Using the system of fiber optic sensor in special coherence combined digital image processing setup and recording to moved number and direction of interferometric fringe and physical formula, collecting and processing image signal of vibration state is presented and professional software is studied and strain(time curve under random vibration state is measured after strain (time curve and vibration frequency for stable vibration were measured where they correspond with theory solution in this paper. This research provides a kind of new method for real -time vibration monitoring of structure engineering.

In this paper, the method of how to choose and stabilize the action spot of the gyroscope and the method of how to determine the action spot of the open - loop fiber optic gyroscope theoretically will be mentioned. At the end, the method of how to improve the measurement precision will also be mentioned by analyzing the experiment results.

This paper analyzes the mechanism of Cr4+ :YAG passive mode-locking and frequency doubled efficiency of KTP crystal. A suitable cavity has been designed to ensure the largest laser power density in Cr4 + : YAG and the parallel beam of light through the KTP crystal. By using Cr4+ :YAG as a saturable absorber, we have realized the passive mode-locking operation of a pulsed intracavity frequency doubled Nd:YAG laser and obtained the single pulse train with the output energy of 13. 5mJ at 532nm and with picoseconds pulse duration.

In order to express the relationship between the dilution and the processing parameters, The concept of dilution is formulated. The equation expressing the relationship between the dilution and the parameters of the laser coated layer and the processing parameters was derived based on metallographical measurement. The experimental method for determining the dilution in laser coating process by powder feeding method was designed. By varying the powder feeding rate Vf and scanning speeding Vs under definite laser power P and beam spot dimensions, coatings with different thickness were obtained. The dilution was calculated with the help of metallographical measurement. The factors which affected the dilution were studied carefully. When the powder feeding rate and scanning speeding Vs increase, the dilution become smaller. A reasonable explanation on why a minimum value is observed in the relationship between the scanning speeding and the dilution is presented. In the meantime, it is the theoretical foundation for further investigation on the relationship between the microstructure,mechanism of solidification and the processing parameters.

Laser forming is a new flexible forming method without rigid tools, the sheet metal is formed by internal thermal stresses induced by laser. On the base of analyzing the principal factors, the relativity between the material properties and temperature is considered, and a thermo - mechanical model is established. Meanwhile the laser spot is simplified properly, and the heat flux is exerted through a USER SUBROUTINE automatically. Using the finite element method, the three - dimensional laser forming process is simulated numerically. The forming process of a cylindrical part is analyzed, and the principal rules of planning the scanning paths in laser forming are put forward.

The microstructure distribution, surface hardness and residual stress of the 40Cr, which is modified by single - line solidification and folded - line solidification, are studied in this article. It is indicated that the surface micro-structure of the material treated by single - line laser solidification, is comprised of surface melting zone, sub - surface phase hardened zone and high temperature annealed zone connected with substrate. The difference between the folded - line laser solidification and the single - line solidification are the surface hardness and microstructure of the annealing region and secondary - hardened region. And the test of residual stress indicates that: in single - line laser rapid solidification, the maximal residual stress, which is pulling stress, emerges on the central line of the solidification zone. On the margin of melting zone, there exists compressive stress and in the heat affected zone there is pulling stress again. The residual stress of the folded - line solidification,and the later solidification zones bring stress on the former solidification zones and furthermore tempered the former ones.

The experiment of micro-ablation of ZiO~~2 ceramic by KrF excimer laser is described in this paper. The relationship between etching depth and laser pulse number, and the morphology of etching groove are investigated. The micro-holes with 40(m diameter and 25(m deepness are obtained. The results give the fundamental data for KrF laser ceramic processing.

Damage effects of CF/EP under the vacuum ultraviolet radiation were studied using a gas-jet type of vacuum ultraviolet simulator (BYO)for simulating the ultraviolet radiation in real space. Results of mass loss, inter - layer shear strength, SEM and XRD shown that obvious mass loss of CF/EP was produced and the surface was suffered a severe damage under vacuum ultraviolet. The inter- layer shear strength slightly increased at the original period of radiation and presents a remarkable decreasing trend as increasing the radiation time. The carbon fibers have no obvious changes and serve as a protector for epoxy matrix under the vacuum ultraviolet radiation.

