Heat transfer problem is very important in fusion splicing process of photonic crystal fibers (PCF) due to the potential distortion which can be introduced when exposing the structure to high temperature. Such heating is further complicated to internal air-structures of PCF. The heat transfer of fusion splicing PCF and theorize for confirming the optimal fusion splicing conditions are investigated. Based on heat transfer and conservation law of energy, a three-dimensional axisymmetric conductive heat transfer model is built using a CO2 laser as heat source, the transient heat transfer in fusion splicing process of PCF is simulated in order to avoid collapsing the air holes. Experiments and analysis shows that the heat transfer model may find out heat transfer characteristic of PCF fusion splicing process, and provide theory basis for confirming optimal fusion splicing conditions.

Laser diode pumped optical parametric oscillator (OPO) laser is operated in the orthogonal porro-prism resonator. The 1.57 μm eye-safe laser with high mechanical stability, high thermal stability and high beam quality is obtained base on the KTP typeⅡnon-critical phase-matching. A linear polarized-oscillating condition exists in the resonator, and the field of the pump laser for the OPO can be homogenized. The laser solves the problems such as unstable signal output in the intracavity OPO and optical damage due to the exorbitant intracavity power density. The OPO laser is operated in the heat-conducted half-circular LD arrays pumped Nd:YAG laser, and produces the average pulse energy of 86 mJ at 20 Hz in a 5.4 ns pulse with an optical-to-optical conversion efficiency of 9%, the energy stability of ±2.5％, and the beam divergence of 5 mrad.

The experimental results of high-efficiency 2.7 μm laser are demonstrated on quasi-phase-matched single-resonated optical parametric oscillator(OPO) in periodically poled lithium niobate with MgO(PPMgLN) pumped by 1064 nm laser of elliptical beam. Theoretical analyses of PPMgLN grating period tuning is presented. When grating period is 31.3 μm, a PPMgLN OPO could get output at wavelength of 2.7 μm. The pump beam polarization matches the e→e＋e interaction in PPMgLN (5 mol% MgO-doping), thus maximal nonlinear coefficient d33(27.4 pm/V) is effective and walk-off of beams can be avoided. When pump power was 78 W with 8 kHz Q-switch, an average output power of 11.8 W at 2.72 μm was obtained with slope efficiency of 19.5%, with 24 W at the corresponding idle wavelength of 1.75 μm. The M2 factor of 2.7 μm laser was 2.04, 5.56 in parellel and perpendicular direction respectively.

In order to get uniform gain distribution to reduce thermal effect, coupling system was optimistically designed by means of lens compression and wave-guide equality to improve the uniform of gain distribution to 90%. The numerical simulation module on unsteady resonator was established to analyze the change of the beam quality with time in heat capacity laser. The experimental results show that kilowatt level of burst power with 2.7 times diffraction limit is gotten.

A tunable multi-wavelength erbium-doped fiber (EDF) laser based on nonlinear polarization rotation (NPR) is realized. A polarization-dependent isolator and a polarization-maintained fiber (PMF) are used as key elements of the laser. Both effects of self filtering and peak clamping generated from NPR, effectively alleviating the mode competition resulted from the homogeneous broaden of the EDF, ensure stable multi-wavelength operation at room temperature. The dispersive property of the cavity loss allows the lasing wavelength to be tuned within a range of 5 nm. Wavelength spacing can also be tuned by changing the effective length of PMFs, the period of the self filtering is determined by the birefringence of the cavity. Stable multi-wavelength operation with wavelength spacing of 0.25 nm and 0.75 nm is obtained as two pieces of PMFs and a polarization controller are combined into the cavity.

It is the most difficult point for high power semiconductor lasers to improve the abilities of lasers to resist catastrophic optical damage(COD) and work characteric of LDs. According to the principle that the energy gap of film materials can be influenced by internal strain stress, direct current magnetron sputtering has been used for preparing AlxNy dielectric films with different stresses under different deposition conditions. Broad area semiconductor lasers with a new no-absorption window has been designed considering cavity degradation of devices, peak power output has increased by 46.5 percent for the new structural device, perpedicularity divergence angle is up to 21°, parallel divergence angle is up to 6.1°. It has been less than 0.091 percent of aging speed per thousand of the LDs after testing of 2000 h aging.

