Solar-Pumped Lasers: With Examples of Numerical Analysis of Solid-State Lasers

Contents
1 Brief History of Solar-Pumped Lasers
	1.1 Solar-Pumped Solid-State Lasers
		1.1.1 Progress in Multimode Solar-Pumped Lasers
		1.1.2 Progress in TEM00-mode, Doughnut-Shaped Mode, and Low-Order Mode Solar-Pumped Lasers
		1.1.3 Progress in Solar-Pumped Laser Beam Stability
	1.2 Solar-Pumped Gas Lasers
		1.2.1 Blackbody Pumped CO2 Solar Lasers
		1.2.2 Iodine Solar-Pumped Lasers
	1.3 Potential Applications
		1.3.1 Space-Based Solar-Pumped Laser Applications
		1.3.2 Earth-Based Solar-Pumped Laser Applications
	References
2 Numerical Tools for Solid-State Laser Design
	2.1 Design of Solid-State Lasers by Zemax® Software
		2.1.1 Main Window
		2.1.2 Pumping Sources for Solar Pumped Lasers
		2.1.3 Objects for Solar-Pumped Laser
		2.1.4 Detectors for Ray-Tracing Analysis
		2.1.5 Raytracing
	2.2 Evaluation of Solid-State Laser Output Performance by LASCAD™ Software
		2.2.1 Starting the Program
		2.2.2 LASCAD™ Windows
		2.2.3 Crystal, Pump Beam, and Material Parameter Window
		2.2.4 Analysis of Thermal Lensing Effects by FEA
		2.2.5 Laser Beam Analysis by Beam Propagation Method (BPM)
		2.2.6 Computation of Laser Output Power and Beam Quality
	2.3 Examples of Numerical Solar Pumped Lasers Design: Side-Pumped Solar Laser
		2.3.1 Zemax®
		2.3.2 LASCAD™
	References
3 Solar-Pumped Solid-State Laser Theory
	3.1 Brief Introduction
	3.2 Properties of Laser Radiation
		3.2.1 Directionality
		3.2.2 Monochromaticity
		3.2.3 Coherence
		3.2.4 High Brightness
	3.3 Photons
		3.3.1 Concept and Properties of Photon
		3.3.2 Photon Energy
		3.3.3 Photon Momentum
	3.4 Blackbody Radiation—Planck’ Law
	3.5 Solar Spectral Irradiance from Planck’s Formula
	3.6 Stefan-Boltzmann’s Law
	3.7 Wien’s Displacement Law
	3.8 Spontaneous Emission, Stimulated Absorption and Simulated Emission Probabilities
		3.8.1 Spontaneous Emission Probability
		3.8.2 Stimulated Absorption Probability
		3.8.3 Stimulated Emission Probability
	3.9 Einstein’s Relations
	3.10 Photon Degeneracy in Light from Laser
	3.11 Laser Gain and Stimulated Emssion Cross Section
	3.12 Upper Level Laser Rate Equation
	3.13 Light Intensity Increment Along Active Medium
	3.14 Laser Oscillation Threshold Condition
	3.15 Laser Rate Equation Involving Resonant Cavity
	3.16 Calculation of Photon Density Within a Laser Resonant Cavity
	3.17 Solar Concentration Ratio
	3.18 Transfer Efficiency
	3.19 Absorption Efficiency
	3.20 Deviation Angle and Effective Absorption Length
	3.21 Upper State Efficiency
	3.22 Beam Overlap Efficiency
	3.23 Atom Number Density and Solar Pump Rate Calculations
	3.24 Solar Laser Output Power Calculation
	3.25 Solar Spectral Irradiance and Simplified Model for Nd:YAG Absorption Spectrum
	3.26 Absorbed Solar Power Density and Absorbed Pump Photon Number Density Calculations
	3.27 Output Power Analysis of a Side-Pumped Nd:YAG Solar Laser
		3.27.1 Modified Analytical Method for the Side-Pumped Nd:YAG Solar Laser
		3.27.2 Classical Analytical Method of Side-Pumped Solar Laser
		3.27.3 LASCAD™ Analysis of the Side-Pumped Solar Laser
		3.27.4 Comparison of Different Analysis Methods of the Side-Pumped Solar Laser
	3.28 Output Power Analysis of an End-Side-Pumped Nd:YAG Solar Laser
		3.28.1 Modified Analytical Method for the End-Side-Pumped Nd:YAG Solar Laser
		3.28.2 Classical Analytical Method of the End-Side-Pumped Laser
		3.28.3 LASCAD™ Numerical Analysis of the End-Side-Pumped Solar Laser
		3.28.4 Comparison of Different Analyses for the End-Side-Pumped Solar Laser
	Homework with Solution 1
		Calculation of Resonant Modes Numbers within a Cavity
	Homework with Solution 2
		Deriving Solar Spectral Irradiance from Planck’s Law
	Homework with Solution 3
		Deriving Stefan-Boltzmann’s Law from Planck’s Law
