Using the numerical solution of the full Maxwell-Bloch equations without the slowly varying envelope approximation and the rotating-wave approximation, propagation behavior of few-cycle laser pulse in a dense ladder-type three-level atomic medium is investigated and it is compared with the case in the corresponding dilute medium. It is found that, in the propagation process, time evolution of the pulse in the dense medium is obviously different from that in the dilute medium, and the difference will become more evident with increasing of the initial pulse area. When the initial pulse area is smaller, in the propagating process, the pulse shape in the dilute medium just have a small change; the pulse shape in the dense medium has considerable variation but the pulse splitting doesn't occur. When the initial pulse area is larger enough, for the dense medium case, the pulse splits into sub-pulses with different numbers and shapes at different propagation distances; while for the dilute medium case, variation of the pulse shape is still smaller in propagation process. The cause producing above difference is from two effects in the dense medium: the effect of the local-field correction (LFC) from the near dipole-dipole interaction and effect of stronger polarization field than that in the dilute medium. In which the effect of stronger polarization field plays a main role, but the role of LFC also cannot be neglected，and the stronger polarization field is due to the atomic density increasing.

Based on femtosecond laser inscription technology,a novel method for femtosecond laser micromachining system is proposed to fabricate a microfiber Fabry-Perot (F-P) cavity on the fiber end surface.This technique can solve the parallelism problem of the traditional fiber F-P sensors inscribed by femtosecond laser.The F-P interferometric sensor made by the proposed technique shows over 20 dB fringe visibility.This technique is parameter-controllable and easy to implement.It is a promising candidate of strain measurement in the case of extreme temperature circumstances.

An all solid-state continuous-wave yellow laser at 571.6 nm is reported.The yellow laser is from two Nd∶YAG line of 1 444 nm and 946 nm being a non-linear sum frequency,which correspond to energy levels in their respective crystal transition for 4F3/2-4I15/2 and 4F3/2-4I9/2,respectively.The yellow laser at 571.6 nm is obtained by using a doubly folded-cavity,type-II critical phase matching RTP crystal intra-cavity sum frequency mixing by 1 444 nm and 946 nm.When injected into two Nd∶YAG crystal for the pump power 25 W and 14.8 W,respectively,yellow laser at 571.6 nm of 562 mW is obtained.The power stability in 4 h is better than ±2.9%.

Dual-wavelength laser at 532 nm and 660 nm are covert from fundamental laser generated at 1 064 nm and 1 319 nm by single Nd∶YAG crystal rod.On the basis of 1 064 nm and 1 319 nm dual-wavelength laser acquirsition,the second harmonic wave at 532 nm and 660 nm can be achieved by using non-linear frequency conversion technology.The output power of 1 064 nm and 1 319 nm laser are 30.5 W and 8.78 W simultaneously，35.6 W and 11.2 W respectively.The output power of 532 nm and 660 nm laser are 5.34 W and 1.353 W at 10.5 kHz and 20.5 kHz simultaneously,6.72 W and 1.90 W respectively.The frequency-doubling conversion efficiency are 17.5% and 15.4% in the two condition mentioned above.The instability is less than 2%.

A novel white organic light-emitting device (WOLED) using a strategy of exciting organic/inorganic color conversion film with a blue organic light-emitting diode (OLED) is reported.The luminescent layer of the blue OLED is prepared by using of CBP host blended with a blue highly fluorescent dye N-BDAVBi.The organic/inorganic color conversion film is prepared by dispersing a mixture of red pigment VQ-D25 and YAG phosphor in PMMA.A novel WOLED with the high color stability by optimizing the thickness and fluorescent pigment concentration of the color conversion film are achieved.When the driving voltage varied between 6 V to 14 V,the color coordinates varied slightly from (0.354,0.304) to (0.357,0.312) and the maximum current efficiency is about 5.8 cd/A(4.35 mA/cm2),the maximum brightness is 16 800 cd/m2 at the operating voltage of 14 V.

