An analytical representation of the Zeeman laser beat frequency function is given. It is used as a frequency discrimination curve for frequency stabilization of a 633nm He-Ne laser. When the laser is stabilized to the minimum of the beat frequency curve, frequency stability is about 1-2×10-10, and the resettability is 1-2×10-9. This stabilized laser can be used for precision measurement and spectrosoopio experiment. It is also used as a second frequency or wavelength standard.激光

This paper discusses a method used in the testing of the optical system and optical reflection mirror. This method was based on the interference. The interferential pattern was expressed by the series of the Zernike circle polynomials. The coefficient of the series was obtained by Gram-Schmidt normalization method and the least square method. This paper also discusses the method for removing the adjust error and the error of the testing system itself. The wavefront error and OTF was obtained from the series of the Zernike circle polynomials.

A detailed discussion is made on phase-space motion equations and radiation field equations for free-electrons near the magnetic resonance in the axial and helical magnetic fields. Red-shift spectral broadening and gain enhancement for free-electron radiation are obtained near magnetic resonance. Our theory is applicable to variable periodic and taper helical wiggler fields.

A groove large-optical cavity (G-LOC) InGaAsP/InP laser has been fabricated on semi-insulating InP substrate. The fabrication process involves only a single step liquid phase epitaxial growth on a channeled substraote, and is thus simple and reproducible. The device combines the advantages of the groove laser and the LOC structure. In groove laser, the presence of a built-in real index waveguide makes it possible to obtain low-threshold, single mode operation, while the LOC structure posseseg the potential capability of delivering Jiigh output power. As a result, threshold current as low as 25 mA and an output power of 200 mW per facet have been achieved. The G-LOO Laser can be used as light source in applications such as optical oom-xuunication and Signal process, as well as integrated with, other optoelectronic devices.

A new kind of crystal, the O-axis Nd:YLF, is used to obtain the active, passive and active-passive mode-loking. The C-axis Nd:YLF emits at 1.053#m without inserting any polarizing elements in the cavity. The fluctuation of the emergy in a pulse train of the active-passive mode-looked laser is less than ±4%. The fluctuation of the pulse width is no more than ±10%.

The alternation of ferroelectric domain structure has been observed in doped LiNbO3 crystals when the rectangular electric current pulses are applied across the solid-liquid interface during crystal growth by Ozochralski-method. The correspondence relation between ferroelectric domains and modulated current has been demonstrated. Using this new method, LiNbO3 with one dimensional periodic laminar domain structures have been prepared.

The effect of oxide impurity on the physical properties of 62 ZrF4-8 LaF3-30 BaF2 (mol %) glass was studied by equimolecular substitution of BaO for BaF2. It is shown that oxide impurity decreases the infrared transparency beyond 6μm, lead to an additional absorption band at 1350 cm-1, and increases the glass transition temperature, the crystallization temperature and the viscosity of glass. The additional infrared absorption of oxide impurity in the fluorozirconate glasses result from the multiphonon process of the vibration of F—Zr—O bonds at 680 cm-1.

The fundmental regularities of governing the optical absorption properties of glasses colored with Cd(S, Se, Te) have been investigated and summarized. Some new results are obtained. (1) The absorption edge of the glass agrees with the energy gap of the corresponding semiconductor, and their temperature coefficients have the same sign and similar values. (2) The absorption coefficient (α) depends exponentially on the photon energy (E) at different temperatures, and on the temperature (T) at constant value of the photon energy. The relationship among them may be written as an empirical formular α=α0exip(AE+BT), where α0, A and B are constants.

