A prism is a solid glass object with a specific geometric shape designed to disperse, deviate, rotate, or displace a beam of light. A micro prism, as the name suggests, is a very small version of an optical prism. Though there are many types of prisms, micro prisms are generally used to direct light in fiber optic communications, particularly in optical switches. Two types of micro prisms prove useful for these and other applications.
What Makes Micro Prisms Important?
Micro prisms provide an efficient way to change a beam of light’s directory inside an assembly or fiber optic device. When light passes through one of the faces of the prism, it is refracted. Depending on the design of the prism, the light may be directed at various angles before exiting. The main purpose of a micro prism in fiber optics is to direct beams of light from one optical channel to another with high precision. Although micro prisms are small, they offer several significant advantages to the optics projects that use them, including:
- Precise deviation: The faces and angles of a prism are carefully engineered to meet precise calculations. When light enters the prism, it deviates at the intended angle with a high level of consistency. The light reaches its destination more reliably than in systems using mirrors or multiple components, which require perfect alignment to function.
- High reflectivity: Micro prisms have high reflectivity, helping to minimize signal loss. At Shanghai Optics, for example, we manufacture micro prisms with reflectivity greater than 95 percent per face for 1550 nm wavelengths.
- Small size: The small size of micro prisms allows light to be directed with high accuracy while maintaining a relatively small device size. A micro prism takes up minimal space inside an assembly or optic switch, contributing to the compactness and efficiency of the technology.
All these benefits make a micro prism ideal for use as a circulator, interleaver or MEMS in fiber optic applications.
Micro Penta Prisms
| General Specifications | |
| Material: BK7 Grade A optical glass, Corning Fused Silica 7980, JGS1, JGS2 | |
| 90° Deviation Tolerance: | Standard series: < 5 arc seconds Precision series: < 2 arc seconds |
| Flatness: | Standard series: λ/4 at 632.8 nm Precision series: λ/8 at 632.8 nm |
| Reflectivity: R > 95% per face from @1550 nm | |
| Surface Quality: 40-20 scratch and dig | |
| Working Wavelength: 1310, 1550, 1590 nm | |
Micro Right-Angle Prisms
| General Specifications |
| Dimension Tolerance: +0.0, -0.1 mm |
| Clear Aperture: > 90% |
| Flatness: l/2 l@632.8 nm |
| Surface Quality: 40-20 scratch and dig |
| Reflectivity: R>95% per face @ center wavelength |
| Working Wavelength: 1310, 1550, 1590 mm |
| Bevel: 0.1 mm to 0.2 mm |
How Micro Prisms Are Produced
A micro prism’s performance is closely tied to its design and manufacturing. In general, micro prisms are cut and ground from optical glass, polished to meet precise specifications, coated (if needed), and checked for defects. At Shanghai Optics, we produce both coated and uncoated micro prisms, depending on the customer’s needs.
- Penta micro prisms: The penta micro prism has the shape of a pentagon, featuring seven faces and providing a stable light deviation of 90 degrees, regardless of where the light enters the prism. We manufacture our micro penta prisms using a variety of substrate materials, including BK7 Grade-A optical glass, Corning Fused Silica 7980, JGS1, and JGS2.
- Right-angle micro prisms: Right-angle micro prisms have the shape of a right triangle, with two parallel triangular faces and three rectangular faces. These prisms can deviate light by 90 degrees or 180 degrees, depending on which face the light initially enters. Our right-angle micro prisms have a bevel between 0.1 and 0.2 mm.
Though these prisms feature different shapes, they share many of the same physical properties, including reflectivity, surface quality, and working wavelength. Shanghai Optics can produce custom micro prisms using a variety of materials and coatings, including coatings for different UV, visible, and IR wavelengths upon request.
Order Custom Micro Prisms From S.O.
Right-angle and penta micro prisms have numerous applications in fiber optics and beyond. Many of these applications require prisms that are tailored to unique specifications and fine-tuned for optimal performance. At Shanghai Optics, we manufacture micro prisms that meet both of these requirements. To ensure that our custom optical switch prisms meet your specifications, our production staff adheres to ISO 9001 standards and uses state-of-the-art metrology equipment to test performance. See how we can assist with your current optics project by requesting a quote or contacting one of our friendly representatives for more information.
Need help?
We offer consultations and initial feasibility studies. If you have questions about limitations or lens capabilities we’re more than happy to work through your proposed custom components. As an unmatched custom optical provider, we’ll do everything that we can bring your vision to life.
