What is a Rhombus Prism?
A rhombus prism is an optical prism with parallel rhomboid faces. It is specially designed to deflect light without inverting or shifting the image. This unique characteristic makes rhombus prisms invaluable in optical systems that require beam deflection and displacement without altering the image orientation.
Key Characteristics of a Rhombus Prism
Beam Displacement: The primary function of a rhombus prism is to laterally displace the incident beam without changing its direction. This lateral displacement is equal to the length of the prism.
Image Inversion Prevention: Unlike some other prisms, rhombus prisms do not invert the image, making them suitable for imaging applications.
Material Composition: Rhombus prisms are typically made of optical glass (e.g., BK7), ultraviolet-grade fused silica, or infrared crystals (e.g., sapphire, MgF2, and CaF2), materials that ensure their excellent optical performance.
How a Rhombus Prism Works？
The working principle of a rhombus prism is total internal reflection. Light entering a prism is reflected by two 45-degree angled facets before leaving the prism. This internal reflection allows the prism to laterally shift the beam while maintaining its original direction and orientation.
Total Internal Reflection
Rhombic prisms are typically uncoated, relying on total internal reflection to achieve their optical effects. However, for applications requiring a wider angular range, coatings can be applied to enhance their performance.
Coating Options
Antireflective Coating: Antireflective coatings can be applied to improve transmittance.
High-Reflectivity Coating: High-reflectivity coatings are used for specific applications.
Beam Splitting Coating: This coating enables the prism to split the light beam into two parallel beams at different positions.
Applications of Rhombic Prisms
Rhombic prisms are widely used components in various fields due to their unique properties. Here are some of their main applications:
Imaging Systems
In imaging applications, rhombic prisms can change the optical axis position without inverting the image, making them ideal for systems that require maintaining image orientation.
Laser Systems
Rhombic prisms are commonly used in laser systems for precise beam direction control. They can move the beam laterally without changing its direction, which is crucial for compact optical paths with limited space.
Metrology
In metrology, the precise angular specifications of rhombic prisms ensure accurate light deflection, making them suitable for high-precision measurement systems.
Stereoscopic and Periscope Systems
Because rhombic prisms can change the position of the beam without altering its direction, they are commonly used in stereoscopic and periscope systems.
Rhombic Prism Manufacturing: MOK Optics Process
MOK Optics is a leading manufacturer of high-quality rhombic prisms. Their manufacturing processes include:
Material Selection
- Optical Glass: CDGM, SCHOTT, OHARA, HOYA
- UV-grade Fused Quartz: JGS1, Corning 7980
- IR-grade Fused Quartz: JGS3, Corning 7979
- IR Crystal: Sapphire, MgF2, CaF2
- Precision Specifications
- Size Range: 2mm-200mm
- Dimensional Tolerance: ±0.02mm
- Light Transmittance: >90%
- Surface Quality: Up to 10⁻⁵
- Flatness: Up to λ/10@632.8nm
- Tolerance: Up to 30 seconds
Custom Coating Design
- MOK Optics offers custom coating designs to meet specific application needs, ensuring that each prism is tailored to the customer’s requirements.
Conclusion
Rhomboid prisms are powerful evidence of advancements in optical technology. Their ability to move laser beams without changing direction or image orientation makes them indispensable in a wide range of applications, from imaging to laser systems. As technology continues to advance, the demand for precision optical components such as rhombic prisms will only continue to grow. For users interested in exploring the application possibilities of rhombic prisms, MOK Optics offers a range of customizable options to meet specific application needs.