Principles of Lasers

by Svelto, Orazio; Hanna, David C.

• ISBN13: 9780306457487
• ISBN10: 0306457482
• Edition: 4th
• Format: Hardcover
• Copyright: 1998-04-01
• Publisher: Kluwer Academic Pub

Summary

This new Fourth Edition of Principles of Lasers is so thoroughly updated and expanded that it is virtually a whole new book. But the text's essential mission remains the same: to provide a wide-ranging yet unified description of laser behavior, physics, technology, and current applications. Dr. Svelto emphasizes the physical rather than the mathematical aspects of lasers, and presents the subject in the simplest terms compatible with a correct physical understanding. Praise for earlier editions:"Professor Svelto is himself a longtime laser pioneer and his text shows the breadth of his broad acquaintance with all aspects of the field ... Anyone mastering the contents of this book will be well prepared to understand advanced treatises and research papers in laser science and technology." (Arthur L. Schawlow, 1981 Nobel Laureate in Physics)"Already well established as a self-contained introduction to the physics and technology of lasers ... Professor Svelto's book, in this lucid translation by David Hanna, can be strongly recommended for self-study or teaching at the final-year undergraduate or first-year post-graduate levels." (Physics Bulletin)"A thorough understanding of this book in conjunction with one of the existing volumes on laser safety will go a long way in providing the health physicist with the understanding he needs ... Highly recommended." (Health Physics)"Introduces laser science and technology with the accessibility appropriate for the nonspecialist and the enthusiasm of the pioneer." (Laser Focus)"A very good introduction to laser theory and practice ... aimed at upper-level undergraduate students. It is logically organized and easy to read ... Most of the basic mathematical framework needed to understand this evolving field is presented. Every chapter contains a good set of problems, answers to some of which are given in the back." (Sci-Tech News) Orazio Svelto is Professor of Quantum Electronics at the Polytechnic Institute of Milan and Director of the Quantum Electronics Center of the Italian National Research Council. His research has covered a wide range of activity in the field of laser physics and quantum electronics, starting from the very beginning of these disciplines. This activity includes ultrashort-pulse generation and applications, development of laser resonators and mode-selection techniques, laser applications in biology and medicine, and development of solid-state lasers. Professor Svelto is the author of more than 150 scientific papers and his researches have been the subject of more than 50 invited papers and international conferences. He has served as a program chair of the IX International Quantum Electronics Conference (1976), as a chair of the European program committee for CLEO '85 and CLEO '90, and he was general co-chair for the first CLEO-Europe Conference (1994). He is an elected member of the Italian "Accademia dei XL" and a Fellow of the IEEE.

Author Biography

Orazio Svelto is Professor of Quantum Electronics at the Polytechnic Institute of Milan and Director of the Quantum Electronics Center of the Italian National Research Council. His research has covered a wide range of activity in the field of laser physics and quantum electronics, starting from the very beginning of these disciplines. This activity includes ultrashort-pulse generation and applications, development of laser resonators and mode-selection techniques, laser applications in biology and medicine, and development of solid-state lasers. Professor Svelto is the author of more than 150 scientific papers and his researches have been the subject of more than 50 invited papers and international conferences. He has served as a program chair of the IX International Quantum Electronics Conference (1976), as a chair of the European program committee for CLEO '85 and CLEO '90, and he was general co-chair for the first CLEO-Europe Conference (1994). He is an elected member of the Italian "Accademia dei XL" and a Fellow of the IEEE.

