Until recently, ceramic materials were considered unsuitable for optics due to the numerous scattering sources, such as grain boundaries and residual pores. However, in the 1990s the technology to generate a coherent beam from ceramic materials was developed, and a highly efficient laser oscillation was realized. In the future, the technology derived from the development of the ceramic laser could be used to develop new functional passive and active optics. Co-authored by one of the pioneers of this field, the book describes the fabrication technology and theoretical characterization of ceramic material properties. It describes novel types of solid lasers and other optics using ceramic materials to demonstrate the application of ceramic gain media in the generation of coherent beams and light amplification. This is an invaluable guide for physicists, materials scientists and engineers working on laser ceramics.

Invaluable guide for physicists, materials scientists and engineers working on laser ceramics, co-authored by a pioneer of the subject.

Transparent ceramic materials have several major advantages over single crystals in laser applications, not the least of which is the ability to make large aperture parts in a robust manufacturing process. After more than a decade of working on making transparent YAG:Nd, Japanese workers have recently succeeded in demonstrating samples that performed as laser gain media as well as their single crystal counterparts. Since then several laser materials have been made and evaluated. For these reasons, developing ceramic laser materials is the most exciting and futuristic materials topic in today's major solid-state laser conferences. We have established a good working relationship with Konoshima Ltd., the Japanese producer of the best ceramic laser materials, and have procured and evaluated slabs designed by us for use in our high-powered SSHCL. Our measurements indicate that these materials will work in the SSHCL, and we have nearly completed retrofitting the SSHCL with four of the largest transparent ceramic YAG:Nd slabs in existence. We have also begun our own effort to make this material and have produced samples with various degrees of transparency/translucency. We are in the process of carrying out an extensive design-of-experiments to establish the significant process variables for making transparent YAG. Finally because transparent ceramics afford much greater flexibility in the design of lasers, we have been exploring the potential for much larger apertures, new materials, for example for the Mercury laser, other designs for SSHL, such as, edge pumping designs, slabs with built in ASE suppression, etc. This work has just beginning.

The goal of this program was to ascertain the possibility of developing a Tunable Solid State Laser, based on Cr - doped transparent glass - ceramics. To this end the spectroscopy of Cr in mullite ceramics and related aluminosilicate crystals was studied in detail. The results indicate an extremely large inhomogenous broadening, interpreted in terms of a statistical distribution of crystal fields. The main limitation of these materials is the high scattering loss which should be reduced by at least a factor of 10, before laser applications are contemplated. Work on scattering led to the discovery of un-averaged, angularly distributed intensity fluctuations in amorphous materials. This work was carried out on CVD silica as well as on ceramics and led to new insights concerning the statistics of speckle phenomena. Keywords: Laser materials; Tunable solid-state lasers; Spectroscopy; Chromium glass doping; Chemical vapor deposition; Transparent ceramics; Light scattering from amorphous solids; Speckle; Backscattering. (EDC).

This book introduces the applications of laser in surface modification, such as laser cladding of Stellite alloys and metal-ceramic composites. Besides, nanomaterials including carbon nanotubes and Al2O3 nanoparticles are brought into the laser processing, to form high-temperature resistance, chemical stability, and wear- and oxidation-resistant composite coatings. The readers will get more knowledge about the basic principle and application of laser cladding and laser surface hardening technologies, and gain a deep insight into the process and characteristics of the nanomaterial-assisted laser surface enhancement. It provides references for the researchers, engineers, and students in the fields of mechanical engineering, laser processing, and material engineering.

Most people would be surprised at how ceramics are used, from creating cellular phones, radio, television, and lasers to its role in medicine for cancer treatments and restoring hearing. The Magic of Ceramics introduces the nontechnical reader to the many exciting applications of ceramics, describing how ceramic material functions, while teaching key scientific concepts like atomic structure, color, and the electromagnetic spectrum. With many illustrations from corporations on the ways in which ceramics make advanced products possible, the Second Edition also addresses the newest areas in ceramics, such as nanotechnology.

Millimeter-wave processing (sintering) of ceramic laser host materials has been under investigation at the Naval Research Laboratory (NRL) for high energy laser (HEL) applications. Advantages of polycrystalline, compared to single-crystal laser host materials, include lower processing temperature, higher gain from higher dopant concentrations, cheaper fabrication, and larger devices. Millimeter-wave processing has been shown to be an effective alternative to conventional vacuum furnaces for pressure-free sintering of low-loss oxide ceramic materials. It involves direct volumetric heating of the workpiece. This often results in superior microstructure with fewer trapped pores, cleaner grain boundaries, and smaller grain size than conventionally sintered materials. These properties are critical to achieving high optical quality laser host materials. The absorbed power per unit volume in a ceramic is proportional to the microwave frequency. Thus the power loss is a function of both the temperature of the ceramic and the frequency; at a given frequency, oxide ceramics tend to be more absorbing at higher temperatures, and at a given temperature, an oxide ceramic is more absorbing at higher frequencies. The NRL gyrotron-based material processing facility features a 15 kW, continuous wave, 83 GHz GYCOM gyrotron oscillator, which can generate between 1 W/sq cm and 2 kW/sq cm irradiance. The facility features a quasi-optical beam system for beam focusing and manipulation and an inner vacuum chamber for atmosphere control and vacuum processing. The gyrotron is operated via a fully automated computerized control system written in the LabVIEW platform with feedback from extensive in-situ instrumentation and visual process monitoring. The system has the capability of sample rotation and translation during processing.