Preface

This book covers various aspects of using the laser ablation phenomenon for material proc‐ essing including laser ablation applied for the deposition of thin films, for the synthesis of nanomaterials, for the chemical compositional analysis, and for the surface modification of materials. Through the 18 chapters written by experts from the international scientific com‐ munity, the reader will have access to the most recent research and development findings on laser ablation through original research studies and literature reviews. Chapter 1 presents an overview on laser ablation for the synthesis of thin films including the descrip‐ tion of three main types of laser thin film deposition techniques: pulsed laser deposition (PLD), combinatorial pulsed laser deposition (CPLD), and matrix assisted pulsed laser evap‐ oration (MAPLE). The chapter uses a number of examples to illustrate the effect of process‐ ing parameters on the quality and property of thin films, as well as the advantages and disadvantages of thin film deposition by laser. Chapter 2 successfully exploits the use of PLD to grow excellent quality and high performance thin phosphor films of Ca0.5R1 x(MoO4)2:xLn3+, M+ (R3+ = La, Y), (Ln3+ = Eu, Tb, Dy) (M+ = Li+ , K+ and Na+ ) for electrolumines‐ cence and display applications. Chapter 3 describes the use of PLD to grow and control the thermoelectric properties and novel topological surface states of bismuth chalcogenide (e.g., Bi2Te3, Bi2Se3, and Bi3Se2Te) thin films by varying ambient pressures and substrate tempera‐ tures. Chapter 4 presents an overview on the deposition of indium-tin oxide (ITO) films by PLD. The effect of laser wavelength, substrate temperature, and background gas on the re‐ sistivity and transmittance of ITO films, as well as ITO nanostructures, is systematically in‐ vestigated. Chapter 5 presents the results of the characterization and in vitro evaluation of calcium phosphate films deposited by PLD or MAPLE. The results presented in Chapter 5 confirm that excellent quality and high-performance biomaterial thin films can be deposited by PLD and MAPLE for medical applications. Chapter 6 presents an exciting new method for making nanocomposite films based on multi-beam laser ablation/evaporation processes with the acronym MBMT-MAPLE/PLD. The feasibility of the new deposition technique is demonstrated for making polymer nanocomposite films with two inorganic additives: up‐ conversion fluorescent phosphor NaYF4:Yb3+, Er3+, and aluminum-doped ZnO. Chapter 7 describes methods to obtain uniform deposition of thin film over large areas on rotating substrates and moving ribbons by PLD technique. These methods, such as tilting targets and using shadow masks of different shapes, are simple, low cost, and can be easily adapted by existing PLD systems. Implementation of these methods not only can improve thickness uniformity and reduce micro/sub–micro-sized particles for PLD films but also can increase the utilization of targets. Chapter 8 gives an overview on using laser ablation to fabricate nanoparticles in different environments such as vacuum, ambient air, different liquid envi‐ ronments, and different background gases. The chapter analyzes in detail laser ablation mechanisms in each environment and suggests that each medium possesses some unique advantages and disadvantages for nanomaterial production or machining. Chapter 9

presents interesting works on using laser ablation in a liquid environment to synthesize sev‐ eral important compounds, such as hydrocerussite Pb3(CO3)2(OH)2; CdS quantum dots; magnetic materials such as Fe, FeO, NaFeO3, Na2FeO4; and metal organic frameworks Cu2 (BTC)2(H2O)3, Eu(TMA)(H2O)4. The chapter provides convincing mechanisms for each syn‐ thetic process and demonstrates that laser ablation in a liquid environment is a simple, lowcost, chemically clean, and one-pot synthetic route that enables fabrication of numerical practically important materials. Chapter 10 gives an overview on the use of pulsed laser ablation for the synthesis of nanomaterials under high-pressure gases, liquids, and super‐ critical fluids media. Chapter 11 provides detailed descriptions of the physical and chemical processes occurring during laser ablation in liquids for the synthesis of nanoparticles. The parameters that affect the formation, composition, and structure of the nanoparticles ob‐ tained are also discussed. Chapter 12 presents two very interesting applications of laser ablation in liquid phase: (i) organic nanoparticle formation by laser ablation of organic mate‐ rials and (ii) hydrogen gas generation and nanoparticle generation by ablation of solid car‐ bon in water. The chapter also reveals the mechanism of hydrogen generation by laser ablation. Chapter 13 presents the design of a pulsed laser vaporization reactor that can be used to synthesize single-wall carbon nanotubes, carbon nano-onions, and graphene by just tuning the experimental parameters. Chapter 14 presents the use of femtosecond for laser micromachining of fiber optics with a focus on investigation of the effects of laser parame‐ ters on surface qualities. The chapter describes different aspects of laser induced periodic surface structures and gives an example of using femtosecond laser for the fabrication of fiber optic sensors. Chapter 15 presents the use of dual-color laser that consists of the funda‐ mental (ω) and its second harmonic (2ω) of a femtosecond Ti:sapphire for the ablation of PMMA. By changing the relative phase of the fundamental (ω) and second-harmonic (2ω) outputs, the chapter demonstrates that the laser ablated area can be modulated. Chapter 16 reports on the use of three lasers to modify the surface of the allyl-diglycol CR39 polymer in order to fabricate optical waveguides. Chapter 17 presents a new application of laser abla‐ tion for characterization of material ablation resistance by giving examples in ablation-resist‐ ance characterization of ultrahigh temperature ceramics and ceramic matrix composites and provides convincing interpretation of laser ablation behavior and mechanisms. Chapter 18 discusses the use of laser ablation for chemical compositional analysis of materials and ex‐ ploits different methods for normalization of the laser ablation inductively coupled mass spectrometry in order to reduce measurement-related fluctuations.

This publication provides a snapshot of current efforts to extend the use of laser ablation for processing of materials and will be useful for the researchers and students who work in the area of laser and manufacturing. I gratefully acknowledge all chapter authors for their en‐ thusiastic and collaborative contributions, and thanks to Ms. Maja Bozicevic, Publishing Process Manager, for her guidance and support in the preparation of this book.

**Dongfang Yang, PhD**

Senior Research Officer Automotive and Surface Transportation National Research Council Canada London, Ontario, Canada

**Section 1**
