Laser sources-lasers with solid state lasing mediums, Mechanical Engineering

Assignment Help:

Lasers with Solid State Lasing Mediums

For an active medium, the solid state laser uses lasing ions which are suspended in a rod shaped solid matrix. These "dopants" in the rod are excited by a source of intense light. This may be either one or two cylindrical flash lamps or a helical flash lamp which surrounds the rod. If two cylindrical flash lamps are used, the laser rod is placed between them at the common focus of two ellipses whose other foci determine the placement of the flash lamps.

The distance between foci, in each of the two ellipses, sharing a common focus, is defined by the configuration of an elliptical reflector that surrounds the excitation sources and the laser rod. The arrangement provides an efficient coupling of excitation light into the lasing medium. A water cooling syst em controls the temperature of the rod and flash lamps.

Three major representatives of this type of laser are made of synthetic ruby, of neodymium; glass (Nd: Glass), and Neodymium Doped Yttrium Aluminium Garnet (Nd:YAG). In each of these materials, lasing ions exist as minority dopants in the host matrix. For all the three, flash lamp Nlife is limited and operating costs are higher than for CO2 lasers, but certain advantages remain. Solid state lasers can be operated in several ways. One way is the excitation of the lasing medium (rod) with capacitate discharge through the flash lamp(s), which results in the emission of a brief flash of light. This in turn excites the lasing medium into emitting a burst of light. For Nd:YAG this occurs at a wavelength of 1.064 m. Using this excitation scheme allows pulses that lie between 0.2 and 12.0 milliseconds, at repetition rates up to 100 pulses per second. At slower rates, the TEM multimode energy in each output pulse may be 20 joules or more for a typical commercially available laser; while at the most rapid rates, this will fall to approximately 2 joules per pulse.

Even at the highest repetition rates, the energy in each pulse is sufficient for drilling and spot welding metals. Since, the wavelength of light emitted by a Nd:YAG laser is relatively short, the output beam can be focused to a spot of small diameter. These flash lamp pumped lasers are capable of drilling holes as small as 0.025 mm in diameter, but they are not well suited for drilling large holes because of the non uniform distribution of energy across the output beam.


Related Discussions:- Laser sources-lasers with solid state lasing mediums

Wave motion, Wave motion takes place all throughout nature, from the waves...

Wave motion takes place all throughout nature, from the waves of the ocean to the electromagnetic waves that comprise visible light. Though different types of waves involve differe

Determine the loss in fuel cost per hour, Give a neat and clean diagram of ...

Give a neat and clean diagram of Heavy water type "CANDU" nuclear power plant and illustrate its working. The incremental fuel costs for two generating units ‘a and b' of a powe

Calculate the magnitude of maximum bending moment, Calculate the magnitude ...

Calculate the magnitude of maximum bending moment: The shear force diagram for the overhanging beam is illustrated in Figure. Draw the loading diagram & bending moment diagram

Shipping of steel pipes, Q. Shipping of steel pipes? Pipe will be trans...

Q. Shipping of steel pipes? Pipe will be transported from the coating yard to the job site as specified in the Purchaser Order. The Applicator will ensure that the pipe has suf

Explain the intensive properties of a system, Explain the Intensive Propert...

Explain the Intensive Properties of a System Intensive properties are those, which have similar value for any part of the system or the properties which are independent of the

Section modulus, Section modulus: Define the Section modulus. What d...

Section modulus: Define the Section modulus. What do you mean by torsional section modulus or polar modulus?  The moment of inertia of plane about the axis perpendicula

AOC, The objective of the project is to protect damage of the DC motors. If...

The objective of the project is to protect damage of the DC motors. If the motor is not working it will be shown with red light, if working normally then green and if working at a

Calculate the shear stress , A hollow circular shaft has an internal diamet...

A hollow circular shaft has an internal diameter of 48 mm and an external diameter of 54 mm. Calculate the shear stress produced at the outer and inner surfaces of the shaft when t

Road under special conditions, Road under Special Conditions: Roads pa...

Road under Special Conditions: Roads passing through difficult terrain and environmental conditions require special attention in design, construction and maintenance. The foll

Shock absorbers, how bike''s hydraulic shock absorbers work?

how bike''s hydraulic shock absorbers work?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd