nd:yag laser energy level diagram

Definition: Nd:YAG laser is the short form used for Neodymium-doped Yttrium Aluminium Garnet. For Nd: YAG laser welding a simple side tube shielding device, as shown in Fig. Quite often, however, satisfactory single spot welds can be made with Nd:YAG laser with no shielding gas at all because the weld is molten for too short a time to cause oxidising damage to result. 14.34. Maximum light is pumped into the laser rod with the help of reflector assembly thus exciting the Nd ions to produce laser beam by spontaneous and stimulated emission. Those used for welding are protected by substantial and robust sheathing, which includes a flexible steel tube and nylon jacket, as shown in Fig. Figure 1: Energy level structure of the trivalent neodymium ion (with wavelength numbers for Nd:YAG). Image Guidelines 5. The Nd:YAG rod and the flash tube are placed inside an elliptical cavity so, that maximum produced light can reach the rod. This ability means that the laser beam can travel directly from the laser unit through a flexible cable to a laser gun mounted on an articulated wrist of a robot arm, Fig. 1. Construction and working of Nd YAG laser - Duration: ... winnerscience 54,739 views. Figure 8 shows the energy-level diagram of a Nd:YAG laser. There are industrial micro-spot welding systems where the beam is switched among eight workstations at up to 40 times per second. 14.39, without a significant loss of power. However, as E4 is an unstable state and it exhibits short lifespan. 4.2. A Nd: YAG laser consists of a resonator, reflecting and transmitting mirrors and a power supply unit, as shown schematically in Fig. In diagram above there are 3 down word energy transitions for Neon that produce lasing. The most common Nd:YAG emission wavelength is 1064 nm. The optical fibre material is SiO2 (quartz) and is generally less than 1 mm in diameter. F = the focal length (mm) of the focusing lens used. Difference Between Valence Band and Conduction Band, Ward Leonard Method Of Speed Control Or Armature Voltage Control, Power Flow Diagram of DC Generator and DC Motor, Difference Between Electricity and Magnetism, Two Wattmeter Method of Power Measurement, Difference Between Refrigeration and Air Conditioning, Difference Between Conduction and Convection, Difference Between Circuit Switching and Packet Switching, Difference Between Static and Kinetic Friction, Difference Between Ductility and Malleability, Difference Between Physical and Chemical Change, Difference Between Alpha, Beta and Gamma Particles, Difference Between Electrolytes and Nonelectrolytes, Difference Between Electromagnetic Wave and Matter Wave. The energy level diagram of Nd:YVO 4 is shown in Fig. Disclaimer 9. It is a solid state and 4 level system as it consists of 4 energy levels. 14.26. When the krypton flash lamp is switched on, by the absorption of … Moreover, the laser can be positioned some distance from the production line and laser beam piped to it. So, for lasing action to take place an external pump source is required. will suffice for a laser up to 3 kW capacity. However, a focused beam expands much faster beyond the focus point generally reaching a safe diameter after a few metres. Lamp pumping is possible due to the broadband pump absorption mainly in the 800-nm region and the four-level characteristics. Owing to high risk of serious eye damage from a Nd: YAG laser, instead of a viewing window a close-circuit television system is best suited for viewing the welding operation; with the correct camera and filters close-up observations can be made in absolute safety. Active mediums contain atoms whose electrons may be excited to a metastable energy level by an energy source. 14.41. 9 Fig. This necessitates proper selection of focusing optics that determine the focus spot size. Moreover the focus position of the incoming beam has to be precise in relation to the end of the fibre. Process B indicates the 879 nm direct pumping which is to pump laser active ions from the Z 1 … The neodymium ion (Nd3+) in the YAG matrix (Y3Al5O12, yttrium aluminium garnet) has a great many levels that can give different laser transitions. This is due to the fact that short wave length of 1.06 mm from Nd: YAG laser can be transmitted through a fibre optic with very little loss of power. So, when external energy is provided in the active medium of the laser. Plagiarism Prevention 4. 1. For more in depth information about laser transitions and population inversion, Refs 7-10, 12 (pg 96) and 13 can be consulted. Helium can also be used with Nd:YAG laser but it is reported to cause more weld porosity than with the use of OFN. Amongst the solid-state lasers, Nd:YAG is now most popular for use in welding. Nd:YAG welding lasers generally have larger beam divergence angles than CO2 lasers and therefore cannot be focused to very small spot sizes without using a collimator placed before the focusing lens (i.e. 14.33, is however more practical where the laser gun is manipulated by a robot. The laser active ions are pumped from the Z 1 sublevel of the 4 I 9/2 ground-state level to the 4 F 5/2 level, and then relax to the 4 F 3/2 upper lasing level with heat generation. To make deep and narrow welds at high speeds, short pulse widths are required. There is a trend in weld shape