The ability of light to exert forces has been known for quite some time. In fact, Johannes Kepler (1619) recognised that the tails of a comet — an example of which is shown in Fig. 1.1 — are due to the force exerted on the particles surrounding the comet’s body by the Sun’s rays. However, optical forces are extremely small. So small, in fact, that only in recent years, and only thanks to the advent of the laser, it has been possible to concentrate in a small area enough optical power to significantly affect the motion of microscopic particles, thereby leading to the invention of the optical tweezers. Optical tweezers are generated by a tightly focused laser beam that can hold and manipulate a particle in the high-intensity region that is the focal spot. Optical tweezers and other optical manipulation techniques have heralded a revolution in the study of microscopic systems, spearheading new and more powerful techniques, e.g., to study biomolecules, to measure forces that act on a nanometre scale and to explore the limits of quantum mechanics. This Book provides a comprehensive guide to the theory [Chapters 2-7], practice [Chapters 8- 12] and applications [Chapters 13-25] of optical trapping and optical manipulation.
1.1 A brief history of optical manipulation
1.2 Crash course on optical tweezers
1.3 Optical trapping regimes
1.4 Other micromanipulation techniques
1.5 Scope of this Book
1.6 How to read this Book
1.7 OTS – The Optical Tweezers Software