Kilowatt high power diode laser is reported with the ways of multi-wavelength and polarization coupling. The fast and slow axis beam parameter product is symmetrized by the method of shaping with the beam quality better than 12 mm·mrad and all-solid-state laser. 87.5% optical-optical efficiency of the high power diode laser is obtained. Through intelligent control, the diode laser can be outputted with different wave lengths, powers and pulse widths.

Separate heat source profile basing on structure of semiconductor laser array is applied in thermal resistance calculation of microchannel heatsink as boundary condition. Relationships between emitter width，position and thermal resistance are presented and optimized length of microchannel at different semiconductor laser arrays′ cavity length are also gotten through numerical calculation .Semiconductor laser array, with 1mm cavity length, 100 μm emitter width and 25% fill-factors is packaged on the presented microchannel heatsink and tested. With an exterior size of 27 mm×11 mm×1.5 mm，thermal resistance of microchannel heatsink reaches 0.34 K/W and matches the need of high power semiconductor laser array′s cooling.

A dual-ring permanent magnets structure is presented, which can be used as Faraday cell in four-mode differential laser gyro so as to provide appropriate intensity and axial uniform magnetic field. The analytic expression of the magnetic filed distribution along the ring magnet axes is deduced, which is proved thereafter theoretically and experimentally. The conception of magnetic homogeneity is introduced. The distribution curve of the dual-ring magnets is simulated with different intervals and the characteristics of magnetic field distribution are calculated in given homogeneities. In the end, an appropriate design scheme of Faraday cell in four-mode differential laser gyro is proposed.

By numerically solving the extended nonlinear Schrdinger equation, it is shown that Raman-induced self-frequency shift (RIFS) can be manipulated by third-order dispersion (TOD) in photonic crystal fibers (PCFs). In the anomalous dispersion regime, RIFS can be decreased by the positive TOD and enhanced by the negative TOD, respectively. The enhancement of RIFS by negative TOD can be suppressed by the spectral recoil effect. The variation of peak intensity and profile of input pulse plays an important role on RIFS. In the normal dispersion region, the influence of TOD on RIFS is nonsignificant due to the rapid temporal spreading.

The novel technical scheme of super cavity is proposed. Using Compton scattering theory, the high brightness laser synchrotron source (LSS) based on the technique of super cavity, including radiation wavelengths, photon yield and radiant power, are calculated and discussed. The effects of the electron beam quality and the laser power loss on the photon yield and radiant power of laser synchrotron source are discussed. The results show that the γ-ray with energy up to 10.975 MeV are expected to be produced by Compton vertical scattering of far-field infrared laser photons on the 3.5 GeV electrons bunches, the photon yield of a single electron are direct proportion to the power and wavelength of laser, and inverse proportion to the sectional area of laser beam. The radiant power of a single electron is direct proportion to the power of laser and square of Lorentz factor, and inverse proportion to the sectional area of laser beam.

The Raman spectra of different brands blue ballpoint pen ink marks were measured by confocal micro-Raman spectroscopic technique. The Raman spectra were excited with 514.5 nm radiation. According to characteristic Raman bands, intensities and its trend, we can simply and quickly identify the ink marks of different brands blue ballpoint pen. Many points were chosen to be measured from the same brand blue ballpoint pen ink marks, and the Raman spectra keep consistency. For the same brand blue ballpoint pen ink marks, we track to measure their Raman spectra for a year and a half and it is found that Raman spectra of the same brand blue ballpoint pen ink marks made in different time have certain regularity with time going on. These lay the foundation for the quantification of the time. The results will offer scientific evidence for court to identify the types of ink marks and provide sufficient evidence for the commits such as altering the signatures in the contracts. The methods have the advantages such as high-speed, simplicity, no pretreatment, and particularly non-destructiveness.