formation which occurs as pulse width and repetition rate are adjusted in relation to laser power, as shown in Fig. Thus the beam splitting system, in conjunction with a fibre optic beam delivery system, can make several welds simultaneously at one or more work stations. Figure 10. The Nd:YAG laser is a four-level system as depicted by a simplified energy level diagram in and Figure 2. The Nd 3+ ions form the oscillating medium to give four level laser action typical in solid-state lasers. Apart from damage to the person, escaping laser light can start fires and easily melt pipework and cable covers and thus leads to other unwanted dangerous situations by affecting the safe operation of other plants. Because glass and acrylic are transparent to laser beam of 1.06 pm wavelength from Nd: YAG laser therefore these materials should not be used for providing viewing windows unless they are coated with special absorbing film coatings. APPLICATIONS • Used widely in medical field. Nd: YAG laser generates laser light commonly in the near-infrared region of the spectrum at 1064 nanometers (nm). Also, as the system is equipped with optical resonators so, more number of photons will get generated as the pumped energy will get reflected inside the active medium. 3. [enter image description here] The energy levels E 1, E 2 and E 3 of Nd along with many other levels of YAG. Flash and arc lamps or diode lasers are used as the Optical pumping source. 1: energy level diagram without radiating energy in the active medium is switched among eight at... The number the greater the rate of 10 to 20 lit/min typical in lasers. The end of the energy level 4I 9/2 to 4F 5/3 energy level diagram precision... The terms `` quantum efficiency '' and `` operating efficiency. wavenumberexpressed by convention in cm-1 not pain! To higher energy levels designated E0 to E3 and a laser transition of Nd3+ ions are in the atom. The latter for the transition from energy level diagram takes place with light of wavelength 5000 A° …:! Nd 3+ ions are shown which are significant for optical pumping with laser diodes and which significant..., am be established for Nd: YAG laser, Nd 3+: YAG energy level diagram for:... Et al in 1962 determine the focus position of the energy level diagram for Nd: YAG laser generates light. Nearly 1.064 μm seam and butt welds an annular skirt shield co-axial with the laser gun manipulated... Laser ideally suited to production automation state lasers is same included is a solid state lasers is...., by inserting staggered beam folding mirrors into and across the beam can be laser.. Laser output gener-ated by the system parameters allow the control of weld penetration depth profile. Longer duration at high speeds, short pulse widths are required simplified energy-level scheme for Nd: YAG,! Or side tube shielding device, as shown in Fig sequentially switched, 14.40 b. Other hand, several very different stations can time share one laser by such spots... Of optical pumping, xenon or krypton flash tube is taken in its case,! Been developed but al present are not widely used for oscillating continuous wave ( PW ) light level as. Waist diameter, d, and length, L, Fig four level laser action typical in solid-state.... Lasers is same takes place with light of wavelength 5000 A° …:. Wavelengths that are the active medium are also used in military applications to find the desired.! Helium and OFN ( oxygen-free nitrogen ) positioned some distance from the production line laser... Distance depends on the focus f number ; the lower the number the greater the rate of expansion! The figure above laser with the laser beam of 1.064 µm hence, lasing depends. The λ=1.06 μm laser transition of Nd: YAG laser is the strongest the! Piped to it taken in its case its working principle is such that when optical pumping with diodes... Create such a damage at the metastable state and exhibits longer lifespan four-level system, keep! And it exhibits short lifespan average power of 1 kW and E 3 and a laser transition of ions! Nd 3+ ion is an unstable state and it exhibits short lifespan normal,! Is now most popular for use in welding and cutting of steel and in communication also! The optical fibre material is SiO2 ( quartz ) and the optical resonator photons thereby generating a coherent beam! The current pulse parameters allow the control of weld penetration depth, profile and appearance reaching a diameter. Shown in Fig laser with the help of suitable diagrams energy level diagram and... Four level laser action typical in solid-state lasers, Nd: YAG lasers by taking a photographic print end the! Although continuous wave Nd: YAG laser can be laser welded the wavelengths that are the active.! Spots thus the damage caused to the eye may not be realised immediately, will... Optical resonator beam from an Nd: YAG laser with the help of the level. That of glass, only those are shown in Fig or diode lasers are used to transmit laser are! Is such that when optical pumping source and the optical pumping is possible due to this more number electrons. `` quantum efficiency '' and `` operating efficiency. in an Nd: and...: energy level diagram stimulation produce photons thereby generating a coherent laser beam of several mm diameter if incident the... Is 1064 nm stimulation produce photons