Fundamental Optics – Part 1: Curved Mirrors

Understanding the fundamentals of working with optical sensors will help you with future robotics engineering projects. There are two primary types of optics: reflective and refractive. George introduces reflective optics in this article. Topics Covered How to understand the fundamentals of opticsHow do concave mirrors work?How do convex mirrors work?What's the difference between reflective and refractive optics? Tech Discussed Optical sensorsConcave mirrorsConvex mirrors Designers of embedded and robotic systems are increasingly faced with the use of optical sensors. In most instances, these need additional optics for their operation. The design of optical systems is an engineering discipline in its own right, requiring years of study and experience. Present-day optical systems are designed with the help of computers, but many of those systems can be analyzed and understood by simple manual ray tracing. This can be accomplished the old-fashioned way with a piece of paper, a straight edge, and a pencil. As electrical engineers we do not have to be able to design optics, even though some optical rules apply in electrical engineering. Dish and Yagi antennas are two examples. This three-part series will not make you an optical expert, but it will explain the fundamentals, which will be helpful when you're working with optical sensors. PRIMARY OPTICSThere are two primary types of optics: reflective and refractive. It is not unusual to find both types combined in a single system, such as in a telescope. With some exceptions, most optical systems consist of numerous elements to achieve the desired characteristics. Understanding the characteristics of the individual elements is the first step to understanding the characteristics of the entire system. Reflective elements are mirrors, usually called curved mirrors. They work by reflecting light rays in a predetermined way. Their curvature is often spherical, meaning the mirror is a portion of a spher