Moderate conentration and well-distributed F centers were created in Li-Na doped KCl crystals through diffusion. Hg lamp was used for the centers conversion and FA (II)-FB (II) centers were obtained. Absorption spectrum of the crystal was measured at 77 K, in which double-peaks structure was displayed obviously. Luminous spectrum of FB(II)-FA(II) centers was measured at the same temperature. The luminous peaks of FB(II)-FA(II) centers are at 2.49 μm and 2.66μm respectively. Using the point ion model and taking into consideration the contribution of the seeond-nearest ions in the ion size correction, the unperturbed state of FA(Li) center in KOI crystal was obtained. Then energy level of FA center was oaloulated using perturba-iion method. The result is satisfactory compared with, the experiment data.

The structure of sodium aluminophosphate glasses has been studied as a function of composition by Raman speetroscopy. It is found that in glasses with Na2O/P2O5<1 and content up to 10 mol % A13O3, nearly all the alumina is six coordinated, the glass network is mainly built up of (PO3)nn- chains and rings; while in glasses with Na2O/ P2O5≥1 and 5≤A12O3≤20 mol%, A1o4 tetrahedra and different kinds of phosphate groups are formed; but when the Al2O3 conten exceeds 25 mol % and the ratio of Al2O3/P2o5≥0.63, the glass network is mainly built up of AlPO4 groups.

We have investigated the sum-frequency generation (SFG) of the 1.06μm beam with its harmonic beam or dye laser beam in disodium gulfosalicylate (DSS) crystal. The collinear phase-matching types, wavelengths and propagation direction of SFG in DSS crystal have been calculated and measured. The measured results are inagreement with the calculate ones, the characteristics of tunable SFG output have also heen investigated.

Using a comparative fluorescence method, two-photon absorption cross-section for a number of common laser dyes were measured. It was found that the two-photon absorption cross-section does not follow Schafer-Schmidt s geometrical model expression for most dyes. A simple empirical correction of Schafer-Schmidt s expression is proposed. The experimental results are compared with the value predicted by corrected expression and good agreement is obtained.

A method of image contrast reversal by using π phase filter is theoretically analysed. Conditions for forming contrast reversal image in output plane by means of addition of phase factor e±iπ on zero frequency in frequency plane are discussed. Experimental results are given. This paper offers a theoretical base for using π phase filter in optical information processing.

This paper discussed features of the interference type computer-generated holograms with wide fringes. A new "technique by using third order wavefront of the computer-generated holograms with wide fringes for testing aspherio surfaces has been proposed. It makes one possible to decrease the holographic fringe numbers about 62%. The feasibility and potentiality of the technique have been verified by the experimental result.

This paper reports our experimental results obtained by using high-purity LiNbO3 for photorefraotive effect which is induced by YAG:Na3+ laser beam. The spatial distribution of birefractive change have been measured. It is demonstrated that the spatial distribution of birefringence change is asymmetric. A plot of the photorefraotive as a function of various annealing temperatures and hold time have been measured. The induced changes in extraordinary Is 3-4 times as large as the ordinary index.

The deactivation rate constants by 6 different collision partners of vibrationally excited C6F6 have been measured for the first time using an IR-UV double resonance technique, for example, KO2= (8.8±0.4) ×103 sec-1.Torr-1, KCO22= (7.1 ±0.8) ×103 sec-1 · Torr-1 and KXe = (2.9± 0.47) × 104 sec-1 · Torr-1. The measured value of KC6F6 = (0.4±0.15)×106seo-1·Torr-1 agrees well with the Lambert-Salter empirical correlation.

Atoms are first excited and then ionized by two different laser pulgeg, respectively. When the energy per pulse of the ionizing laser is near 1J/cm2, the ionization is saturated. By measuring the relative number of ionized atoms versus the ionizing laser energy, we can easily obtain the photoionization cross section for the excited state of the atoms. The ionizing laser pulse is delayed until the exciting laser pulse is stopped. It aims to eliminate the contribution of the ionization signal produced by the exciting laser and to avoid the Stark shift produced by the ionizing lager. The pliotoionization cross section for Cs (72P3/2) at 532.0 nm has also been measured. The measured value is σI=6.5×10-18 cm3, which is close to Manson's calculation.