This paper descrlbes the experimental investigation of stimulated Raman scattering obtained from a multimode fiber.10 orders of stimulated Stokes scattering of wavelengths ranging in 546～702 nm have been obtained from a 480m,multimode,low-loss,graded quartz fiber pumped by a 532 nm frequency-doubled YAG:Nd laser beam with a pulse duration of 7 ns,output power of 0.7MW and repetetion rates of 5 and 10 PPS.

The grating at near grazing incidence used for pulsed dye lasers has been further improved. Two problems has been solved of inserting the intracavity etalon and of selecting the optimal blazed grating and its orders at grazing incidence.A new version has been presented in which the grating and the etalon are arranged symmetrically.Single-mode operation and the output linewidth of the order of a few hundred MHz(below 0.006A)can be obtained.

Transmission and coupling losses for EH11wave guide mode were analyzed and calculated,and the effects of the bending wave guide axis on laser oscillation were considered.A sealed-off intra- cavity wave guide CO2 laser have been developed on this basis.This paper describes the configuration of the device and the experimental results.The diameter of the wave guide tube,discharge parameters and cooling etc are discussed.

It is shown experimentally that three major factors must be considered to obtain a CO2 laser with long life-time.They are:1)elimination of slow gas leakage,2)selection and oxidation of electrode material,3)decreasing the decomposition of CO2 molecules.We have done in the following ways:laser tube is not dried but filled with water vapor,the electrode material must be degassed in vacuum and oxidized by filling oxygen gas.When pure silver electrode is employed,gas mixtures constitutions of 1)CO2-N2-He-Xe-H2O,2)CO2-CO-He-Xe-H2O,3)CO2-N2-CO-He-Xe-H2O, the operation life-times are respectively 1)10,476 hours,2)9185 hours(still in operation),3) 9207 hours(still in operation);while pure nickel electrode is used with CO2-N2-He-Xe-H2O gas mixture,operation life-time is only 1644 hours.

This paper reports on the results of the investigation of the holographic properties and some application experiments of Ce-Bax Sr1-xNb2O6 single crystals.The factors such as the composition of crystal,the contents of Ce dopant,the exposure level and the orientation of crystal face have influences on the holographic properties.Maximum diffraction efficiency of Ce-SBN is over 90%. An exposure level is 14mj/cm2 with an efficiency of 10%.As recorded with an Ar+ laser,the optical storage sensitivity of the crystal is higher,and a He-Ne laser can be used for recording,reading and erasing.

The basic princilpes and testing methods are described concerning laser speckle interferometry of such mechanical parameters as plane displacement,rotating angle and vibration,and the problems of sensitivity are discussed.Demonstrations are given.

Laser was used for rapeseed breeding and a new rape strain of earlier maturity and higher yield has been selected.In comparison with the original ones,it matured three days earlier with 15% raise of yield.Good results have been obtained in large area planting.

A preliminary conclusion was drawn that argon laser in the treatment of traumatic parap- legia injury,incomplete and complete,seemed to be superior to other clinical methods of treatment.

In this experimental study,YAG:Nd laser beam was applied directly on the cock’s comb to evaluate its effect on vascular tissue.The YAG:Nd laser used had a wavelength of 1.06 μm and an output power of 25 watts,It’s spot size was constant at 2.5 mm.Biopsies were taken at an interval of 30 minutes after irradiation. Histopathologic study of cock’s comb wounds were carried out by common and electron microscope,which showed that the tissue impairment produced by YAG:Nd laser was similar to that of thermal burns,varying from superficial 2°to deep 2°～3°,depending upon the exposure duration to laser beam.In addition,the histologic study showed that YAG:Nd laser impaired the tissue with a three dimentional effect.

Since April 1978,He-Ne laser beam(20 mW)have been using for treatment of patients suffered from adnexitis in our hospital.The fields for irradiation on the patients were selected according to the related points of acupuncture.The results were quite satisfactory.The to tal effective rate was as high as 93.6% for the patients with moderate to severe symptoms and signs. Two of them proved to have tubal obstruction were pregnant after treatment. Some patients with followd-up laboratory survey showed that their abnormal ESR rate and WBC count had returned to normal value. Basal body temperatures,vaginal smeans for hormonal evaluations and urinary pregnandiol estimations that the dosage of the laser beam used did not alter normal ovarian functions. After the treatment,the abnormally high viscosity of blood found in these patients had restored to normal range and the changes were usually proportional to the degree of the clinical improvements. The related or subjected area to laser beam of the experimental rabbit showed same degree of capillary dilatation and plasma exudation. The above results were only our preliminary findings,and more extensive studies must be conducted before any definite conclusion can be drawn.

Experimental results of nitrogen molecular laser irradiation on tumors found in several groups of white rats,the observation of changes in their main internal organs and immunized organs,and the pathological changes in their tumors are described.Investigations in cancer cell culture after the application of nitrogen molecular laser irradiation on sarcomas S180 of white mice is also reported.These indicate that the irradiation not only strengthen the immunity of the body,but also arrest the growth of tumors. These show that the irradiation may be a comparatively ideal unspecific origin of stimulation to step up the organic immunization and nitrogen molecular laser may be used as a new auxiliary means to cure malignant tumors.

Pantial liver lobe resection with a CW Nd-YAG laser as light scalpel were carried out in ten adult rabbits,which showed the usefulness of the focused Nd-YAG laser beam in liver surgery. The output power of the laser was 15～20 watts.Measurement of SGPT and blood routine were made preoperatively and postoperatively.The cut edge was bloodless with a 1～3 mm layer of carbonization and coagulation at the surrouding tissure.24 hrs after operation,SGPT increased to more than 130 units,and blood hemoglobin decreased seriously.Both SGPT and blood hemoglobin returned to normal level 7 days after operation.Under microscope,agglutinations of erythrocyte in venules was observed within the necrotic zone 2 mm from the cut edge.The submicroscopic structure of the hepatic cells observed by electron microscope showed different degree of thenmal damage according to their distance from the cut edge.Within distance of 3 mm from the cut edge,the submicroscopic structure was not complete,however,those situated 4～5 mm from the cut edge showed complete submicroscopic structure.Autopsy perfomed 1 to 3 months postoperatively revealed satisfactory healing and liver regeneration without infection.

Experimental results of excised wounds in the skin of 71 rabbits irradiated respectively by lasers are reported with emphasis on morphological and histologic investigation.No effect was observed for He-Cd laser,while obvious effect was manifested for He-Ne laser and CO2 laser. Preliminary conclusion is that the mechanism for promoting the healing of wounds may be the circulation improvement of blood and lymph,as well as stimulated generation of fibrOblasts.