In this paper , we use the laser technique in the ejection system successfully and design a new kind of laser ignition system .which can send laser energy to the seat ejection cartridges and make them fire to give out ejection force to eject the pilot from the cockpit ,the mechanism of the laser ignition system ,the equipment and experiment for checking the system are introduced in detail.

This paper introduces the design of optics, constant current source and temperature controller of a high power semiconductor medical laser. The instrument adopts 980nm laser with maximum power output of 2W as therapeutic beam and 670nm laser of 3mW as aiming beam. The laser beams, after being collimated , can either be transmitted directly or be coupled through an optical fiber. Whole system is controlled by a microprocessor. With appropriate hardware and software , weVe achieved a variety of protection features which keep the laser diode from damage , and obtained an accurate and stable output, both of which are vital to a safe and reliable medical laser .

According to the practical need of the multifunctional LD treatment apparatus, we apply a same driver to supply power for 667nm and 808nm LD. The designed driver is provided with some logic functions in order to avoid the electrical surge in the LDs when the driver is turned on and turned off. The driver can ensure that, when one of the 667nm LD and 808nm LD is powered, the other LD is not powered even though it is turned on. The driver has two control methods (hand-control and computer-control) and two running modes (invariable-power and invariable- current).

YAG double - frequency laser microbeam irradiated 4 - cell stage embryos of Bufo bufo gargarizans . The chromosomes were investigated in developed nomal and abnormal tadpoles of tail bud stage after irradiation with laser by use of technique of press slices. The results show that laser irradiation could cause chromosome doubling and chromosome elimination.

The heat conduction in frozen biological tissue irradiated by high - power short - pulse laser was investigated experimentally. The micro - scale film resistance thermometer with 1 JAS response time was used to measure temperature. The output of the film resistance thermometer was recorded dynamically by a YOKOGAWA DL2700 digital oscilloscope. The experimental results showed that, when the pulse duration is short, the heat conduction in frozen biological tissue is of non - Fourier behavior. The shorter the pulse duration and the thinner the biological tissue, the more notable the non -Fourier heat conduction. The power density and spot size will influence the maximum value of temperature during laser heating, and have nothing t& do with the problem whether or not the non - Fourier heat conduction can take place.

Objective The study was aimed to assess the effects of experimental transmyocardial revascularization with frquency- double Nd:YAG(KTP) laser (TMLR) on myocardial blood flow in zcute myocardial infarction2 -Smonth. Methods: Left thoracotomy was performed in 12 adult mongrel dogs. The medius of the left anterior descending artery (LAD) was ligated to creat the acute myocardial infarction. TMLR was performed with KTP laser in the acute infarcted LAD territory in TMLR group (n=6) and without any treating in control group (n=6). Myocardial perfusion imaging with 99m Tc - sestamibi SPECT was performed 2 - 3months after acute myocardium infraction both groups. Results; Myocardial perfusion SPECT imaging showed radioactivity deficit or decreasing of ra-diodistribution in anterior, interventricular septum and aex in both groups. There was no significant difference on the myocardium scores of radiodistribution between two groups. Conclusion: TMLR with KTP laser didn't improve myocardium perfusion 2 - 3 months after TMLR in acute myocardial infraction.

