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LASER. PRESENTED BY Sanjeev Kumar Singh Dept. of Physics Avanthi Degree & P.G College. LASER AND ITS APPLICATION. Laser (Light Amplification by Stimulated Emission of Radiation). C ONTENT. HISTORY OF LASER BRIEF INTRODUCTION OF LASER B ASIC COMPONENTS OF LASER
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LASER PRESENTEDBY Sanjeev Kumar Singh Dept. of Physics Avanthi Degree & P.G College
LASER AND ITSAPPLICATION Laser (Light Amplification byStimulated Emission of Radiation)
CONTENT HISTORYOFLASER BRIEFINTRODUCTIONOF LASER BASICCOMPONENTSOF LASER CONSTRUCTION WORKING
HISTORY & THE DISCOVERY OFLASER. The maser which is the predecessor of the laser and emitted microwaves was first built in 1953. Some of the first work done on the laser was started in 1957 by Charles Hard Townesand Arthur Leonard’ at Bell labs. Their original work was with infrared frequencies but they later changed their focus to visible light and the optical maser which was how the Laser was first referred to. Working independently of Townes and Schawlow and of each were Gordon Gould a graduated student at Columbia University and Aleksandr Milkhailovich Prokhorov. All parties had the idea of using an open resonator which became an important part of the laser. In 1959 Gould applied to the US patent officer for a patent for the Laser but he was refused and the patent instead went to bell laboratories in 1960. The first working laser was built by Theodor Harold Maiman working at Hughes Research laboratories in MalibuCalifornia. Charles Hard Townes ArthurLeonard
The LASER beam was invented by the physicist MAIMAN in1960 One of the most influential technological achievements of the 20th century Lasers are basically excited light waves
BRIEF INTRODUCTIONABOUT LASER
A laser is a devicethatemits light througha process of optical amplification basedon the stimulatedemission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplificationby stimulated emission of radiation. Alaser differs from other sources of light in that it emits lightcoherently.
CHARACTERISTICS OF LASERLIGHT The combination of these three properties makes laser light focus 100 times better than ordinarylight
MetastableState 2.Thehigherstatemustbeametastablestate–astateinwhich theelectronsremainlongerthanusualsothatthetransitionto the lower state occurs by stimulated emission rather than spontaneously.Andthepopulationinversionoccur. E3 E3 E2 E2 Metastablestate Incidentphoton E2 E1 Photon ofenergy E1Emittedphoton E1 Metastablesystem Stimulatedemission
10 Incandescent vs. LaserLight Manywavelengths Multidirectional Incoherent Monochromatic Directional Coherent
ELECTROMAGNETICSPECTRUM Visible Radio GammaRayX-ray Ultraviolet Infrared Microwaves Radio ShortWavelength LongWavelength Lasers operateintheultraviolet,visible,andinfrared.
LASERSPECTRUM GammaRays X-Rays Ultra- Visible violet Infrared Micro- Radar waveswaves TV Radio waveswaves 10-1310-1210-1110-1010-910-810-710-610-510-410-310-210-1 1 10 102 Wavelength(m) LASERS Retinal HazardRegion Visible NearInfrared Ultraviolet FarInfrared 200300 400500600700800900100011001200130014001500 10600 Wavelength(nm) Communication Diode ArF 193 XeCl 308 HeNeRuby 633 694 CO2 10600 KrF 248 Ar 2488/515Nd:YA G 532 Alexandrite GaAs 755 905 Nd:YAG 1064 1550 Laser-Professionals.com
LASERCOMPONENTS ACTIVEMEDIUM Solid(Crystal) Gas Semiconductor(Diode) Liquid(Dye) OpticalResonator Output Beam Active Medium EXCITATION MECHANISM Optical Electrical Chemical High Reflectance Mirror(HR) Output Coupler Mirror(OC) Excitation Mechanism The Active Medium contains atoms which can emit lightby stimulatedemission. OPTICAL RESONATOR HR Mirror and OutputCoupler The Excitation Mechanism is a source of energy to excite the atoms to the proper energystate. The Optical Resonator reflects the laser beam through the active medium foramplification.
Thebeamoflightisreflectedbackandforthalongthe central tube, until the waves of light become coherent.
Mechanism of laseremission Absorption E1 E2
SpontaneousEmission & STIMULATED EMISSION
Classificationoflaseracc.Toproduction technique • Optically Pumped Solid-StateLasers • RubyLaser • Rare Earth IonLasers • Nd: YAGLasers. • Nd: GlassLasers • Tunable Solid-State lasers Liquid (Dye)Lasers GasLasers SemiconductorLasers Free ElectronLasers X-ray Lasers,and ChemicalLasers
Inmedicine tobreakupgallstonesandkidneystones, toweldbrokentissue(e.g.detachedretina) to destroy cancerous and precancerous cells; at thesametime,theheatsealoffcapillaries, toremoveplaqueclogginghumanarteries. usedtomeasurebloodcelldiameter Fiber-opticlaser catheterisinthetreatmentofbleeding ulcers. can photocoagulateblood canalsobeusedfordentaltreatment. USES ANDAPPLICATION
In industry to drill tinyholes in hardmaterials, forweldingandmachining, forliningupequipmentprecisely,especiallyin inaccessibleplaces
In everydaylife tobeusedasbar-codereaders, tobeusedincompactdiscplayers, to produce short pulses of light used in digital communications, toproduceholograms.
Holography Holography is the production of holograms by the use of laser. A hologram is a 3D image recorded in a special photographic plate. The image appears to float in space and to move when the viewer moves.
Research usedtomeasurethespeedoflightin alaboratory
Conclusion Laser communication in space has long been a goal for NASA because it would enable data transmission rates that are 10 to1,000 times higher than traditional radiowaves. While lasers and radio transmissions both travel at light-speed, lasers can pack more data. It's similar to moving from a dial-up Internet connection tobroadband. Astronomers could use lasers like very accurate rulers to measure the movement of planets with unprecedentedprecision. With microwaves, we're limited to numbers like a meter or two in distance, whereas [lasers have] a potential for getting down intowell beyond the centimeterrange.