ABSTRACT
The immense value of optical tools in characterizing materials has continually driven the development of innovative optical techniques and systems. These novel techniques can offer several advantages over existing optical characterization methods, such as extending the range of data that can be obtained on a given material, enabling one to obtain this data in a simpler manner, providing greater precision and accuracy in the measured data, or revealing information on a specic material functionality. The leading optics and applied physics journals thus report new optical techniques that address one or more of the issues mentioned earlier on a nearly weekly basis, one indicator of the sheer volume of activity in this area. This clearly makes it impossible to even attempt to describe the full range of experimental optical techniques in a single book. Therefore, in previous chapters, we have focused on mature techniques that are each uniquely capable of determining a given set of material properties, from the use of four-wave mixing to measure ultrashort dephasing times to the ability of near-eld
CONTENTS
18.1 Advanced Time-Resolved Optical Techniques 664 18.1.1 Ultrafast Structural Dynamics 665
18.1.1.1 Ultrafast X-Ray Diffraction and Absorption 667 18.1.1.2 Ultrafast Electron Diffraction, Crystallography, and Microscopy 671
18.1.2 Ultrafast Photoelectron Spectroscopy 675 18.2 Optical Techniques That Combine High Temporal and Spatial Resolution 681
18.2.1 Time-Resolved Optical Microscopy in the Far Field 681 18.2.1.1 Time-Resolved Wide-Field Optical Microscopy 682 18.2.1.2 Time-Resolved Scanning Optical Microscopy in the Far Field 685
18.2.2 Time-Resolved Near-Field Scanning Optical Microscopy 689 18.2.3 Ultrafast Scanning Tunneling Microscopy 692
18.3 Conclusion 695 References 696
scanning optical microscopy (NSOM) to spatially resolve nanoscale features in a noncontact manner. However, several emerging methods can characterize previously inaccessible material properties, such as changes in crystal structure, electronic band structure, and carrier transport, at unprecedented time and length scales. This makes them worthy of inclusion in this book, albeit in an all-too-brief description.
