Wedge prism
Wedge prism
Wedge prisms are precision optical components featuring a shallow angle between their input and output surfaces, typically 3 degrees or less. This slight angular difference causes the prism to deflect light by a fixed angle, making it an essential tool in various optical applications. When viewed through a wedge prism, objects appear offset, with the degree of offset varying based on their distance from the prism.
Key Specifications and Optical Principles
The deflection angle (δ) for a wedge prism in air can be approximated by the equation:
δ≈(n−1)α
where n represents the refractive index of the prism material and α is the angle between the prism’s surfaces. This relationship highlights how the prism’s material and geometry contribute to its light-deflecting capabilities.
Applications of Wedge Prisms
Wedge prisms, also known as optical wedges, are employed in a variety of applications. These prisms, with wedge angles ranging from a few millionths of a degree to as much as three degrees, are crucial in fields such as laser beam steering, rangefinding, and variable focusing.
Laser Beam Steering:
A pair of wedge prisms, known as a Risley prism pair, is often used for precise beam steering. By rotating one wedge relative to the other, the direction of the beam can be finely adjusted. When the prisms are angled in the same direction, the refracted beam angle increases; when angled oppositely, the effects cancel out, allowing the beam to pass straight through.
Moving the wedge prisms closer to or farther from the laser source can also steer the beam across a target. This setup is especially useful in dynamic applications where the distance to the target changes rapidly, such as in aerial or space photography.
Variable Focusing:
When two wedge prisms slide relative to each other in opposite directions, they can provide variable focusing capabilities. This method is particularly useful in capturing images of objects at varying distances, keeping them in focus at the same focal plane. This technique is commonly employed in specialized photography applications, including those involving fast-moving objects or changing distances.
Rangefinding:
Wedge prisms have also been used in rangefinding devices, where they combine images from two telescopes to measure distances accurately.
MOK Optics’ Wedge Prisms
MOK Optics provides high-precision wedge prisms crafted from materials such as BK7, UV fused silica, and CaF2. These prisms are designed to meet the exacting standards required for applications like laser beam steering and variable focusing. Coating options are available to suit various needs, including no coating, anti-reflective (AR) coating, and dichroic mirror coating, ensuring optimal performance across a wide range of optical setups.
Our wedge prisms are engineered for precision and reliability, making them ideal for use in advanced optical systems where accuracy and performance are paramount. Whether you’re working with lasers, telescopes, or specialized imaging systems, MOK Optics’ wedge prisms offer the quality and versatility needed to achieve your goals.