole squeezing and quantum collapse revial phenomena can be observed in the cases rather close to integrable limits, while these features disappear in the cases far from these limits.

The RF excited packed waveguide CO2 laser have been studied experimentally. When the dimensions of two packed waveguides both are 1×14.5×200 mm3, the maximum output power of 75 W and the maximum efficiency of 10.8% are obtain. This simple structure laser has a single peak beam output at the far field.

Characteristics of phase modulation of a nematic liquid crystal is studied. A new phase shifting shearing ESPI system which uses parallel aligned liquid crystal as a phase modulator is deceloped. This method lincreases the mearsuring accuracy of shearing ESPI by combining phase shifting technology with shearing ESPI. The phase modulation is simple. The correlation fringe method is used for phase calculation. Satisfactory results are acquired in the experiments on deformation measurement.

Porous silicon/laser dye composite was obtained by efficiently inserting laser dye into porous silicon. The composite shows luminescent property of both the porous silicon and the laser dye when inserting trace dye. Increasing the insert of dye molecules, luminescence of the composite increases, the rise time becomes faster, the pulse width of the luminescence narrows, and the composite shows mainly the luminescent property of laser dye. The luminescence peak position of the composite shifts clearly to the blue compared to that of the same dye in alcohol solution.

A ultralow speed measurement system and the experimental results are reported. Its optical system is a four beam two focus differential laser Doppler velocimetry system (LDV) and the signal processing system uses a dynamic phasemeter. The measurement range can be from 1 nm/s to 300 mm/s.

The near infrared emission in the spectral region of 0.98-1.04 μm with peak around 1.0 μm has been observed by excitation of high lying state of Na 2 with UV dye laser, and the emission is attributed to the 2 3Π u →1 3Σ + g transition in Na 2.

The effects of K + ion on F + 2 like color center formation and opical properties in OH- doped NaCl crystal are studied. The experiments show that K+ ion suppresses the formation of F + 2 like centers and makes their absorption and emmission spectra broaden and red shift. With more dopants, the effect is stronger. The results suggested a correction on those given by C. R. Pollock group. As the FWHM of emission is increasing with K+ dopants, it is possible to prepare F+2 like centers in complex host Na1-xKxCl()H-) crystal as a laser medium.

The multilayer grating combined structure can be obtained by depositing the soft X ray multilayer on the laminar grating. In this paper, we report the diffraction performance of the multilayer grating under the irradiation of Cu K α X ray at low angle. Analysing with X ray kinematics theory we obtained two diffraction conditions, corresponding to the grating equation and Bragg law respectively. The efficiencies of grating were found to be modulated by the multilayer reflection. The values both of experiment and theory of diffraction peak positions and intensities are compared and analyzed under three different scan methods such as specular reflection scan, sample scan and detector scan. The results show that they are coincided well.

A cobalt phthalocyanine (CoPc) thin film was obtained by vacuum deposition on a single crystal silicon. The ellipsometric spectra of CoPc thin film have been investigated on a scanning ellipsometer with the analyser and polarizer rotate synchronously. The spectrum is explained with its energy levels.