Laser Beam Caustic: Explained
One parameter that can be used to evaluate the quality of a laser beam is what’s called a Beam Caustic. A caustic, in general, is an “envelope” that defines the extent of a beam of light after they have been refracted (or reflected ) by a curved surface. As the light beams propagate they cross […]
Unlocking Risley Prisms Precision in Optical Steering OFH
Introduction Previous posts have explained reflective, anamorphic and dispersive prisms and their use in optical systems. Today we will explain a prism configuration called Risley Prism. A Risley prism is actually two wedge prisms close to each other that can be rotated independently. This configuration was first used in optometry to measure the misalignment of […]
Mastering Relay Lens Design: Enhancing Optical Systems | OFH
Introduction Optical relays, an integral component of various optical systems, play a crucial role when the user’s proximity to the observed object is limited or when specific image transformations are required. A prevalent example of this is found in relay lenses, often employed in scenarios where physical closeness to the object is impractical, as seen […]
Phase Shift Method for distance measurement
Optical techniques for distance measurement offer plenty of uses and applications. These techniques are able to measure the distance between two objects without touching them, making them perfect for a variety of situations. Optical techniques are usually the best solution when needing a noncontact method that’s fast or automated. For example, they are often used […]
Screen Scratch Detection System
The resale value of a used smartphone is highly dependent on the quality of the screen. In this project, we demonstrate methods to automatically identify screen scratches and determine screen quality using a custom imaging and illumination layout and computer vision software. Key elements of the design include: The device is a box inside which […]
Cardinal Points
When I was a young undergrad engineering student, I always found optics to be a very confusing subject. It was not only the equations, but what it looked like hundreds of different definitions involved in even the simplest of optical systems. Some concepts, like radius of curvature, f-number, and focal point were easy to understand […]