Table of Contents

List of Examples	xix
1. Introductory Concepts	1	(16)
1.1. Spontaneous and Stimulated Emission, Absorption	2	(2)
1.2. The Laser Idea	4	(3)
1.3. Pumping Schemes	7	(2)
1.4. Properties of Laser Beams	9	(5)
1.4.1. Monochromaticity	9	(1)
1.4.2. Coherence	9	(1)
1.4.3. Directionality	10	(1)
1.4.4. Brightness	11	(2)
1.4.5. Short Pulse Duration	13	(1)
1.5. Laser Types	14	(1)
Problems	14	(3)
2. Interaction of Radiation with Atoms and Ions	17	(64)
2.1. Introduction	17	(1)
2.2. Summary of Blackbody Radiation Theory	17	(8)
2.2.1. Modes of a Rectangular Cavity	19	(3)
2.2.2. Rayleigh-Jeans and Planck Radiation Formula	22	(1)
2.2.3. Planck's Hypothesis and Field Quantization	23	(2)
2.3. Spontaneous Emission	25	(7)
2.3.1. Semiclassical Approach	26	(3)
2.3.2. Quantum Electrodynamics Approach	29	(2)
2.3.3. Allowed and Forbidden Transitions	31	(1)
2.4. Absorption and Stimulated Emission	32	(11)
2.4.1. Absorption and Stimulated Emission Rates	32	(4)
2.4.2. Allowed and Forbidden Transitions	36	(1)
2.4.3. Transition Cross Section, Absorption, and Gain Coefficient	37	(5)
2.4.4. Einstein Thermodynamic Treatment	42	(1)
2.5. Line-Broadening Mechanisms	43	(7)
2.5.1. Homogeneous Broadening	44	(4)
2.5.2. Inhomogeneous Broadening	48	(1)
2.5.3. Concluding Remarks	49	(1)
2.6. Nonradiative Decay and Energy Transfer	50	(8)
2.6.1. Mechanisms of Nonradiative Decay	50	(6)
2.6.2. Combined Effects of Radiative and Nonradiative Processes	56	(2)
2.7. Degenerate or Strongly Coupled Levels	58	(6)
2.7.1. Degenerate Levels	58	(2)
2.7.2. Strongly Coupled Levels	60	(4)
2.8. Saturation	64	(7)
2.8.1. Saturation of Absorption: Homogeneous Line	64	(4)
2.8.2. Gain Saturation: Homogeneous Line	68	(1)
2.8.3. Inhomogeneously Broadened Line	69	(2)
2.9. Fluourescence Decay of an Optically Dense Medium	71	(5)
2.9.1. Radiation Trapping	71	(1)
2.9.2. Amplified Spontaneous Emission	71	(5)
2.10. Concluding Remarks	76	(1)
Problems	77	(1)
References	78	(3)
3. Energy Levels, Radiative, and Nonradiative Transitions in Molecules and Semiconductors	81	(48)
3.1. Molecules	81	(11)
3.1.1. Energy Levels	81	(4)
3.1.2. Level Occupation at Thermal Equilibrium	85	(2)
3.1.3. Stimulated Transitions	87	(4)
3.1.4. Radiative and Nonradiative Decay	91	(1)
3.2. Bulk Semiconductors	92	(20)
3.2.1. Electronic States	92	(4)
3.2.2. Density of States	96	(1)
3.2.3. Level Occupation at Thermal Equilibrium	97	(4)
3.2.4. Stimulated Transitions: Selection Rules	101	(2)
3.2.5. Absorption and Gain Coefficients	103	(6)
3.2.6. Spontaneous Emission and Nonradiative Decay	109	(2)
3.2.7. Concluding Remarks	111	(1)
3.3. Semiconductor Quantum Wells	112	(13)
3.3.1. Electronic States	112	(3)
3.3.2. Density of States	115	(2)
3.3.3. Level Occupation at Thermal Equilibrium	117	(1)
3.3.4. Stimulated Transitions: Selection Rules	118	(2)
3.3.5. Absorption and Gain Coefficients	120	(3)
3.3.6. Strained Quantum Wells	123	(2)
3.4. Quantum Wires and Quantum Dots	125	(1)
3.5. Concluding Remarks	126	(1)
Problems	127	(1)
References	128	(1)
4. Ray and Wave Propagation through Optical Media	129	(32)
4.1. Introduction	129	(1)
4.2. Matrix Formulation of Geometric Optics	129	(6)