The model of subwavelength grating (SWG) with several dielectric layers under it is established based on the rigorous coupled-wave approach (RCWA). SWG is introduced as reflectors to the InP based long wavelength resonant cavity enhanced photodetector (RCE PD) design. Simulation demonstrates InP based SWG’s reflectivity is lager than 99.7% in the center wavelength 1.55 μm and wide reflection bandwidth (the reflectivity is higher than 99% from 1.40 μm to 1.62 μm) is achieved at the same time. Compared with pure DBR , the total number of reflector's layers is no more than 9 (4 pairs of DBR and one SWG). Thus it is an innovation of designing long wavelength RCE PD by SWG reflector (SWG-RCE PD) instead of DBR. And the results of simulation show that SWG-RCE PD’s quantum efficiency is about 90% at 1.55 μm and the product of crosstalk attenuation and quantum efficiency is more than 15 dB.

Based on the extended Huygens-Fresnel principle, the analytical expression for the spectral degree of coherence of partially coherent annular beams propagating in atmospheric turbulence is derived by using the quadratic approximation of Rytov’s phase structure function, and the spatial correlation properties are studied. It is shown that the oscillatory behavior and phase singularities of the spectral degree of coherence may appear when partially coherent annular beams propagate in free space, and the oscillatory behavior becomes stronger with increasing the beam obscure ratio ε. However, the oscillatory behavior becomes weaker and even disappears as the strength of turbulence increases. The curves of the spectral degree of coherence of partially coherent annular beams with different values of ε are close to each other and turn into Gaussian-like profile with increasing turbulence. The larger ε is, the less the spatial correlation is affected by the turbulence. In addition, it is found that in free space for small α the mean-squared width of the spectral degree of coherence wc can be either larger or smaller than that of the spectral density wi depending on ε， and critical value ε0 increases with increasing α. As α increases, there is wc>wi for different values of ε. However, there always exists wci when the turbulence is strong enough.

Lorentz-Gauss beams have been introduced to describe some certain laser sources with high divergence. When the q parameter at the source plane tends to infinity, Lorentz-Gauss beams reduce to be Lorentz beams. Based on the Collins integral formula, an analytical propagation formula of a Lorentz-Gauss beam passing through a paraxial abcd optical system is derived. Within the paraxial framework, the propagation properties of Lorentz-Gauss beam are illustrated with numerical examples. Based on the vectorial Rayleigh-Sommerfeld integral formulae, the analytical propagation equation of a nonparaxial Lorentz-Gauss beam in free space is presented, and the corresponding numerical examples are also given. Moreover, the far field expression and the scalar paraxial result are dealt with as special cases of the general formulae.

Recently, the widely used Stokes parameters are generalized from one-point quantities into two-point counterparts, and used to determine the degree of polarization and degree of coherence of stochastic electromagnetic beams. On the basis of the generalized diffraction integral formula for an ABCD optical system in spatial domain, we derive a propagation law for the generalized Stokes parameters of a stochastic electromagnetic beam passing through an ABCD optical system, and use the Stokes parameters to investigate properties of the state of polarization of stochastic electromagnetic beams. As an example, we study the changes in the state of polarization of a stochastic electromagnetic Gaussian Schell-model beam propagating through a dual-focus system.

The beam combination characteristics of partially coherent beams, which are aligned along one dimension, are studied by use of Wigner distribution function. The formulae of intensity profiles, beam propagation factor (M2) and kurtosis parameter (K) are derived. The analysis shows that the intensity profiles,beam width, beam propagation factor (M2) and kurtosis parameter (K) are dependent on the spatial coherent length, propagation distance, separation and numbers of the beamlets.

