The characteristic of type Ⅱ noncritical phase matching and the thermal effect caused by high pump power are taken into account. An unidirectional operation is realized by using a λ/4 wave plate, a λ/2 wave plate and a Faraday rotator, and a proper cavity to reduce thermal distortion is designed. An intracavity frequency doubled Nd:YAP/KTP ring laser end pumped by an fiber coupled diode array with output power of 1.0 W at 540 nm is developed. In free running operation, the intensity fluctuation is less than ±1.5%, the frequency stability is better than ±5 MHz.

In this paper, a kind of AO Q switched Nd:YAG laser with one oscillator and one amplifier is studied. The oscillator and the amplifier are composed of two Nd:YAG rod pumped by Krypton lamp and one AO modulator. The maximum average output power is 169 W. Under the condition of repetition rate 1 kHz, the pulse width is 70 ns, and the maximum peak power is 594 kW. The laser beam is delivered by an all silica fiber with diameter of 0.6 mm and focused by a group of lenses with new designed. A large scale laser deep engraving is realized.

An all solid state, tunable Yb:YAG laser pumped by two laser diodes was realized. A CW output of 66mW at 1049.5 nm was obtained with an absorbed pump power of 900 mW. The slope efficiency was 12.7% with output coupling of 1%, and the threshold was 410 mW. The tunability of the laser was studied in detail, and a tuning range from 1030.5 nm to 1055.5 nm was achieved. Self Q switched pulse train was observed.

The theory of FBG external cavity semiconductor laser with weak feedback is simply explained. Regarding the effects of feedback as a change of photons′ life and using the simple multimodes rate equation, the effect of FBG reflectivity on both the output power and SMSR is revealed.The conclusion is that there exists an optimum FBG reflection. The experiments using FBGs with different reflection show the same conclusion. A single laser mode with 25 dB SMSR is achieved.

The generation of high repetition rate (3～5 order harmonic of the RF modulation frequency at 2 5 GHz), amplitude equalized pulses directly from rational harmonic mode locked fiber ring laser is demonstrated by using the nonlinear transfer characteristics of LN MZI amplitude modulator. The theoretical analysis explains the experimental results well.

Using transfer matrix method with rate equations and coupling wave theory, a static and dynamic analysis of 3PS DFB diodes is presented. With vector processing rather than NR algorithm, the carrier density and photon density distribution biased at different injection current density are obtained.

This paper presents a low power sealed off RF excited all metal CO 2 laser. A 30 W TEM 00 mode output laser with power stability being better than ±5% from 750 mm discharge length was obtained. Far field divergence angle is smaller than 3.5 mrad and electro optic conversion efficiency is lager than 12.5%.

This paper describes a novel Smith Purcell FEL experiment with a relativistic electron beam of middle energy and a quasi optical resonator composed of diffraction grating and three mirrors reflector. Coherent radiation with peak power of a few tens of kW at 3 mm waveband is successfully detected from the experimental facility characterized by beam energy of 400～500 keV, pulse length of 70 ns ,pulse beam current of 0.2 kA, and pulse magnetic field of up to 1.2 T.

A study of the relation between instantaneous optical absorption and photovoltage in bacteriorhodopsin in room temperature by dye pulse laser with different wavelengthes indicates that: the photovoltage and optical absorption of the BR are not necessarily correlated, besides the amount of optical absorption there are other factors influcing photovoltaic conversion; and the photovoltage of BR at 617 nm is greater than that at 597 nm and 577 nm.

The upconversion and optical power limiting properties of a new organic dye trans 4 [4' (N hydroxyethyl N ethylamino)styryl] N methylpyridinium p toluene sulfonate (abbreviated as HEASPS thereafter) in DMF are reported in this paper. The two photon absorption cross section of HEASPS at 1064 nm is measured to be σ 2=4.7×10 -48 cm 4·s/photon by using a Z scan system. The linear absorption, single photon induced fluorescence, two photon induced fluorescence and two photon pumped upconversion lasing properties are studied. There is a red shift for the central wavelength of the two photon induced fluorescence compared with that of the single photon induced fluorescence and a blue shift for two photon induced lasing compared with two photon induced fluorescence. These phenomena can be explained by using the re absorption effect. Intense upconversion lasing at 626 nm is obtained pumped by a mold locked Nd:YAG ps pulse laser operating at 1064 nm. The upconversion efficiency from the pump efficiency from the absorbed energy to the upconversion energy is 26%.

A programmable pulsed power supply of hollow cathode discharge tube (HCD) for optogalvanic spectroscopy is fabricated. The optogalvanic signal of transition 5L 6 16900 7M 7 is measured. By adjusting the pulse width, pulse frequency, DC bias, as well as the output voltage, the optogalvanic spectra are obtained with good qualities. Spectra obtained by using different parameters were compared and discussed.

step Fresnel lens of high diffractive efficiency is fabricated by ion beam etching. Diffractive efficiency of Fresnel lens is important factor to evaluate the quality of Fresnel lens. The incident wavelength, except fabrication errors, has effect on diffractive efficiency of Fresnel lens for broadband diffractive refractive hybrid optical system. The effects of incident wavelength on diffractive efficiency of Fresnel lens are analyzed. Four kinds of laser source are used to measure the diffractive efficiency of Fresnel lens. It is pointed that the diffractive efficiency decreases greatly in short wavelength, but one decreases smally in long wavelength.

