Use of smartphones in optical experimentation Use of Smartphones in Optical Experimentation shows how smartphone based optical labs can be designed and realized. The book presents demonstrations of fundamental geometric and physical optical principles including the law of reflection the law of refraction image formation equations dispersion Beer’s law polarization Fresnel’s equations optical rotation diffraction interference and blackbody radiation. Many practical applications—how to design a monochromator and a spectrometer use the Gaussian beam of a laser measure the colors of LED lights and estimate the temperature of an incandescent lamp or the Sun—are also included. The experimental designs provided in this book represent only a hint of the power of leveraging the technological capability of smartphones and other low cost materials to create a physics lab. This book can be used as a guide for undergraduate students and instructors for a hands on experience with optics especially for an online optical lab; elementary and high school science teachers to develop smartphone based labs for classroom demonstrations; and anyone who wants to explore fundamental STEM concepts by designing and performing experiments anywhere.