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1.
    
650 nm AIGalnP/GalnP laser diodes with compressively strained MQW active layer have been successfully fabricated by means of single epitaxy growth. The threshold current is 6.4 mA,at 40 mA CW operation, the fundamental transverse-mode still remains, and the output power and the slope efficiency can reach 34 mW and 1.1 mW/mA respectively. The dead output power in CW operation can reach 66 mW at a saturation current of 88 mA. During 200 h burn in test,the laser diodes show good stabilization with a degradation of less than 8 %.  相似文献   

2.
Recently,some feasible ways have been put forwardsto determine the thermal focal lengthfTof gain mediumin end-pumped solid-state laser ,such as CCD-photo-graph[1]and stable cavity condition[2].However ,thismethodinvolves the complicated experi mental setup andcannot be directly applied for high power pump due tothe saturation effect of CCD.Stable cavity conditionmethodis relatively si mple,but since there is no laseroutput when the stable cavity just turns into unstablesome parts of energy o…  相似文献   

3.
    
Supercontinuum(SC) generation in a dispersion-shifted fiber(DSF) pumped by a 10 GHz regeneratively mode-locked fiber laser(RMLFL) is presented. Optimization of pump wavelength leads to a 20 dB bandwidth of 58.73 nm,which covers the whole C band and part of L band. Using an angle-tuning thin film filter, multi-wavelength and pico-second pulse trains of low chirp could be chosen from the SC spectrum. Amplified spontaneous emission(ASE) induced degeneration of the achieved pulse trains is observed and discussed.  相似文献   

4.
    
We have demonstrated a laser-diode pumped Nd.GdVO4 extra-cavity frequency tripling ultraviolet laser with a LBO crystal in this paper. Under the acousto-optic (A-O) Q-switched operation, we have obtained 355 nm ultraviolet laser,with pulse width of 25 ns and pulse repetition rate of 20 kHz. By using a type Ⅰ non-critical phase-matched LBO crystal, the SHG output power of 822 mW is achieved at the incident pump power of 16 W. The output power of 355nm UV laser is 260mW with a type Ⅱ phase-matched LBO crystal,and the conversion efficiency (1 064 nm-355 nm) is 5.9 %. The power stability of 355 nm laser is 1.7% in 1 h.  相似文献   

5.
A highly efficient and high power green laser generated by intracavity frequency doubling of a diode-sidepumped Q-switched Nd:YAG laser has been demonstrated. In the simple L-shaped cavity geometry,the maximum green output power of 28.5 W was obtained with a pulse width of 95 ns at a pulse repetition rate of 10 kHz by using a LBO crystal for frequency doubling,corresponding to a conversion efficiency of 11% from diode pump power to pulse green power. At a pulse repetition rate of 1 kHz,6.9 mJ of pulse energy,25 ns of pulse duration and 276 kW of peak power were obtained.  相似文献   

6.
    
Inrecentyears,diode pumpedall solid statelasersin blue[1],green[2]andred[3]spectralreginsofintracavity frequencydoublingweredeveloped,becauseoftheirpromisingadvantages,suchasdesignsimplicity,highef ficiency,structurecompactness.Inmedicine,opticaltes ting,andcolordisplaytechnology[4],laserradiationfrom 550nmto650nmisrequired.Inparticular,theyellow laserat588.9nmradiationisveryclosetotheSodium D2atwavelength589nm,thereforeitwillbecomeani dealsourceinsteadofSodiumlamp.Atpresent,thesol id state…  相似文献   

7.
A diode-pumped Nd: YAG acousto-optically(A-O) Q-switched laser at wavelength 946 nm formed with a simple plane-plane cavity has been demonstrated. The maximum average output power was 850 mW. The highest peak power was 531 W with the pulse repetition rate of 20 kHz and pulse width of 80 ns at the incident pump power of 19.5 W.  相似文献   

8.
    
Optical couplers arei mportant componentsinthe sys-temof optical signal processing,optical communicationand optical calculation.Therefore many people areinter-estedinseekingfor those couplers with uniquefunction.Photonic crystals (PC)[1-2]have drawn great…  相似文献   

9.
    
With the rapid increase of global information capaci-ty,all optical wavelength division multiplexing(WDM)networks are very attractive because they are capable ofprocessing broadband optical signals without convertingthem to electronic signals.Large channe…  相似文献   

10.
    
