Book excerpt: Lasers and Optical Instrumentation covers B.E., M.E., and M. Sc. (Electronics) degree courses. The text covers basic principles of lasers, types of lasers and their characteristics, laser applications in engineering and medicine. Further the book includes extensive coverage of optoelectronic devices, fibre optic communication and fibre optic sensors. The book includes many solved problems throughout the text to support the theoretical concepts and help in understanding of underlying principles. Review questions have been included at the end of each chapter to practise and self-study. Spread in Ten Chapters the book broadly covers: " Characteristics of lasers, mode locking, Q-switching, powerful lasers, frequency stabilisation " Overview of applications of lasers in science, engineering and medicine; reliability and safety aspects " Laser interferometer, laser strain gauges, laser Doppler velocimeter, laser ranging, mechanical cutting, welding, scribing, holography " Applications of Raman spectroscopy " Application of laser devices, optical fibers etc., in fiber optic communications " Integrated optics, radiation source, transmission link, detector " Fibre optical sensors, non-intrusively, displacements, pressure, temperature, high currents, angular velocity " Future perspectives nanophotonics, quantum dots, photonic crystals