The relationship between polarization degree of the transmitted light and the parameters of the fiber sensing coil was deduced by using statistical average method based on the Jones matrix theory for the stimulated Brillouin scattering fiber optic gyros. The characteristics of the eigen state of polarization (ESOP) of the pump light and the stimulated Brillouin scattering light in the sensing coil were theoretically analyzed, and the conclusion about stability of the ESOP was obtained.

In this paper, a novel structure fiber optical gyro is proposed. It consists of a pair of calcite crystals oriented by 45°and adhered together, in which a polarizer and two directional couplers are integrated. Comparing with traditional IFOG, it has the advantages of simple structure, stability, small volume and low cost. The operation principle and method for signal detection are theoretically analyzed.

An optical system using a single electron trapping (ET) device with areaencoding of input fuzzy variables and negations is proposed to perform fuzzy logic operations in paralle. In this scheme, each encoding cell is only composed of one encoding cell so that the resultant pattern is still the image in which there is no space between any two pixel rows. Baed on the storage and erasure characteristics of the ET device, all of the fuzzy logical functions of two images can be implemented in parallel and spatial invariant by programming the illumination form of data arrays. No thresholding device, lens array and decoding mask is needed, therefore, this system exhibits high operation speed and large information throughout. The system can be compact. The experimental results are also given.

A new type of diffractive optical bar code (DOBC), which is different from the general bar code (GBC) and the hidden bar code (HBC) formed by CGH methods or grating modulated method, is proposed in this paper. Instead of reading bar code directly, the code information can be obtained from the first diffraction order of the bar code. The diffraction of the conventional HBC made by other techniques need to be focalized by a lens in its focal plane. By using Fresnel zone plate′s focusing function, and combining the HBC with Fresnel zone plate, a new type of HBC which has self focusing function is generated. The feasibility of the LHBC is proved by the experiments, confirming that the proposed HBC can be read more easily and has better performance than the HBC.

The laser confocal scanning microscopic (LCSM) system is one kind of modern microscopic instruments which is characterized by its depth discrimination capability. However, in order to obtain the three dimensional images of an object, the three dimension reconstruction is very importment. In this paper, The theories and methods of interpolation based on distance transformation from cross sections about LCSM system images are considered and obtain isotropic resolution three dimension image data.

WDM optical interconnection is a feasible method overcoming the problem of electronic bottlenecks for parallel computer system, the transmission properties of fiber make high capacity, low latency, low error rate parallel computer interconnection realistic. This paper discussed one kind of structures for parallel computer WDM optical interconnection, researched key technologies of it,and designed a test system. Analysis and test show that parallel computer system with ultrahigh capacity can be achieved by WDM optical interconnection.

In order to reduce the absorption and loss in the process of coating thin films, the weak absorption of the thin films coated on the Si plates at 1315 nm and their surface feature were measured by using surface thermal lensing method and atomic force microscopy, respectively. The factors that induce absorption are briefly discussed.

VO2 thin films prepared by vacuum annealing process were irradiated by 10 12 /cm 2 low fluence electron beam with energy of 0.8 MeV. Before and after irradiation the samples were characterized by XRD, UV VIS and Raman spectroscopy analyses. After electron irradiation the optical response to temperature was increased dramatically, the hysteresis extend was reduced, and the phase transition point was not changed obviously. And the transmittance of 370～900 nm was increased and absorptivity was decreased. The abnormal change of optical properties at metallic boundary was introduced by low fluence electron. Obvious change of XRD patterns and vibration peak were observed in samples before and after irradiation by low fluence electron.

A kind of novel nano crystal and polymer complex thin film PT PEK c was fabricated. The transmission loss of the complex thin film was measured accurately and real timely using photographic technique. The method involves a digital camera that has good spatial resolution and corresponding data processing software, the prism coupling system as well. It can be used over a wide range of loss values from 0.5 dB/cm to the order of 100 dB/cm. The transmission loss of nano crystal and polymer complex thin film PT PEK c at 633 nm is measured to be 3 09 dB/cm.

The influence of the crystal orientation of the substrate on microstructure is investigated by multi layer laser cladding with the powder of nickel base superalloy. With properly organized processing conditions, if the crystal orientation of the surface of the substrate is parallel to the preferred crystal orientation, claddings with the identical crystal orientation to the substrate can be obtained. The cladding layers exhibits fine and regular columnar dendrite except that a thin layer with altered orientation appears at the surface of the external layer. When the experiment was performed on other crystal faces of the substrate, there appears fine and random oriented dendrite.

Based on the quasi static and non coupling models, the FEM simulation on three dimensional transit temperature field of laser heating sheet metal is conducted, the temperature load is then converted to the nodal force, and the 3D thermal elasto plastic stress/strain fields are obtained. The main results show the forming mechanisms clearly.

With techniques of vibrating focusing beam and automatic powder feeding, a faultless laser cladding layer of Ni based alloy with single track width of 12 mm and thickness of 0.9 mm was obtained. Its hardness distribution, metallurgical structure and compositions were investigated and analyzed.