4.3. Wave Reflection and Transmission at a Dielectric Interface	135	(2)
4.4. Multilayer Dielectric Coatings	137	(3)
4.5. Fabry-Perot Interferometer	140	(5)
4.5.1. Properties of a Fabry-Perot Interferometer	140	(4)
4.5.2. Fabry-Perot Interferometer as a Spectrometer	144	(1)
4.6. Diffraction Optics in the Paraxial Approximation	145	(3)
4.7. Gaussian Beams	148	(10)
4.7.1. Lowest Order Mode	148	(3)
4.7.2. Free-Space Propagation	151	(3)
4.7.3. Gaussian Beams and ABCD Law	154	(1)
4.7.4. Higher Order Modes	155	(3)
4.8. Conclusions	158	(1)
Problems	158	(2)
References	160	(1)
5. Passive Optical Resonators	161	(40)
5.1. Introduction	161	(4)
5.1.1. Plane Parallel (Fabry-Perot) Resonator	162	(1)
5.1.2. Concentric (Spherical) Resonator	163	(1)
5.1.3. Confocal Resonator	163	(1)
5.1.4. Generalized Spherical Resonator	163	(1)
5.1.5. Ring Resonator	164	(1)
5.2. Eigenmodes and Eigenvalues	165	(2)
5.3. Photon Lifetime and Cavity Q	167	(2)
5.4. Stability Condition	169	(4)
5.5. Stable Resonators	173	(14)
5.5.1. Resonators with Infinite Aperture	173	(1)
5.5.1.1. Eigenmodes	174	(4)
5.5.1.2. Eigenvalues	178	(2)
5.5.1.3. Standing and Traveling Waves in a Two-Mirror Resonator	180	(1)
5.5.2. Effects of a Finite Aperture	181	(3)
5.5.3. Dynamically and Mechanically Stable Resonators	184	(3)
5.6. Unstable Resonators	187	(11)
5.6.1. Geometric Optics Description	188	(2)
5.6.2. Wave Optics Description	190	(3)
5.6.3. Advantages and Disadvantages of Hard-Edge Unstable Resonators	193	(1)
5.6.4. Unstable Resonators with Variable-Reflectivity Mirrors	194	(4)
5.7. Concluding Remarks	198	(1)
Problems	198	(2)
References	200	(1)
6. Pumping Processes	201	(48)
6.1. Introduction	201	(3)
6.2. Optical Pumping by an Incoherent Light Source	204	(6)
6.2.1. Pumping Systems	204	(2)
6.2.2. Pump Light Absorption	206	(2)
6.2.3. Pump Efficiency and Pump Rate	208	(2)
6.3. Laser Pumping	210	(18)
6.3.1. Laser-Diode Pumps	212	(2)
6.3.2. Pump Transfer Systems	214	(1)
6.3.2.1. Longitudinal Pumping	214	(5)
6.3.2.2. Transverse Pumping	219	(2)
6.3.3. Pump Rate and Pump Efficiency	221	(2)
6.3.4. Threshold Pump Power for Four-Level and Quasi-Three-Level Lasers	223	(3)
6.3.5. Comparison between Diode Pumping and Lamp Pumping	226	(2)
6.4. Electrical Pumping	228	(16)
6.4.1. Electron Impact Excitation	231	(1)
6.4.1.1. Electron Impact Cross Section	232	(3)
6.4.2. Thermal and Drift Velocities	235	(2)
6.4.3. Electron Energy Distribution	237	(3)
6.4.4. Ionization Balance Equation	240	(1)
6.4.5. Scaling Laws for Electrical Discharge Lasers	241	(1)
6.4.6. Pump Rate and Pump Efficiency	242	(2)
6.5. Conclusions	244	(1)
Problems	244	(3)
References	247	(2)
7. Continuous Wave Laser Behavior	249	(56)
7.1. Introduction	249	(1)
7.2. Rate Equations	249	(9)
7.2.1. Four-Level Laser	250	(5)
7.2.2. Quasi-Three-Level Laser	255	(3)
7.3. Threshold Conditions and Output Power: Four-Level Laser	258	(15)
7.3.1. Space-Independent Model	258	(7)
7.3.2. Space-Dependent Model	265	(8)
7.4. Threshold Condition and Output Power: Quasi-Three-Level Laser	273	(4)
7.4.1. Space-Independent Model	273	(1)
7.4.2. Space-Dependent Model	274	(3)
