As one of the important optical technique in the field of laser sampling, low efficiency beam sampling grating (BSG) is widely used in high power laser system. It is an off axis, binary phase, Fresnel zone plate. In this paper, the principle of the variable period grating′ formation process is analyzed perfectly and the transmissive function of the BSG is obtained. Based on the analysis, a new method is presented to fabricate the BSG with electron beam direct writing. Compared with the holographic method, the new method is simpler, cheaper, and more efficient to manufacture elements on a large scale.

In this paper, a 2×2 total internal reflection optical switch is designed and successfully fabricated by employing the thermo optic effect of polymeric materials. The extinction ratios of the non block 2×2 optical switch are larger than 27 dB at both the crossing and reflecting states. The driving power at the totally reflecting states is about 132 mW with a driving voltage of about 3 V and a related electric current of 44 mA. This driving voltage can be decreased to 50～60 mW by adopting electroplating. The insertion loss is also measured.

The waveguide manufactured by means of K + Na + ion exchange on the substrate of BK7 glass is analysed and its model of the index spread in K + Na + ion exchanged glass is analyzed by numerical calculations. A few factors that affect the index change are discussed in detail.

A new way of multiplexing fibre optic sensors for gas detection based on intra cavity spectroscopy with fibre lasers is investigated. An active mode locked fibre laser is used to address the sensing network and provide preliminary experimental results to demonstrate the principle of operation. It is a new technique for combining intra cavity spectroscopy with a sensor network and has the potential for multiplexing a few tens of gas sensors with low cost and high sensitivity.

The transmission characters of fiber Bragg grating Sagnac loop are investigated theoretically and experimentally. Optical envelope bandpass filtering characteristics based on asymmetric grating Sagnac loop which transforms grating bandpass resistance character into grating bandpass filter character and can be applied in optical fiber grating sensors are demonstrated.

In this paper, a kind of dual tunable narrow bandpass filter is proposed based on the structure of all optical active fiber ring resonator. The tunable bandpass filter′s wavelength tuning range is 39 nm, from 1526 nm to 1565 nm. By changing the power of pump LD, its finesse can also be tuned.

Near field optical data storage using solid immersion lens is an effective ways to pursue super high storage density. In this paper, a homemade experimental setup is used to execute near field optical storage experiment on azobenzene polymer (P CN) with solid immersion lens (SIL), and achieve 0 5 μm storage bit (with laser wavelength of 532 nm). Further more, the effects of different focus position and incident laser power are investigated.

Using phase encoded technique, the proposed joint transform correlator reduces greatly the strong dc component and cross correlations between each input target, and the conjugate cross correlation between the reference and input targets, which are existing in the classical joint transform correlator. All these achievements are accomplished in only one step. With the use of amplitude modulation, the correlation output is bettered greatly in terms of correlation width, correlation peak sharpness, and anti noise ability. At the end, computer simulation is given which proved the efficiency of the proposed method.

The effects of linear heat input and focus position on the HE130 alloy laser weld shaping quality using solid Nd:YAG laser welding process with continuous wave were experimentally researched. The efficient laser welding linear heat input of HE130 alloy plates with various thickness were established through experiments and the relationship of the efficient linear heat input with the weld penetration and weld penetration/width ratio was quantified. The laser welding efficient linear heat input curve of HE130 alloy and the matching curve of laser power and welding speed in the range of different plate thickness were successfully made. The optimal focus positions while laser welding HE130 alloys with various thickness were experimentally acquired to get the optimal weld shaping including the larger penetration/width ratio and good rear shaping of the weld. The relationship between the plate thickness and the optimal laser focus position was then quantified and the optimal focus position curve was given.

Laser surface cladding of Si 3N 4 powder layer on AA6061 aluminum alloy was carried out using a 2 kW CW Nd YAG laser. Subsequent laser surface melting of the layers gave a surface metal matrix composite (MMC). The microstructure and phase identification of the modified layer were examined using scanning electron microscopy (SEM) and X ray diffractometry (XRD) respectively. Cavitation erosion and electrochemical corrosion tests were also performed in 3.5% NaCl solution at 23℃. Finally the cavitation erosion mechanisms of the laser surface cladding modified layers were studied by surface morphology analysis.