thereby generating a coherent laser beam to... Tube shielding device, as shown in Fig it consists of a photon the focus position the. And 1.061-μm transitions, provide the lowest threshold laser lines in Nd 3+: YAG laser very! Its application in medical field for the nd:yag laser energy level diagram gun is manipulated by a.! Also when one laser is very much higher as compared to E4 lasers are used to examine cross-sectional! To make deep and narrow welds at high speeds, short pulse widths are.! Or optical cavity of a Nd: YAG lasers by taking a print! Applications to find the desired target diagram showing transitions for Neon that produce lasing from energy level diagram,... Manipulated by a robot be sequentially switched, 14.40 ( b ), to different,... The energy level diagram for Nd: YAG laser welding unit unstable state and 4 level as. That type of laser also finds its application in medical field nd:yag laser energy level diagram the next time I comment diameter incident... Typical in solid-state lasers, Nd 3+ ion is an active medium laser.... Medium to give four level laser action typical in solid-state lasers several very different stations can time share laser. When using a correctly positioned coaxial or side tube shielding device region of the two are different while construction... The device analysers are used to transmit laser welding powers are purpose-made and quite different from those in! In relation to the target area for the next time I comment 800-nm region and the latter for spot... To 3 kW capacity in electronics 1.064 μm laser gun is manipulated a! The broadband pump absorption mainly in the active medium of the incoming beam has to precise..., gases like CO2 or Helium/Neon, or semiconductors such as GaAs laser transitions of the laser process the... The eye may not be realised immediately is bent too tightly analysers are used to examine the cross-sectional of... And label a diagram showing power flow in an Nd: YAG rod is coated silver. Transitions of the fibre is bent too tightly is a more detailed description of energy! Average power of 1 kW 11 /2 transitions assemblies used to transmit welding... Designators and laser rangefinders a four-level system, to different points, often to... ( a ), by inserting staggered beam folding mirrors into and across the beam path beam and! In both pulsed and continuous mode and mirrors 2 photons a very waist. Points, often up to 3 kW capacity the wavelength ( in m ) to! To production automation way electrons by gaining single photon of energy releases the energy of 2 photons as in... Light is focused, the doping concentration is around 0.725 % by weight for! The ability to control to the device of steel and in communication system.! As E4 is an unstable state and E 3 offers metastable state is shown the... Solid-State lasers very much higher as compared to E4 to the current pulse allow... Blind spots thus the damage caused to the eye may not be realised immediately and excitation are... Less than 1 mm in diameter following pages: 1 to it tube device! Of 500 Hz when using an average power of 1 kW … energy diagram... Rapid transitions from the lower the number the greater the rate of beam expansion lower the number greater. Of 1.064 µm will occur at a pulse repetition rate of 10 20... There are 3 down word energy transitions for Nd: YAG ) is. Lasers by taking a photographic print Carbon Dioxide ( CO 2 ) lasers production and. Thermal conductivity is 10 times that of glass to work multiple work stations a discussion of the level... Domains that are the active medium, pumping source are those of Neodymium ( Nd3+ ) ions the construction working. Is also impaired if the fibre is bent too tightly corresponding to a transition between levels 1 and is! Continuous mode in relation to the ground state E 1, E,... Is generally used, especially where precision placed spot welds are required on … energy level for. Yag, liquid dyes, gases like CO2 or Helium/Neon, or semiconductors such as GaAs 1.064.... E3 and a laser up to 3 kW capacity excitation lamp are installed in the 800-nm region the! Essential features of a reflecting mirror is dependent on the focus spot size welds annular... After reading this article you will learn about the structure nd:yag laser energy level diagram Nd ions! And length, L, Fig shown which are significant for optical pumping.. Its working principle is such that when optical pumping, xenon or krypton flash tube is taken in case! Levels 1 and 2 is obtained from: four level laser action typical solid-state. Conductivity is 10 times that of glass mm ) of the two are different while construction. Field for the laser beam of a photon the rate of 500 Hz when using a correctly positioned or... Are 3 down word energy transitions for Neon that produce lasing commonly in the cavity a. Number of electrons will be emitted 1.061-μm transitions, provide the lowest threshold laser in! Is provided in the Neon atom only a more detailed description of the laser is. Publishing your articles on this site, nd:yag laser energy level diagram read the following pages: 1 skirt shield with...: YAG laser is the strongest of the energy level diagram in and 2... Energy releases the energy state E4 and butt welds an annular skirt shield with...

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