According to principle of lidar and experiences, the automatic alignment system of lidar beam controlled by computer procedure has been designed. By controlling the position of gimbal-mounted mirror, the direction of light beam scanning was east-west and south-north. Echo signals were analyzed, and final position was obtained to make transmitting and receiving systems parallel. The process needs 10-20 min for once, and accuracy is about 0.1 mrad. In atmospheric temperture monitoring, measuring results compared with CIRA86 data. The error of altitude at 30-45 km is 1-3 K, 2-5 K for 45-65 km.

The principle and progress of polarized beam coherent combination is described. The influence factors, such as beam parameters, the change of amplitude-ratio and phase-difference, beam overlap-ratio and parallelism on the combining efficiency, are researched. The experimental parameters and methods of operating combining are also discussed. The results show that the influence of phase-difference variation on combining efficiency is much greater rather than the change of amplitude-ratio, and the effect of the overlap-ratio error is so small that it can be ignored when it is smaller than 2.5%. Moreover, the parallelism error makes the combining efficiency have a significant decrease. It is found that combining beams with large beam diameter have a benefit for the effective reduction of combining loss caused by the parallelism error, the combining efficiency is greater than 95% when the beam diameter is 8 mm and interference of equal thickness is used to test the coincidence. In addition, beam combination with identical intensity is the best method for getting the maximum intensity and simplifying operation.

An experimental scheme was established for noninvasively measuring the characteristics of light propagation along human meridian direction. The diffuse emittance of the arm skin along the pericardium meridian and non-meridian directions for 658 nm light radiation were measured. The influence of the light chopped frequency and the meridian block on the detected signal was investigated. Our study suggest that the light attenuation along both the meridian and non-meridian directions conforms to definite law. There is a high significant difference between the propagations along the meridian direction and non-meridian direction (P<0.01). Furthermore, the chopped frequency and the meridian block can affect the detected signal. The diffuse emittance signal decreases with the chopped frequency’s increment in the range of low frequency(10-370 Hz), and the relative difference of detected signal along meridian and non-meridian directions increases with the block force’s increment. These research results are important and valuable for interpreting the human meridian phenomena and the physical-chemical characteristics of acupuncture point and meridian by biomedical optics.

The thalassemias are a group of anemias result from inherited defects in the production of hemoglobin. The current techniques for screening and diagnosis of thalassemia are time consuming and complex. A laser tweezers Raman spectroscopy (LTRS) setup was used to trap single erythrocyte from patients with thalassemias and normal donors, and to collect the Raman scatting of trapped cell. Blood samples obtained from 11 patients with non-deletional HbH disease (HbH-CS), 11 patients with β-thalassemia major, and 11 normal controls, were tested. Principal component analysis (PCA) algorithm combined with back-propagation neural network predictive model was performed to distinguish abnormal erythrocyte. The PCA results reveale that the difference between normal controls and HbH-CSs is significant with the predictive accuracy of BP network as high as 97.90 %. The predictive accuracy between normal controls and β-thalassemias major is 90.72 %, and 86.28 % between HbH-CSs and β-thalassemias major. These results tally closely with the corresponding averaged Raman spectra. Under different experimental condition, the predictive accuracy showes similar results. This pilot study can serve as a useful probe for developing a rapid, simple, reagent-free method for distinguishing of thalassemia erythrocytes.

In order to determine the repair role of laser in the damage induced by ultraviolet-B (UV-B) radiation, the effects of He-Ne laser (5 mW·mm-2) irradiation on Ca2+-ATPase， Mg2+-ATPase and Na+/K+-ATPase activity in six days seedlings of wheat after enhanced UV-B (10.08 kJ·mm-2·d-1) radiated were studied. The results showed that the Ca2+-ATPase activity and Mg2+-ATPase activity under UV-B handling were lower than CK group(P+/K+-ATPase in contrast (P＞0.05); the Ca2+-ATPase activity, Mg2+-ATPase and Na+/K+-ATPase activity under the He-Ne laser radiation were higher than the CK group(P2+-ATPase, Mg2+-ATPase activity were higher than the one under UV-B handling, but lower than CK group, Na+/K+-ATPase activity was higher than CK group. It suggested that He-Ne laser can improve ATPase activity. It indicated that the damage of wheat seedlings induced by UV-B radiation can be repaired partly by He-Ne laser.

