This text is essential for anyone who wishes to test or measure optical sub-components, components, systems, or devices. Dennis lays out the fundamentals of each measurement in an easy to understand format. This is especially useful because this field is growing tremendously and often utilizes people from other fields who lack familiarity with these measurements. This book provides as easy to understand tutorial for people who need to learn these techniques. If you can't measure what you have very well, you don't know what you sent to your customer; and if they can't measure what you sent them, they don't know what they have.