A new class of multilength, constant-weight and two-dimensional multiwavelength optical orthogonal code (2D MWOOCs) with large capacity and good correlation properties is constructed based on multilength one-dimensional (1D) OOCs. The performance of these new MWOOCs in an OCDMA network with double-services is analyzed. The result shows that media with the shorter codeword performs much better than the media with longer codeword, and OCDMA system with these new multilength MWOOCs performs well. These features allow multimedia transmission of large capacity in OCDMA system.  相似文献   

11.
    
In many image resolution enhancement applications, the blurring process of the imaging system is unknown. This paper discusses the problem of single image blind resolution enhancement without estimating the point spread function (PSF). A regularization model is constructed for image enhancement based on the prior informaton of image error and image gray value,which does not need any prior in- formation of PSF. Moreover, through the solution of Euler equations, an an isotropic nonlinear diffusion equation are obtained,which can avoid the high computational cost of regularization model. Furthermore,in order to get sub-pixel superresolved image, the regularization model for image enhancement is extended to the enlargement of image, which can enlarge and enhance image at the same time. Last,to get clearer edges, a high frequency enhancement filter is used on the superresolved image. Numerical results show that the new model can get much clearer super-resolution images than traditional methods, and the peak signal to noise ratios (PSNRs) are also higher than traditional methods.  相似文献   

12.
  总被引:2,自引:0,他引:2  
In mobile atmosphere laser communication,the fastand accurate beamsteeringis one of the key techniquesfor acquisition,tracking and pointing(ATP) of laser sig-nals .Compared with the normal loop-locked trackingand pointing system composed of fast steering …  相似文献   

13.
    
Small diameterpipesareusedwidelyinmanyfields, suchasenergyindustry,chemicalindustry,aviation,weaponmanufacturingandsoon.Theinspectionof thesepipesisveryimportantbecauseofthebadworking conditions.Therearemanymethodstoinspectthepipeswithinnerdiameterslargerthan20mm,suchasthe wholecircleimagemethod[1],theringopticalcutting imagemethod[2],thelaser beamscanningdisplacementmeasuringtechnique[3],theCCTVcameramethod[4], Omni directionalmethod[5]etc.Butfewmethodscande tectthepipeswithaninnerdiameter…  相似文献   

14.
    
Recently,the dispersion-managed solitons(DMS) areof great interest in soliton communication systems .Be-cause of some prior advantages compared with conven-tional solitons ,such as higher pulse energy and signalnoise ratio,lower averaged dispersionline an…  相似文献   

15.
  总被引:1,自引:0,他引:1  
Thereis cold-heat exchange under the large tempera-ture gradient in the space environment ,andin space-to-ground laser communication links the optical reflectorson a satellite in orbit someti mes need to be placed out-side the capsule.Therefore,tremendous thermal distor-tions will occur onthe optical mirror surface,which maybring shift andspreading ofits reflectedfocus andthere-by influences the performance of space-to-ground lasercommunicationlinks . Although there are many reports on thermal…  相似文献   

16.
    
In recent years ,the demand of the project survey grewincreasingly,sothetorsionsensor has obtainedextensiveattention.But the related studies about optical fiber tor-sionsensor are veryfewinthe domestic andforeign[1-3].Inthe traditional torsion sensor we p…  相似文献   

17.
    
Pre-configuration Cycle (p-cycle) is a promising ap-proach for protecting working capacities in WDMnet-works because of its ability to achieve ring-like recoveryspeed while maintaining the capacity efficiency of amesh-restorable network[1].The first and t…  相似文献   

18.
  总被引:1,自引:0,他引:1  
FiberBragggrating(FBG)isasignificanttechnology thatisusedtodesignkeydevicesorcomponentsinthesystemsoffibercommunicationandfibersensing[1], suchastunablefiberlasers[2],WDW/DM[3],WADM[4],tunablefiberfilter[5],fiberdispersioncom pensation[6],gainflattingofEDFA[7],FBG typeinter ferometer[8]andfibergratingsensors[9,10].OneofthekeyresearchissuesonFBGdevicesistomakethetun ingwavelengthdeviceswhichhavegoodcharacteristics ofwidetunablewavelengthrange,stableoutput,goodmultiplexingcapability. …  相似文献   

19.
20.
    
No matter designing and manufacturing a FBG pres-sure sensor ,or monitoringthe strain on material surfaceby using FBGas a pressure sensor ,the difficult technicalproblems to be solved are as follows :first ,howto effec-tively couple and propagatethe external stresstothe ax-ial direction of FBGthrough the underlay material ;sec-ond,howto make the FBGpressure sensor achieving aneffect of enhancing sensitivity;third,how to ensure alinear relationship between FBG′s reflection wavelengthand t…  相似文献   

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