In order to simplify the thighbone tumor surgery and improve the accuracy of the areas to be cut, a kind of surgery orienting model for the surgery operation is designed according to the scanning data of computer tomography (CT) and the three-dimensional reconstruction image. By using the Dimetal-280 selective laser melting rapid prototyping system, the surgery orienting model of 316 L stainless steel is made through orthogonal experiment for processing parameter optimization. The technology of direct manufacturing of surgery orienting model by selective laser melting(SLM) shows obvious superiority with high speed, precise profile and good accuracy in size comparing with the traditional ones. The model has been well applied in a real surgery operation for thighbone replacement operation. The successful development of the model provides a new method for the automatic manufacture of customized implants and surgery model, and will build a foundation for more clinical applications in the future.

With the development of nuclear power industry, the heavy section stainless steel vacuum vessel presents many challenges to joining methods. The conventional welding processes can’t satisfy the strict accuracy and quality requirements due to its higher heat input. In this paper, a 3500 W Slab CO2 laser and a 20 kW fast axial flow CO2 laser were applied to weld austenitic stainless steels with a plate thickness over 10 mm. The autogenous laser welding, narrow gap laser welding with filler wire and laser-tungsten inert gas (TIG) hybrid welding with filler wire were exploited respectively. Meanwhile, the joint microstructure and properties were studied. The experimental results shown that welds with good appearances and no holes and cracks could be obtained with laser beam welding techniques, and the joint microstructures and properties are satisfied with the service requirements.

An antijamming chaotic lidar system with high resolution for automotive collision warning radar application is proposed. Utilizing the broad bandwidth chaotic light emitted from a laser diode with optical feedback as the probe beam, we can locate the target by the correlation characteristics of chaotic light. Further, the velocity can be obtained by time differential method. Experimental results show this real-time chaotic lidar can obtain sub-second measurement period and 9 cm range resolution. Simulative results show that, as automotive collision warning radar, the chaotic lidar has good antijamming capability, can resolve the false alarm problem resulting by the multi-channel and noise jamming.

There is physical processing of laser energy absorption and attenuation in coaxial powder flow. Theoretical models of temperature fields for carrying gas/powder two phase flow from coaxial nozzle have been presented from Beer-Lambert law. Based on the models, the calculated simulation of temperature field in powder flow has been achieved. The influences of laser cladding parameters, such as laser power, powder mass flow rate and gas flow volume, on temperature distribution have been discussed. Temperature field in powder flow has been measured by CCD camera. It is shown from both simulated and experimental results that temperature in centre axial line of powder flow will be significantly increased from outlet of nozzle to part surface. It is available to laser cladding.

For improving the understanding of laser-metal inert gas (MIG) hybrid welding, the effects of laser power, arc current and groove gap on critical speed of this process are studied on Q235 mild steel with thickness of 4 mm. The results show laser power and arc current are direct proportional to the critical speed of hybrid welding. The maximum and minimum critical speed, vmax and vmin are mainly determined by the laser power and arc current, respectively. Increasing groove gap can both increase vmax and vmin but the effect on vmin is bigger. In the experiment, the effects of groove gap on vmax and vmin can reach 20% and 35% respectively. Moreover, the reliable welding speed range of hybrid welding, Δv is increased with laser power. For the constant laser power, increasing arc current will decrease Δv.

The analysis formula of cavity photon flux for chemical oxygen iodine laser(COIL) and NCl(a)-I all gas-phase iodine laser(AGIL) is obtained using the chemical dynamics model of continuous wave cavity. The profile of cavity photon flux along the flow direction and the total output power has a simplified analysis formula for COIL but no for NCl(a)-I AGIL due to its complexity. Comparison and estimation for COIL and NCl(a)-I AGIL have been finished as viewed from the energy extraction and volume/weight efficiency.