Digital Micromirror Device (DMD) is employed as spatial light modulator to construct a digital maskless lithography system,which can be used to fabricate micro-nano photonic device conveniently.The imaging process of the periodic structure in the coherence light is analyzed.According to the numerical simulation and experimental result,the imaging process should be explained by the principle of Abbe′s imaging.With this system,2D periodic structure with the period of 900 nm is fabricated but defect is introduced.So DMD is a practical tool to fabricate submicron-sized pattern.

A realization of 3D-mouse is proposed.By the principle of stereo vision,the method based on autostereoscopic Display can make the common mouse point to any location at different depths in three-dimensional space which can be perceived by the viewers.And,a method of calculating the real position’s depth is also proposed and is verified experimentally.Theoretical analysis and experiment results show that the method of the realizing 3D-mouse and calculating the real position’s depth can make the autostereoscopic display be introduced into the digital photogrammetric system.

Polymer Mach-Zehnder thermo-optic switch is fabricated using traditional semiconductor technology.The surface of waveguide is observed by a scanning electron microscopy,and the output near-field spot is displayed on the infrared camera.At a 1 550 nm optical communication wavelength,the output spectrum is shown.The extinction ratio of the switch is －15 dB and the driving power is 16 mW.The switching property of the device is tested with DC bias.The rise time and the fall time of the switch are 1.2 ms and 0.8 ms.

The sapphire optic fiber thermometer for high temperature is described.The sapphire optic fiber is suitable for high temperature measurement because of its wonderful high temperature physical and chemical performance,which can be used for radiation optic fiber temperature sensors.A sapphire fiber thermal probe with Cr3+ion-doped end is grown by using the laser heated pedestal growth method.A laser is used to heat a small pedestal,so that fluorescence-temperature-responsing materials like a small ruby crystal optic-fiber will grow on the top of the sapphire optic-fiber,which can be made into a compact-structure,high-temperature and stable-function sensor head.Though the fluorescence life measurement,the corresponding temperature can be measured.According to the surface temperature,the inner temperature can be obtained by the temperature field.It can be used in measuring the steel fluid of the tundish in continuous cast steel machines.Experimental system of the thermometer and the preliminary experimental result are presented.The experiment results shows that it can realize non-touched measurement and has high precision.

A MEMS-based pitch-tunable grating with continuously variable pitch is proposed.The grating is electrostatic comb actuated.With the change of the voltage,the pitch and the diffraction angle of specific order are also changed simultaneously.In order to supervise the change of diffraction angle,an experimental measurement system is designed and established,the diffraction angle′s variability is obtained by image processing.The measured results agree with the theoretical calculation very well.The error has resulted from image processing and structure machining technics error.The experimental results testify about the tuning range of pitch(5%) adequately.This work lays a good foundation for our future research in micro spectrometer and optical communication,and provides valuable technical references.

The transmission performance of the carrier signal distribution system based on double sideband-carrier suppression modulation is studied.The principle of double sideband-carrier suppression modulation,the expression of the output power at double frequency and the influcence factors of phase noise degradation induced by the system are analyzed and verified by measuring the power and phase noise of the input carrier signal and the output double frequency signal.It is shown that the output power at double frequency is -5.7 dBm,the close-to-carrier phase noise of the output double frequency signal is inherently degraded by 6 dB and the far-from-carrier phase noise is degraded by 21 dB.

A dark notch is generated by using an amplitude mark to cross partially spatially incoherent light beam.The notch is imaged onto the input face of the crystal.The full width at half maximum of notch is 16.75 μm.Power of input beam is 400 μW.Based on the bulk photovoltaic effect,a pair of Y-junction dark photovoltaic solitons is written with partially spatially incoherent light beam when the background illumination is absent.The experimental result demonstrates that Y-junction dark photovoltaic solitons can be written in LiNbO3:Fe crystal without background illumination.