7.5. Optimum Output Coupling	277	(2)
7.6. Laser Tuning	279	(2)
7.7. Reasons for Multimode Oscillation	281	(3)
7.8. Single-Mode Selection	284	(7)
7.8.1. Single-Transverse-Mode Selection	284	(1)
7.8.2. Single-Longitudinal-Mode Selection	285	(1)
7.8.2.1. Fabry-Perot Etalons as Mode-Selective Elements	285	(3)
7.8.2.2. Single-Mode Selection in Unidirectional Ring Resonators	288	(3)
7.9. Frequency Pulling and Limit to Monochromaticity	291	(2)
7.10. Laser Frequency Fluctuations and Frequency Stabilization	293	(4)
7.11. Intensity Noise and Intensity Noise Reduction	297	(3)
7.12. Conclusions	300	(1)
Problems	301	(2)
References	303	(2)
8. Transient Laser Behavior	305	(60)
8.1. Introduction	305	(1)
8.2. Relaxation Oscillations	305	(5)
8.3. Dynamic Instabilities and Pulsations in Lasers	310	(1)
8.4. Q-Switching	311	(18)
8.4.1. Dynamics of the Q-Switching Process	311	(2)
8.4.2. Q-Switching Methods	313	(1)
8.4.2.1. Electrooptical Q-Switching	313	(2)
8.4.2.2. Rotating Prisms	315	(1)
8.4.2.3. Acoustooptic Q-Switches	316	(1)
8.4.2.4. Saturable Absorber Q-Switch	317	(2)
8.4.3. Operating Regimes	319	(2)
8.4.4. Theory of Active Q-Switching	321	(8)
8.5. Gain Switching	329	(1)
8.6. Mode Locking	330	(29)
8.6.1. Frequency-Domain Description	331	(5)
8.6.2. Time-Domain Picture	336	(1)
8.6.3. Mode-Locking Methods	337	(1)
8.6.3.1. Active Mode Locking	337	(5)
8.6.3.2. Passive Mode Locking	342	(5)
8.6.4. Role of Cavity Dispersion in Femtosecond Mode-Locked Lasers	347	(1)
8.6.4.1. Phase Velocity, Group Velocity, and Group-Delay Dispersion	347	(3)
8.6.4.2. Limitation on Pulse Duration Due to Group-Delay Dispersion	350	(1)
8.6.4.3. Dispersion Compensation	351	(2)
8.6.4.4. Soliton-Type Mode Locking	353	(2)
8.6.5. Mode-Locking Regimes and Mode-Locking System	355	(4)
8.7. Cavity Dumping	359	(2)
8.8. Concluding Remarks	361	(1)
Problems	361	(2)
References	363	(2)
9. Solid-State, Dye, and Semiconductor Lasers	365	(54)
9.1. Introduction	365	(1)
9.2. Solid-State Lasers	365	(21)
9.2.1. Ruby Laser	367	(3)
9.2.2. Neodymium Lasers	370	(1)
9.2.2.1. Nd:YAG Laser	370	(3)
9.2.2.2. Nd:Glass Laser	373	(1)
9.2.2.3. Other Crystalline Hosts	373	(1)
9.2.3. Yb:YAG Laser	374	(2)
9.2.4. Er: YAG and Yb:Er:Glass Lasers	376	(1)
9.2.5. Tm:Ho:YAG Laser	377	(1)
9.2.6. Fiber Lasers	378	(3)
9.2.7. Alexandrite Laser	381	(2)
9.2.8. Titanium Sapphire Laser	383	(2)
9.2.9. Cr:LiSAF and Cr:LiCAF Lasers	385	(1)
9.3. Dye Lasers	386	(8)
9.3.1. Photophysical Properties of Organic Dyes	387	(4)
9.3.2. Characteristics of Dye Lasers	391	(3)
9.4. Semiconductor Lasers	394	(21)
9.4.1. Principle of Semiconductor Laser Operation	394	(2)
9.4.2. Homojunction Lasers	396	(2)
9.4.3. Double-Heterostructure Lasers	398	(4)
9.4.4. Quantum Well Lasers	402	(3)
9.4.5. Laser Devices and Performances	405	(3)
9.4.6. Distributed Feedback and Distributed Bragg Reflector Lasers	408	(3)
9.4.7. Vertical-Cavity Surface-Emitting Lasers	411	(2)
9.4.8. Semiconductor Laser Applications	413	(2)
9.5. Conclusions	415	(1)
Problems	415	(2)
References	417	(2)
10. Gas, Chemical, Free-Electon, and X-Ray Lasers	419	(44)
10.1. Introduction	419	(1)
10.2. Gas Lasers	419	(29)