The primary experiments of pulsed discharge of mixing gases of O2-N2-CH3 simulated in N2-chemical oxygen-iodine laser (COIL) are investigated. The pulsed discharge profile of current and voltage, deposited energy and discharge uniform are explored and some results and trends are obtained.

To obtain barium titanate ceramics with excellent microstructure and properties, barium titanate ceramics doping alkali metals ion Ca2+ and the rare-earth Y3+ is synthesized by wide-band laser sintering. By means of scanning electron micrscope (SEM), X-ray diffraction (XRD), thermogravimetry-differential thermalanalysis (TG-DTA) and TR-8401 static-of-spring, the microstructure and properties of barium titanate ceramics are characterized. The experimental results show that Ca2+ doped into ceramics, restrains the growth of grain size, improves temperature stability of barium titanate ceramics, prevents the hexagonal phase barium titanate and improves the curie temperature of barium titanate ceramics, while Y3+ doped into ceramics, makes the microstructure of barium titanate ceramics be compacted, the room temperature resistivity of barium titanate ceramics be decreased and barium titanate ceramics have characteristics of semiconductor.

Laser sinter technique for (Ta2O5)1-x(TiO2)x (x is 0.3, 0.4 and 0.5, respectively) based ceramics was briefly introduced in this paper. Thermal compensation of (Ta2O5)1-x(TiO2)x based negative temperature coefficient materials could be allowed by combination of laser sinter and annealing in oxygen, which tuned their dielectric temperature coefficient nearly to zero. Dielectric properties of specimens prepared by conventional sintering, laser sintering and its annealing sample in oxygen were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results showed that thermal compensation of the negative temperature coefficient materials related to the oxygen defect, and led to the change of their temperature coefficients.

An organometallic compound, [(CH3)4N]2[Cu(dmit)2] (dmit2-=4,5-dithiolate-1,3-dithiole-2-thione), abbreviated as MeCu is synthesized. Its nonlinear optical absorption properties dissolved in acetone with concentration of 2×10-3 mol/L are studied using the open-aperture Z-scan technique with 40 ps pulse width at 1064 nm and 15 ns pulse width at 1053 nm, respectively. The sample shows two-photon absorption when irradiated by 40 ps pulse at 1064 nm and the two-photon absorption coefficient is 4×10-13 m/W. While excited by 15 ns laser pulses at 1053 nm, strong reverse saturable absorption is found and the nonlinear absorption coefficient is estimated to be as high as 7.07×10-11 m/W. The nonlinear absorption properties of the sample at different laser intensities and the optical limiting with 15 ns pulse at 1053 nm are also measured. All the results suggest that this material may be a promising candidate for the optical limiting application.

Measurement of the fiber composition and content is important for textile testing. At present, the widely used testing methods require complex sample preparation and rely on the subjective judgment, which decreases testing efficiency. The rotating linearly polarized light imaging method is based on multi-incident and detection polarization angles images. By fitting the polarization difference as function of these multi-incident and detection polarization angles, a characteristic parameter related to fiber microstructure is obtained. The common textile fibers can be easily discriminated by this characteristic parameter. Based on the measurement results of single component fiber, it is feasible to detect the component and content of blend fibers by this technique. This technique has the advantage of non-destructive operation, in vivo testing, and rapid speed.

In this paper, a gas detection system using intra-cavity laser spectroscopy technique is designed. It can be used to measure the concentration of multi-gas. Through analysis of the basic architecture and principle of gas detection system, the different standard concentration of acetylene gas is measured and the performances of gas detection system have been evaluated by calculating the absorbance of standard gas, such as detection sensitivity of the system, repeat accuracy and measurement precision. The experimental results indicated that the repeat accuracy of the gas detection system is less than 0.07. The detection sensitivity and measurement precision is less than 0.03％ and 0.17％, respectively.