The effect of the electron-phonon interaction on the Optical Kerr effect is investigated theoretically for electrons confined in a core-shell quantum dot.The interactions of electrons with different phonon modes in the core-shell system,including the confined longitudinal optical (LO) and the interface optical (IO) phonon modes,are investigated.It carried a detailed calculation of Optical Kerr effect on a ZnS/CdSe core-shell quantum dot as a function of pump photon energy with different incident photon energy and under different sizes.The results reveal that the polaron effects are quite important especially around the peak value of the third-order susceptibility.

A symmetric five-layer slab waveguide with a core of left-handed material and surrounded by four normal dielectrics is investigated.Under the consideration of material dispersion,the dispersion equations for the TE oscillating guided modes are obtained and mode dispersion curves are plotted.It is found that zero-order TE oscillating guided mode is exist.With the increase of mode number,mode dispersion curves move to left,and their cutoff frequencies decrease.Besides,some modes have three dispersion properties: normal dispersion,abnormal dispersion and mode double-degeneracy.

A phenomenon experimentally emerging in super-continuum generation with a piece of photonic crystal fiber pumped by quasi-continuum wave is reported.According to the numerical simulation which contains using the gain spectrum theory of modulation instability and solving nonlinear Schrdinger equation,it is proved that this phenomenon is generated by modulation instability.After the results of the simulation and the experiment being contrasted and analyzed,it is found that the simulation result including two mentioned methods is in excellent agreement with the experiment result which the wavelength difference between the two spectrum lobes and the central wavelength are 27.08 nm and 32.72 nm respectively.

To study the thermal effect of planar waveguide packaging properties,the situation of adhesive bonding is modeled by the finite element method,and the thermal stress and the axial micro-displacements of the adhesive are analyzed.The regular pattern of the adhesive stress birefringence is calculated qualitatively based on the basis of the photo-elastic theory,and the results show that the edge of the bonding interface region is the most sensitive to temperature change.The optical power loss generated from the axial micro-shifts is also proposed by beam propagation method,and if the excess loss is 0.15 dB.It is found that the thickness of the adhesive should be less than 16 μm.The influences of package performance following temperature changes and different thickness of the adhesive under the same conditions are also summarized.

The transmission characteristics of the coupled-resonator optical waveguides based on the two-dimensional triangular-lattice photonic crystal are studied by the multiple-scattering methods and the finite-difference time-domain method.Through selective inserting the rods with different radius between two adjacent microcavities,the coupling intensity between the two adjacent point defects is weaken,and the group velocity can be further reduced by three orders of magnitude.

KTP planar waveguide is formed by combining ion implantation with ion exchange.The influence of ion implantation on the ion exchange waveguide are studied.The characterization of the waveguide is studied by the prism-coupling method,and the results indicate that positive change in refractive index occurs in the waveguide region.The irradiation damage and the Rb distribution are analyzed by means of the Rutherford backscattering spectrometry technique,and the results show that the lattice damages formed by ion implantation act as a diffusion barrier at about 2.8 μm under the surface,which stop the Rb ion and K ion exchange in the deeper depth.

A method both convenience for generation and calculation for anticipated ASE waveform in spun fiber Raman amplifier,by analyzing the NLSE of signal and pump wave in fiber,is proposed.According to its time domain characters,a non-Gaussian noise ASE model is established and the term is added to the NLSE simultaneously by considering birefringence rotation effect in spun fiber Raman amplifier.By solving the equation with Split Step Fourier Method,ASE in spun fiber Raman amplifier is investigated.Numerical results for the ASE noise power spectrum are validated.