	Homework with Solution 4
		Deriving Wien’s Displacement Law from Planck’s Law
	References
4 Laser Materials for Solar-Pumped Lasers
	4.1 Host Materials
	4.2 Active Ions
	4.3 Nd:YAG
		4.3.1 Physical and Laser Properties of Nd:YAG
		4.3.2 Spectral Overlap Between Nd:YAG Absorption and Solar Emission Spectra
	4.4 Cr:Nd:YAG
		4.4.1 Physical and Laser Properties of Cr:Nd:YAG
		4.4.2 Spectral Overlap Between Cr:Nd:YAG Absorption and Solar Emission Spectra
	4.5 Ce:Nd:YAG
		4.5.1 Physical and Laser Properties of Ce:Nd:YAG
		4.5.2 Spectral Overlap Between Ce:Nd:YAG Absorption and Solar Emission Spectra
	4.6 Other Materials
	References
5 Primary Solar Concentrators
	5.1 Parabolic Concentrator
		5.1.1 Solar Concentration Principles
		5.1.2 Example of Numerical Analysis with Zemax®
	5.2 Fresnel Lenses
		5.2.1 Solar Concentration Principles
		5.2.2 Example Numerical Analysis with Zemax®
	5.3 Elliptical-Shaped Fresnel Lens (ESFL)
		5.3.1 Solar Concentration Principles
		5.3.2 Example Numerical Analysis with Zemax®
	5.4 Single-Ring Array Concentrator
		5.4.1 Solar Concentration Principles
		5.4.2 Example Numerical Analysis with Zemax®
	5.5 3D Ring Array Concentrator
		5.5.1 Solar Concentrator Principle
		5.5.2 Example Numerical Analysis with Zemax®
	5.6 Focal Spot Analysis of Primary Solar Concentrators with ANSYS™ Software
	References
6 Multimode Solar-Pumped Lasers
	6.1 Solar-Pumped Lasers with Imaging and Nonimaging Primary, Secondary and Tertiary Concentrators
		6.1.1 Configurations for Solar Energy Collection and Concentration
		6.1.2 Parabolic Mirrors and Fresnel Lens as Primary Imaging Concentrators
		6.1.3 Secondary Imaging Concentrators
		6.1.4 Secondary Nonimaging Concentrators
		6.1.5 Tertiary Imaging and Nonimaging Concentrators
	6.2 Examples of Numerical Analysis of Milestone Solar-Pumped Lasers
		6.2.1 Zemax® and LASCAD™ Numerical Analysis of 12.3 W Solar Laser with DTIRC Secondary and Conical Tertiary Concentrators
		6.2.2 Zemax® and LASCAD™ Numerical Analysis of 28 W Solar Laser with a Fused Silica Light Guide Homogenizer and a 2D-CPC Pump Cavity
		6.2.3 Zemax® and LASCAD™ Numerical Analysis of Simultaneous Solar Laser Emissions from Three Ce:Nd:YAG Laser Rods Within a Single Pump Cavity
	References
7 High Brightness Solar-Pumped Lasers
	7.1 Solar Laser Pumping Configurations for TEM00-mode
		7.1.1 Side-Pumping Configuration
		7.1.2 End-Side-Pumping Configuration
	7.2 Solar Laser Pumping Configurations for Doughnut-Shaped and Low-Order Modes Emissions
		7.2.1 Side-Pumping Configuration
		7.2.2 End-Side-Pumping Configuration
	7.3 Techniques of TEM00-Mode Solar Laser Power Extraction
		7.3.1 Thermal Lensing Effect and Thermal Focal Length
		7.3.2 Influence of Laser Resonant Cavity Parameters
		7.3.3 Influence of Solar Pumping Conditions
		7.3.4 Influence of Laser Rod Dimensions
	References
8 Solar Tracking Error in Solar-Pumped Lasers
	8.1 Brief Introduction
	8.2 Sun Trajectory and Error Formation in Solar Energy Collection and Concentration Systems
		8.2.1 Sun Trajectory in the Sky During the Day
		8.2.2 Error Formation in Solar Energy Collection and Concentration Systems
	8.3 Solar Tracking Systems
		8.3.1 Direct Solar Tracking Mode
		8.3.2 Indirect Solar Tracking Mode by Heliostats
	8.4 Tracking Error in Different Primary Solar Concentrators
		8.4.1 Solar Tracking Error in Parabolic Mirrors
		8.4.2 Solar Tracking Error in Fresnel Lenses
		8.4.3 Solar Tracking Error in Ring-Array Concentrators
	8.5 Tracking Error Compensation Techniques
		8.5.1 Monolithic Fused Silica Twisted Light Guide
		8.5.2 Multi-Rod Pumping Approach
	8.6 Example of Numerical Modeling of Solar-Pumped Lasers with Tracking Error Compensation Capacity
		8.6.1 Zemax® and LASCAD™ Analysis of the Tracking Error Compensation Capacity Using Multi-Rod Configurations
	References