A novel application of tilted fiber Bragg gratings(TFBG) for measuring the bending curvature and temperature simultaneously and independently is reported. The coupling-strength variations of the lower cladding modes provide information on the curvature as they are responsive to curvature changes but unresponsive to temperature, whereas the wavelength shifts of the core-mode peaks facilitate measurement of temperature because the core mode is unresponsive to curvature changes but responsive to temperature. Therefore, those features allow using a single TFBG for simultaneous measurements of temperature and bending curvature. The proposed scheme can be used to solve temperature-cross problem in the real applications.

Selection of locating feature point in X-ray detection images for laser weldments with complex structure was discussed, mathematic models of defects depth and deviation were established, and spatial distribution feature of defects in precision weldments was determined. Automated extraction algorithm of defects spatial location data was provided, the quick extraction of defects spatial location data in laser weldments with complex structure was achieved, and experimental verification was proceeded. The results show that the extracted extraction algorithm is feasible. Three-dimensional model of laser weldments with complex structure are established after the spatial location data of defects is input, the visualization of spatial location for bulk defects in laser weldments with complex structure is achieved.

In the calibration methods for high energy laser(HEL) energy measuring equipment, the online calibration method can eliminate vourous effect imposed on measurement results by extrinsic elements. Three online calibration methods were introduced to analyse the theories and data treatment processes. Since several parameters are unknown, least square fitting method was used. The ratio of reflectivity to the spectroscope transmittance was calibrated online to eliminate its uncertainty imposed on the measurement results. By analyzing and comparing data of the three methods conclusions show that direct transfer method is the simplest which can eliminate effect caused by environment elements, laser beam spot characteristic, and so on. Indirect transfer method can eliminate the effect caused by almost all extrinsic elements including change of the ratio of reflectivity to transmittance, but its calibration processes are complex, its uncertainty in measurements is the biggest. Calibration processes of intersectional transfer method are simpler than indirect transfer method’s. It can also eliminate effect caused by changes of the ratio of reflectivity to the spectroscope transmittance, and its data treatment processes are the simplest.

An improved gas absorption spectrum measurement setup is proposed. A super fluoresent source (SFS) has been used to measure the infrared vibration-rotation spectrum of 2ν3 band of H13C14N (HCN) molecule successfully. The configuration of double pass backward (DFB) type SFS, the molecule structure of HCN and fundamental modes of oscillation were introduced, the SFS output power was fixed at 2mW, J=0-27 rotation energy levels were excited. The flatness of spectrum is less than 1 dBm from 1525.3 to 1560.3nm, and over fifty absorption lines are measured directly without scanning and data fitting. The high brightness and wideband properties are utilized in the scheme, the structure is simpler, and the cost is cheaper than traditional measurement method, and it can be used to study the molecule fine structure in the laboratory.

A new 90° 2×4 hybrid for coherent optical communication systems was designed based on the birefringence effect and the electro-optic effect of crystal. It consists mainly of four pieces LiNbO3 crystal plates with the same sizes which are modulated by the electric fields and a polarization analyzer. Two of LiNbO3 crystal plates split respectively incoming signal beam ES and local oscillator beam ELO into four beams of laser lights and another LiNbO3 crystal plates mix them into two synthetic beams by birefringence effects. The desired phase relations between the respective output ports can be obtained by the electro-optic effect. By adjusting the applied voltages on the LiNbO3 crystal plates, 4 output ports from the polarization analyzer give the mixed beams which are phase shifted by 90° relatively to each other. Compared with traditional optical hybrids, the optical hybrid has the advantage of low losses and good stability of the phase shift.

A wavelength selective monolithically integrated photodetector array is fabricated and characterized, which can be used for reconfigurable optical add-drop multiplexers. The integrated device consists of GaAs/AlGaAs Fabry-Pérot resonant cavities and InP-In0.53Ga0.47 As-InP PIN photodetectors on the GaAs substrate. In order to achieve multiple channel routing detection, the thickness of GaAs-based resonant cavity is varied by wet etching, and then regrowth of the resonant cavities are accomplished by using the second epitaxy. High-quality heteroepitaxy is realized by employing a thin low-temperature buffer layer. The device is operated at a wavelength around 1500 nm for four channels with 10 nm interval. A spectral linewidth smaller than 0.8 nm, an external quantum efficiency of about 12%, and response rate of 8.2 GHz are simultaneously obtained in the device. The experiment result exhibits good agreement with the calculation.