A system for measurement to obtain Neural Contrast Sensitivity Function(NCSF) is constructed,according to the relationship between Modulation Transfer Function(MTF)calculated from wave-front date and Contrast Sensitivity Function(CSF) with a wide range of spatial frequencies.Compared with previous measurement method,the coherent noise and speckle noise can be avoided using the proposed method which are brought in by the interference of laser beams,and white-light NCSF can also be provieded.The green-light and white-light NCSF are acquired with this technique for different eyes.It is shown that NCSF,which is independent of the optical system of eye,for green-light is higher than that for white-light under the condition of the same luminance.The maximum value of CSF appears at 8 c/deg of the green-light and white-light,while the maximum value of NCSF of the green-light and white-light appears at a higher spatial frequency of 12 c/deg.

The complete pathological tooth model and the criterion of caries lesion extent are established.With the programme of Monte Carlo simulation algorithm,the process of fluorescence excitation and transmission in tooth tissue is completely simulated and the relationship between the changes of optical parameters caused by the tooth tissue lesions and fluorescence distribution of QLF ia also explored.And,the legitimacy of the process above is verified using fluorescent functional of tracepro software.With the increase of lesion extent in dental caries part,the results show that the difference of fluorescence distribution between healthy and diseased tissue are increased with the increase of scattering coefficient and the reduce of absorption coefficient and fluorescence quantum efficiency.

The FLS900 Steady-state fluorescence spectrometer is used to test the normal and alcohol blood in vitro when radiated by continuous laser,and the variation components in blood and the fluorescence characteristics decayed with the time are obtained.The results show that the location of the fluorescence peak can not change when excited by 407 nm laser,only the intensity of the emission peak in the 605 nm decreases slowly.But the fluorescence spectrums have a wave mutation in 14 hours and 10 hours respectively,and have a strong fluorescence peak in the 474 nm eventually.Through the analysis,it can be concluded that the laser can put off the decay time of blood in vitro obviously and also can partly repaired the erythrocyte destroyed by the alcohol,but continuous irradiation by laser led to the change of cells morphology and then accelerated the hemolytic process,thus produced a lot of fluorescence material-reduction of nicotinamide adenine dinucleotide.The result will supply a valuable reference to the research on activity of the blood cell and the functional structure of the blood.

The diffusion equation describing the light transportation in two dimensional two layers dental model with finite size is solved by finite element method,and the optical intensity distribution inside the dental tissueis is obtained.The penetration depth is defined and analyzed when dental enamel and dentin is under different optical parameters.It is revealed that penetration depth decreases with the increase of scattering coefficient of dental enamel,but increases with the increase of scattering coefficient of dental dentin.In the case of variation Rate of penetration depth to scattering coefficient,dental enamel is much larger than dentin.And,the Monte Carlo random statistical method is used to verify the correct of solution of diffusion equation based on finite element method.

A new tunable chromatic dispersion (CD) compensating method is presented based on the nonlinear effect of semiconductor optical amplifier (SOA). The compensation effect and range of dynamical chromatic dispersion is simulated and analyzed using the XPM of SOA on the 10 Gbit/s and 40 Gbit/s RZ code systems. The analyzing results indicate that its compensating range can reach 400 ps/nm in the 10 Gbit/s transmitting system and 40 ps/nm in the 40 Gbit/s transmitting system. The experiment of dynamical chromatic dispersion compensation is conducted in the 10 Gbit/s transmitting system on the basis of the analytical results. The experimental result shows that the dispersion compensating rage of -40～60 ps/nm is realized.

A novel reconstruction method based on RBF neural networks is proposed for restoring the degeneration Fiber Bragg Grating(FBG) strain sensor.According the correlation analysis of bridge′s FBG strain monitoring sites and none-linear approximation of RBF neural networks,the degeneration FBG strain is reconstructed by the regular and the most correlative strain sensor,which assures more accurate and accords with practice.Simulation results verify the effectiveness of the designed method and theoretical discussions.

The uplink laser communication signal from a submerged platform to a satellite is simulated using Monte Carlo method with certain communication system parameters and reasonable channel parameters.The temporal and spatial distributions of received signal and the relations between signal and telescope′s field of view are analyzed.The signal to noise ratio of the receiver is calculated,which educes the optimized field of view of 3° and sample time slot of 15 μs.Then the error probability of the communication system is computed for laser pulse position modulation (PPM) and maximum likelihood detection.The results show that the error probability is below 10－4 when horizontal distance from satellite to laser signal center is less than 5 km.Consequently,the uplink laser communication between a submerged platform at 60 m depth and a satellite can be achieved under slightly severe environment.