Objective: To study diagnosis value of Hysteroscopic examination for patients with behind menopause vaginal bleeding and safety of Nd: YAG laser ablation of endometrial polyps and submucous leiomyoma. Methods: A total of 139 patients with behind menopause vaginal bleeding were included in this group, recruited from the outpatient department of Obstetrics and Gynecology Hospital of Shanghai Fu Dan University during the period from April 1996 to October 2001. According to diagnostic outcome of hysteoscopic Nd: YAG laser ablation, respectively proceed dilation and curettage and hyste-roscopic Nd:YAG laser ablation. There is a contrast analysis between hysteroscopic examination and pathological diagnosis. Results: There were 100% sensitivity and particularly in diagnosis of endometrial carcinoma -uterine sarcoma-.submucous leiomyoma and atrophic endometritis by Hysteroscopic examination, sensitivity of endometrial polyps under Hysteroscopy examination was 97.1% , particularity was 100%. ．Hysteroscopic exarninatlon Was highly in accordance with pathologic diagnosis．All surgical operations were completed successfully．The average uterine depth Was 6．8cm(6—9)and the average operative time Was 3．0±10．2 minutes，patients with behind menopause vaginal bleeding were able to endure hysteroscopicexamination．No serious complications oc curred during or after ope ration．Th e intrauterine neoplasms disappeared in 83 cases a follow —up period of 1—3 month．Conclusion：Hysteroscopic examination is of great sign ificance for cause of disease behind menopause vaginal bleeding．For patients having diagnosed endometrial polyps and submucous leiomyma，hysteroscopic Nd：YAG laser ablation is an efective and safe approach of treatment.

Objective; To observe the clinical Effect of patients with upper gastrointestional polyp Treated by Ho: YAG Laser. Methods; 106patients with upper gastrointestionsl polyp were treated by Ho:YAG laser through endoscope . Results; Of the 106 case, the cure rates of esophageal polyp was 93% , cardiac polyp 80% , gastric polyp 98% ,duodenal polyp 100%. Conclusion; The advantages of treatment by Ho; YAG laser in upper gastrointestinal polyp was simple, less pain, safty, mild postoperative reaction.

Objective: To study the application of otorhinolaryngologic diseases treated by Low Power Laser. Methods; All 158 cases with otorhinolarynogologic diseases were treated by Low Power Laser such as He - Ne laser and C02 laser. Results: After follow-up of three to six months in the 158 patients, 71 cases were significantly efficient(45% ).77 cases were efficient(49% ). There was no charge in 6 cases(10% ). Conclusion; LPL is a safety and efficacious therapeutic method on otorhinolaryngologic diseases.

Objective : To explore the treatment of epiglottic cyst by Nd - YAGlaster. Method: Using Nd - YA-Glasterl26 patients of epiglottic cyst were treated. Result; 126 patients were followed up for 1 -5 years. Among them, 116 patients is cured including 12 cases with thicken of mucosa local and 2 cases with partial defect of epiglottic, which were cured 1 month later, and 8 cases recurrenced. Conclusion: Epiglottic cyst were eliminated by laster due to its laser thermo-therapy . It is improtant that appropriate power and irradiate time to prevent epiglottic cyst recurrenced or thickenof local mucosa, defect of epiglottic . Nd - YAG laser irradiation treatment of epiglottic cyst shows evident advantages such as simple maniplation, low cost, outpatiented.

Objective :To analysis the distribution, concomitant of the acumination condyloma in anal canal -lower rectum. To evaluate the therapeutic effect of CO2 laser and Nd: YAG laser treatment. Methods: Local anesthesia by lidocaine. Vaporization by CO2 laser directly or by fiber optic Agcl CO2 laser in some cases. Nd: YAG. Laser was also used in vaporization or hemostasis. Some patients with deep lesion were undertaken through anoscope. Re-sults:28 patients were treated 1 to 5 times with efficacy of 96%. The methods are safe, reliable and with no complication. Conclusions:laser therapy has been widely accepted as a simple and effective method to treat acumination condyloma. Nd:YAG laser has its unique advantage in the treatment of acumination condyloma in anal canal - lower rectum, especially its simplicity and efficacy for the lesion in lower rectum through anoscope.

Objective: To study the treatment effect on herpes zoster with He-Ne laser. Methods: 245 cases of herpes zoster were divided into two groups according whether using He-Ne laser or not , and +hey were analyzed from the days of crusts forming, exuviating and pain disappearing. Results: He-Ne laser can be effectually used in herpes zoster, it may help to make the crusts generating, falling cut and ache going away, which can reduce the days of illness.