A reconfigurable all-optical logic gates with not-inverted data technique is demonstrated by using a single semiconductor optical amplifier (SOA) and a tunable optical band-pass filter (TOBPF). Based on cross-gain modulation (XGM) and four-wave mixing (FWM) in the SOA, multiple Boolean calculation of the return-to-zero signal is realized, and different logical functions are switched by adjusting band-pass filter center wavelength and optical signal power. In the experiment, all-optical multiple logic gates of AND, NOT, NOR, NXOR,·B, and A·B functions at 10 Gb/s are demonstrated without changing the experimental setup. In order to obtain not-inverted RZ data, the clock signal is used for the probe signal which is benefit to combining the basic logics to complicated logic gates.

Terahertz technology has great potential application; terahertz wave has broad\|band which isn’t occupied. It has following features: higher data transfer rate，good direction, higher safety, lower scatter, higher transmittance and so on. Terahertz technology is becoming a research focus in communication field in developed countries. The paper introduces several key technologies and analyses latest achievement, basing on the framework of terahertz communication. At the same time, the paper foretells developing trend and application prospect and put forward the terahertz development strategy.

The principle and configuration characteristics of fiber delay lines (FDL) are analyzed, which are becoming research hotspots. Categories of fiber delay lines are concluded and three important application fields of fiber delay lines are tailed after particularly. At first, in fiber sensing and optical measurement field, the paper analyzes laser line-width measurement system, crystalloid birefringence measurement system, optical coherence tomography (OCT) measurement system and optical correlation spectroscopy (OCS) measurement system. The primary function and parameter setting of fiber delay lines in these systems are pointed out. Secondly, it analyzes the principles and system configurations of high-speed pulse code generator, hybrid optical buffer and optical encoder /decoder in optical communication field, including some essential problems. Thirdly, in detail, it analyzes multi-tone photonic oscillator, microwave fiber delay line, optical A/D converter and optical signal correlation processor in microwave photonics field. At last the paper proposes that the research directions of fiber delay lines are improving delay time precision, realizing delay time regulation continuously, reducing insert loss and improving engineering reliability. Overcoming these problems is the key for wide application of fiber delay lines.

Rapid repair technique of aircraft damage is the requirement of military operations and training. It's also an important support to ensure the mastery of the air in modern high-tech war. With the development of new structural materials, traditional aircraft damage repair techniques have failed to meet the demands, with their shortages being analyzed. For its unique superiority, laser technique for the damages repair of aircraft structure is summarized, such as laser cutting, laser welding, and laser cladding used for battle field damage, corrosion and wear, including the conception of functional gradient material. Alloy powder system, microstructure, micro hardness regularities of distribution, resistance to wear and fatigue behavior of laser cladding are investigated. The merits of laser cutting are explained, and a mobile laser material processing system is introduced. Meanwhile, the need for further research is also briefly discussed.

There is the photobiomodulation (PBM) of laser irradiation or monochromatic light (LI) on biosystems. The quantum mechanics of the interaction of LI and cellular molecules determines PBM dosage. The PBM of low intensity LI, -10 mW/cm2, is mainly mediated by state-dependent extraocular phototransduction, but the PBM of moderate intensity LI, 102-103 mW/cm2, is mainly mediated by reactive oxygen species mediated signal transduction, both of which support our biological information model of PBM (BIMP). The signal transduction pathways can be classified as two kinds, pathway 1 mediated by the Gs protein mediated pathways, and pathway 2 mediated by the other pathways such as protein kinase Cs mediated pathways and mitogen-activated protein kinase mediated pathways. Almost all the present pathways found to mediate PBM belong to pathway 2, but pathway 1 mediated PBM has been predicted according to BIMP.