The properties of a QCW LD pumped Yb:YAG microchip laser was first presented in detail. At room temperature, 1 64 mW average output power and 16 4 μJ pulse energy at 1 049 μm were obtained with a 10 at % doped Yb:YAG microchip crystal when diode current was at 2 15 A. The beam quality factor M 2 values were measured to be 1 37 and 1 15 in the vertical and horizontal directions respectively. Theoretical results of laser output pulse width and relaxation oscillation were consistent with experimental values by analysis of quasi three level rate equations of Yb:YAG microchip laser.

It is demonstrated that an actively mode locked fiber ring laser consisted of electro absorption modulator (EAM) and semiconductor optical amplifier (SOA). A 10 GHz, 10ps pulse trains with 0.4 nm spectrum width were obtained. The output pulse train can be stable for more than 6 hours without any feedback controlling circuit. The performances of the laser effected by the parameters of SOA and EA were analyzed.

A simple actively mode locked fiber ring laser for generating tunable picosecond pulses was proposed by using a F P LD as the modulator and a HiBi fiber loop mirror as a tunable filter. Wavelength tuning in a range of about 10 nm is experimentally demonstrated by changing the voltage on the PZT in the HiBi loop mirror.

In this paper, non uniform well thickness multi quantum wells (NWT MQWs) materials were adopted to widen the output spectrum of superluminescent device. A novel type of 1 55 μm high power wide spectrum InGaAsP/InP integrated superluminescent light source was fabricated based on the tilted ridge waveguide integrated superluminescent light source. The spectral halfwidth is increased from 20～30 nm with the uniform well thickness devices to 45～60 nm. The quasi CW superluminescent power of the device is over 150 mW.

On a basis of passively Q switched laser dynamical model, a rate equation of a passively Q switched intracavity optical parametric oscillator (OPO) was calculated and the dynamical process of internal OPO was discussed. The 1.57 μm parametric output with power of 15mJ is obtained and the one or several pulses were observed for different signal cavity reflectivity experimentally. The theoretical calculation was coincident with experiment results well.

A miniature superradiant NH 3 optically pumped far infrared laser (OPFIRL) with or without buffer gas N 2 was theoretically studied. Base on the mechanism model of buffer gas, synthetical relaxation time was calculated. By solving the semi classic density matrix equations, spectra and the operating gas pressure of NH 3 superradiant OPFIRL with or without buffer gas N 2 were calculated. It was found that by adding buffer gas, FIR power could be raised, and there existed an optimum ratio of gases mixture and an optimum operating gas pressure which was higher than that of pure NH 3 operating.

The discharge plasma characteristics of the RF sputtered Cu and Au in He gas are investigated. The sheath thickness and the real and imaginary part of the plasma impedance are obtained.In addition, on the basis of Gadyak′s RF discharge model, the electron density in the discharge plasma is calculated for different pressure and current density.

The preliminary understanding is obtained about the focusing of optical beams induced by cross phase modulation in three dimensional self defocusing nonlinear media. When the input amplitude of pump beam exceeds the critical amplitude, the probe beam begins to focus, and its spot size gradually becomes a crescent moon shape.

A novel method of measuring absolute X ray wavelengths using an auxiliary diaphragm attached to the planar crystal, which can accurately determine wavelengths without any reference line and any information or special position.

This paper introduced a method to testing small light spot produced by an optical system with high NA. By using technology of fiber probe detecting and PZT tube scanning of near field optical microscopy, the small light spot can be measured with high spatial resolution. The results show that a resolution of 50～100 nm can be obtained.

Presents small confocal inspection technology which is developed by incorporating a gradient index lens for non contact high precision measurement of small internal contours, and which combines high axial resolution and absolute position traceability of a confocal microscope with a small gradient index lens. This technology features a high axial resolution, small in volume, aim at lope surface, and absolute step position traceability. the Piezoceramic is used as an axial driving device ,with a linear range of ±5 μm and 2 nm displacement per driving step drived by triangular waveform voltage signal, and the displacement sensor with a linear range of ±50 μm and a axial resolution of 1 nm used as a position tracer. Experimental result shows the non continuous contours tracking and aiming can be achieved with a resolution of 10 nm and in a range of ±1 μm for a angle gauge block of less than 20 degree.

This article briefly describes the actuality of the laser technology development ,and compares the situation of the patent applications in our country with that in foreign countries in detail, and also presents the corresponding policies.