A full-duplex radio-over-fiber system with sextuple optical millimeter-wave generation transmit OFDM signal utilizing two parallel phase modulators is proposed.2.5 Gbit/s OFDM signal is modulated on the optical millimeter wave with 60 GHz frequency and transmitted to the base station over standard single-mode fiber(SMF).The generation principle and the transmission performance over fiber of optical millimeter wave generation are analyzed by theory and simulation,respectively.The results show that OFDM have more advantage than NRZ in ROF system.

The chromatic dispersion and nonlinear performances of 16DPASK modulation format in optical communication are analyzed.Based on the modulation and demodulation principles of this optical signal,the optimal extinction ratio for back-to-back configuration is theoretically derived as 1.43 dB,which is verified by simulation.Then transmission system model of 16DPASK is established.Simulation results show that the spectrum width of 16DPASK is one quarter of that of BASK.Both the chromatic dispersion and nonlinear tolerances of phase tributary are larger than that of amplitude tributary.

The moire fringe′s amplitude distribution is analyzed by using the frequency domation analyses of Fresnel diffracting.The formula of small angle measurment using the grating pair composed of the same gratings is gained.The formulas gained by frequency domain analysis are the same with those gained by geometrical method.The results show that moire fringe is composed of lots of vertical small fringes.To measure the small angle directly by the change of the width of the moire fringe,a initial angle is needed,and it′s value is decided by the magnification of detector′s optical system,the angle measuring precision,the size and the resolution of the detector.

A new method for the measurement of polymer optical fiber (POF) properties based on the principle of spread spectrum communication is introduced.The spectrum of optical signal is spread by modulation using pseudo-random sequences (PNs) and injected into the POF,and the output optical signal is detected by a photoelectric diode then dispread with the original PNs.According to the principle of spread spectrum communication,the interference and noise after the process of dispreading are bated effectually,the signal-noise ratio (SNR) of the signals after dispreading improves evidently,and the measurement accuracy of signal waveform increases.The results from simulations and experiments show that this method can be used to detect week signal waveform under a background of strong noise and interference where the SNR is -20 dB or under.

Quantitative density reconstruction of an object in detonation process using high-energy flash radiography is described.In order to obtain the path length of the object,the radiographic image of the object is corrected by an integrated nonlinear function that represents the nonlinear imaging process of the high-energy flash radiographic system.The function is measured from the image that is obtained from a pre-knowing sample,and the sample is structural similitude with the object.The path length is reconstructed by algebraic reconstruction technique with the rule of least error.Then the density distribution of the object is obtained form the result of reconstruction when the mass absorption coefficient is deducted.A series of density reconstructions of a static radiographic test object is obtained by the radiographic system,and the results show that the errors of the density reconstruction are approximated to 10%.

An interferometer is designed based on the schematic of zone-plate with a total optical path to test aspheric surfaces.The MZP is designed and manufactured through testing a hyperboloid,of which radius of curvature R is 103.26 mm and caliber D is 40 mm,writing program based on coordinate transformation stripe center method to process the interference fringe.Compared with results of identical hyperboloid tested by Taylor-Hobson,the method is confirmed feasible and advanced.

The impact on the absorption-dispersion properties in an M- type five-level atomic system interacting with external fields system are discussed by using numerical analysis.It is shown that changing the control fields can influence the absorption-dispersion properties regularly.The electromagnetically induce transparency windows can be obtained if the parameters are taken appropriately.The number of transparency windows is proportion to the number of control fields and the width of the transparency windows is related to Rabi frequencies.It is found that the electromagnetically induce transparency windows in the system narrow gradually as decreasing control fields Rabi frequencies while the dispersion of medium would be enhanced and slow-light would be realized.

