Book contents
- Frontmatter
- Contents
- Preface to the Second Edition
- 1 Electromagnetic waves, light, and lasers
- 2 Optical frequency amplifiers
- 3 An introduction to two practical laser systems
- 4 Optical resonators containing amplifying media
- 5 Laser radiation
- 6 Control of laser oscillators
- 7 Optically pumped solid-state lasers
- 8 Gas lasers
- 9 Molecular gas lasers I
- 10 Molecular gas lasers II
- 11 Tunable lasers
- 12 Semiconductor lasers
- 13 Passive optical systems
- 14 Periodic optical systems, resonators, and inhomogeneous media
- 15 The optics of Gaussian beams
- 16 Optical fibers and waveguides
- 17 The optics of anisotropic media
- 18 The electro-optic and acousto-optic effects and modulation of light beams
- 19 Introduction to nonlinear processes
- 20 Wave propagation in nonlinear media
- 21 Detection of optical radiation
- 22 Coherence theory
- 23 Laser applications
- Appendix 1 Optical terminology
- Appendix 2 The ´-function
- Appendix 3 Black-body radiation formulas
- Appendix 4 RLC circuits
- Appendix 5 Storage and transport of energy by electromagnetic fields
- Appendix 6 The reflection and refraction of a plane electromagnetic wave at a boundary between two isotropicmedia of different refractive indices
- Appendix 7 The vector differential equation for light rays
- Appendix 8 Symmetry properties of crystals and the 32 crystal classes
- Appendix 9 Tensors
- Appendix 10 Bessel-function relations
- Appendix 11 Green's functions
- Appendix 12 Recommended values of some physical constants
- Index
- References
3 - An introduction to two practical laser systems
Published online by Cambridge University Press: 05 June 2014
- Frontmatter
- Contents
- Preface to the Second Edition
- 1 Electromagnetic waves, light, and lasers
- 2 Optical frequency amplifiers
- 3 An introduction to two practical laser systems
- 4 Optical resonators containing amplifying media
- 5 Laser radiation
- 6 Control of laser oscillators
- 7 Optically pumped solid-state lasers
- 8 Gas lasers
- 9 Molecular gas lasers I
- 10 Molecular gas lasers II
- 11 Tunable lasers
- 12 Semiconductor lasers
- 13 Passive optical systems
- 14 Periodic optical systems, resonators, and inhomogeneous media
- 15 The optics of Gaussian beams
- 16 Optical fibers and waveguides
- 17 The optics of anisotropic media
- 18 The electro-optic and acousto-optic effects and modulation of light beams
- 19 Introduction to nonlinear processes
- 20 Wave propagation in nonlinear media
- 21 Detection of optical radiation
- 22 Coherence theory
- 23 Laser applications
- Appendix 1 Optical terminology
- Appendix 2 The ´-function
- Appendix 3 Black-body radiation formulas
- Appendix 4 RLC circuits
- Appendix 5 Storage and transport of energy by electromagnetic fields
- Appendix 6 The reflection and refraction of a plane electromagnetic wave at a boundary between two isotropicmedia of different refractive indices
- Appendix 7 The vector differential equation for light rays
- Appendix 8 Symmetry properties of crystals and the 32 crystal classes
- Appendix 9 Tensors
- Appendix 10 Bessel-function relations
- Appendix 11 Green's functions
- Appendix 12 Recommended values of some physical constants
- Index
- References
Summary
Introduction
To give a little more practical emphasis to some of the ideas we have dealt with so far, let us consider some of the details of the two laser systems in which population inversion and laser oscillation were first demonstrated. One of these lasers uses an amplifying medium that is a crystalline solid – the ruby laser; in the other the amplifying medium is a gas – a mixture of helium and neon. In each case, the amplifying medium is pumped into a state of population inversion by feeding energy into it in an appropriate way. Laser oscillation occurs when the amplifying medium is placed between a pair of suitable aligned mirrors that provide the necessary optical feedback to cause oscillation to occur. The ruby laser was the first operational laser, being demonstrated on May 16, 1960 by Theodore Maiman of the Hughes Aircraft Company in Malibu, California [1].
That the ruby laser was the first laser to be demonstrated surprised many in the scientific community. This is because the ruby laser is a three-level laser, which was expected to be much more difficult to operate than a four-level laser. This is an important distinction, which we will examine before describing the first two lasers in detail.
Three- and four-level lasers
The distinction between three- and four-level lasers can be illustrtated with the aid of Fig. 3.2. Energy is fed into the system to move particles from the ground state, level 0, to a pumping energy level, level 3.
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- Lasers and Electro-opticsFundamentals and Engineering, pp. 72 - 84Publisher: Cambridge University PressPrint publication year: 2014