10.2.1. Neutral Atom Lasers	420	(1)
10.2.1.1. Helium Neon Laser	420	(5)
10.2.1.2. Copper Vapor Laser	425	(2)
10.2.2. Ion Lasers	427	(1)
10.2.2.1. Argon Laser	427	(3)
10.2.2.2. He-Cd Laser	430	(2)
10.2.3. Molecular Gas Lasers	432	(1)
10.2.3.1. CO2 Laser	432	(10)
10.2.3.2. CO Laser	442	(2)
10.2.3.3. Nitrogen Laser	444	(1)
10.2.3.4. Excimer Lasers	445	(3)
10.3. Chemical Lasers	448	(4)
10.4. Free-Electron Lasers	452	(4)
10.5. X-Ray Lasers	456	(2)
10.6. Concluding Remarks	458	(1)
Problems	459	(1)
References	460	(3)
11. Properties of Laser Beams	463	(30)
11.1. Introduction	463	(1)
11.2. Monochromaticity	463	(1)
11.3. First-Order Coherence	464	(12)
11.3.1. Degree of Spatial and Temporal Coherence	464	(4)
11.3.2. Measurement of Spatial and Temporal Coherence	468	(3)
11.3.3. Relation between Temporal Coherence and Monochromaticity	471	(2)
11.3.4. Nonstationary Beams	473	(1)
11.3.5. Spatial and Temporal Coherence of Single-Mode and Multimode Lasers	473	(2)
11.3.6. Spatial and Temporal Coherence of a Thermal Light Source	475	(1)
11.4. Directionality	476	(7)
11.4.1. Beams with Perfect Spatial Coherence	477	(2)
11.4.2. Beams with Partial Spatial Coherence	479	(1)
11.4.3. The M^2 Factor and the Spot Size Parameter of a Multimode Laser Beam	480	(3)
11.5. Laser Speckle	483	(3)
11.6. Brightness	486	(1)
11.7. Statistical Properties of Laser Light and Thermal Light	487	(2)
11.8. Comparison between Laser Light and Thermal Light	489	(2)
Problems	491	(1)
References	492	(1)
12. Laser Beam Transformation: Propagation, Amplification, Frequency Conversion, Pulse Compression, and Pulse Expansion	493	(42)
12.1. Introduction	493	(1)
12.2. Spatial Transformation: Propagation of a Multimode Laser Beam	494	(1)
12.3. Amplitude Transformation: Laser Amplification	495	(9)
12.3.1. Examples of Laser Amplifiers: Chirped-Pulse-Amplification	500	(4)
12.4. Frequency Conversion: Second-Harmonic Generation and Parametric Oscillation	504	(19)
12.4.1. Physical Picture	504	(1)
12.4.1.1. Second Harmonic Generation	505	(7)
12.4.1.2. Parametric Oscillation	512	(2)
12.4.2. Analytical Treatment	514	(2)
12.4.2.1. Parametric Oscillation	516	(4)
12.4.2.2. Second-Harmonic Generation	520	(3)
12.5. Transformation in Time	523	(7)
12.5.1. Pulse Compression	524	(5)
12.5.2. Pulse Expansion	529	(1)
Problems	530	(2)
References	532	(3)
Appendixes	535	(48)
A. Semiclassical Treatment of the Interaction of Radiation and Matter	535	(6)
B. Lineshape Calculation for Collision Broadening	541	(4)
C. Simplified Treatment of Amplified Spontaneous Emission	545	(4)
References	548	(1)
D. Calculation of the Radiative Transition Rates of Molecular Transitions	549	(4)
E. Space-Dependent Rate Equations	553	(10)
E.1. Four-Level Lasers	553	(6)
E.2. Quasi-Three-Level Lasers	559	(4)
F. Mode-Locking Theory: Homogeneous Line	563	(8)
F.1. Active Mode Locking	563	(5)
F.2. Passive Mode Locking	568	(1)
References	569	(2)
G. Propagation of a Laser Pulse through a Dispersive Medium or a Gain Medium	571	(6)
Reference	575	(2)
H. Higher-Order Coherence	577	(4)
I. Physical Constants and Useful Conversion Factors	581	(2)
Answers to Selected Problems	583	(12)
Index	595