For studying the entropy exchange between the subsystems of the interaction system of a atom with the field in a leaking cavity,an exact solution of the master equation that describes the system by using the method of super-operator is obtained.The influences of the intensity of the cavity-field,the dissipative coefficient of the cavity and the Stark shift between two atomic levels on the linear entropy are discussed.The results show that: the more intense the cavity-field is,the longer the persistent time of the exchange of the entropy between the cavity field with other sub-systems is.When the two-level Stark shifts between the atomic levels changes to enhance the coupling between the atom and the cavity field increased and the cavity dissipation coefficient remain unchanged,the entropy of the system speed up the exchange and the steady-state values of the entropy become smaller.

The quantum statistical properties of the superposition state, which involve two arbitrary coherent states |β〉 and |mβeiδ〉, are investigated from two aspects, such as the phase distribution and Winger function. The results show that the non-classical properties of the superposition state depend on β2, amplitude coefficient m, the phase difference between the coherent states δ, and the phase difference between the superposition coefficients . When selected suitable parameters the superposition state exhibits quantum effect. The phase distribution and Wigner function of an equally populated mixture of two coherent states are derived, too. By comparison the results show that the presence of the coherence terms makes the superposition state with full quantum-mechanical behavior.

The development of a novel push-type ultrasonic endoscope is described in which probe rotation is accomplished by a small motor situated near the transducer. A digital FPGA-based ultrasound imaging system is implemented which uses coded excitation to increase the SNR and penetration depth, with probe rotation accomplished by a small motor situated near the transducer replacing the external motor and the long steel wire used in other ultrasonic endoscopes. The apparatus is tested continuously for 300 hours with no obvious problems. The coded excitation, digital quadrature demodulation imaging system can obtain ultrasonic images of higher quality and more information of the echo is preserved compared with the analog imaging system, because the analog digital conversion is moved to the first step of the signal processing.The digital imaging system possesses a higher SNR resulting in a sharp image. Locating the motor near the probe improves the consistency of rotational speed in comparison with external guide-wire rotation, and increases the image quality and life-span of these devices.

By analyzing two significant facors,skin physical characteristics and system characteristics,which affect the multispectral face recognition,a novel Band-Adjusting HOSVD (BA-HOSVD) multispectral face recognition algorithm is proposed.The spectral factor is treated separately with the weighted fusion method,which retains more information of the spectrum.Simulation results show that BA-HOSVD can be applied in multispectral face recognition,and it has a better recognition result than the other methods which do not consider the band characteristics.

Aiming at the character of visible image,a new contrast intensifying technique is presented using segmented histogram nonlinear extension.For the image being intensified effectively,the specific image is cut into three parts (target area,transition area and background area).Based on the characteristic of each part,different gray scale transforms are designed to carry out image nonlinear transform (the uneven transverse extension of the image histogram).Then using the gray-level redundancy equilibrating.The result shows that the technique can increase the contrast and suppressing the background.

A new edge extraction method based on ACS and gradient is proposed.Due to information feedback,the complicated problem can be resolved by the simple ants.The new food definition and movement mechanism to the ant is applied in this study.Multi-scale gradient is taken as the food objective of the ant.Besides,two directional functions included strong and weak one for prior directional searching are used,and the pheromone is graded.Furthermore,the thresholding is automatic for the final edge extraction.According to the compare with other methods in the experiment,the efficiency of the proposed method is proved,and the method is not sensitive to the noise.

Through introducing CMOS image sensor LUPA-1300-2,the application of multiple slope integration function in the spatial transient light detection system is investigated.Based on ACTEL corporation′s Flash FPGA APA600 as the hardware carrier,the drive and control for the sensor are analyzed and designed.The experiment results show that the function is able to detect the instantaneous changes around the spatial transient optical point,and enhance system′s reliability and capability of information collection.