Beam Splitters
Polarizing Beam Splitters are an optical device used in various applications to divide a beam of light into two separate beams with distinct polarization states. They are an important component in many optical systems, including microscopy, interferometry, laser systems, and telecommunications.
The basic function of a polarizing beam splitter is to transmit light of a certain polarization while reflecting light of orthogonal polarization. It splits an incoming unpolarized or randomly polarized light beam into two separate output beams: one that retains its original polarization and another that has its polarization perpendicular to the input polarization.
Polarizing beam splitters are constructed using birefringent materials or thin films that exploit the polarization-dependent reflection and transmission properties. The most common type of polarizing beam splitter is made using a combination of a dichroic prism or cube and a thin film polarizer.
The unpolarized or randomly polarized light enters the Polarizing Beam Splitter. The incoming light beam then encounters a dichroic plate, prism or cube, which is made of a birefringent material like calcite or other appropriate crystals. The crystal structure of these materials causes them to exhibit different refractive indices for light polarized parallel and perpendicular to a specific axis. In combination with the dichroic prism/cube, a thin film polarizer is often used to enhance the polarization separation. The thin film polarizer is designed to reflect one polarization state while transmitting the other.
As the light passes through the dichroic prism or cube, its polarization is split into two orthogonal components. One polarization component is transmitted through the prism/cube and the thin film polarizer, while the other polarization component is reflected by the thin film polarizer. The two polarized components of light exit the PBS as separate beams with distinct polarization states. One beam retains the original polarization, and the other beam has its polarization state rotated by 90 degrees.
Polarizing beam splitters are essential tools in optical systems where the separation or manipulation of polarized light is required. They find applications in polarimetry, imaging systems, laser setups, and other fields where precise control over polarization is necessary.
Firebird Optics offers them in both plate and cube configurations for both polarizing and non-polarizing applications. Beam splitters are constructed from high quality glass, calcite and other birefringent materials with tight tolerances on both surface flatness and quality, enabling them to be used in laser applications.
Wollaston Prisms
Wollaston Prisms
Firebird Optics’ Wollaston prisms are beamsplitters that split unpolarized light into two orthagonally polarized outputs. Comprised of prisms cemented together. Available in Calcite, Quartz and Magnesium Fluoride (MgF2). α-BBO is available upon request.
Features:
Made from high-grade polarizing materials
Separates broadband light into two polarized beams
Provides a 20º separation angle
Extinction ratio ＜5×10-6 for all materials except for quartz, which is ＜5×10-5
Wavelength range: dependent on material
Low wavefront distortion
Specs:
Calcite Prisms:
15mm OD, 5mm CA, 14mm L
25.4mm OD, 8mm CA, 16mm L
Coating: 350-2300nm (Coating @990nm)
Extinction ratio: ＜5×10-6
Angular field: 19°@990nm
Quartz Prisms:
15mm OD, 6mm CA, 20mm L
25.4mm OD, 8mm CA, 24mm L
Coating: 200-2300nm (Coating @1064nm)
Extinction ratio: ＜5×10-5
Angular field: 2°@1064nm
MgF2 Prisms:
15mm OD, 6mm CA, 19.5mm L
25.4mm OD, 8mm CA, 23.5mm L
Coating: 130-4000nm
Extinction ratio: ＜5×10-6
Angular field: 2.7°@1064nm
Wollaston Prisms: An Introduction to Polarization Optics
Polarization optics is a branch of optics that deals with the manipulation and analysis of the polarization state of light. It is a fundamental aspect of modern optical technology and plays a crucial role in a wide range of applications, from astronomy and microscopy to telecommunications and medicine. One of the most important tools in the field of polarization optics is the Wollaston prism, which is widely used for splitting and analyzing polarized light. In this article, we will provide an overview of Wollaston prisms and their applications in polarization optics.
What is a Wollaston Prisms?
A Wollaston prism is a type of birefringent prism that splits an incident beam of polarized light into two orthogonally polarized components. It was invented by William Hyde Wollaston in 1802 and is commonly used in optical microscopy, spectroscopy, and polarimetry. The prism is made of two calcite crystals that are cemented together with their optic axes perpendicular to each other. The two crystals have slightly different refractive indices, which causes the prism to split an incident beam of polarized light into two beams that are deflected at different angles.
Working Principle of Wollaston Prisms
The working principle of a Wollaston prism is based on the birefringence of calcite crystals. When a beam of light enters the prism, it is split into two beams that travel through the prism at different speeds due to the difference in refractive indices of the two calcite crystals. As a result, the two beams are deflected at slightly different angles, depending on their polarization state. The angle of separation between the two beams depends on the thickness of the prism and the wavelength of the incident light.
Applications of Wollaston Prisms
Wollaston prisms have a wide range of applications in polarization optics. One of the most important applications is in polarimetry, where they are used to analyze the polarization state of light. By measuring the angle of separation between the two beams produced by a Wollaston prism, the degree of polarization of the incident light can be determined. Wollaston prisms are also used in optical microscopy, where they are used to observe birefringent materials such as crystals, fibers, and biological tissues. They are also used in spectroscopy, where they are used to analyze the polarization state of light emitted by atoms and molecules.
Advantages and Disadvantages of Wollaston Prisms
One of the main advantages of Wollaston prisms is their simplicity and ease of use. They can be easily integrated into optical systems and require minimal alignment. They also have a high degree of accuracy and are capable of splitting light into two orthogonally polarized components with a high degree of separation. However, Wollaston prisms also have some disadvantages. They are sensitive to temperature changes and can cause chromatic aberrations due to the different refractive indices of the two calcite crystals. They are also relatively expensive compared to other types of polarizing prisms.
Conclusion
Wollaston prisms are an important tool in polarization optics, providing a simple and effective way to split and analyze polarized light. They are widely used in a range of applications, from microscopy and spectroscopy to polarimetry and telecommunications. While they have some disadvantages, their advantages outweigh their drawbacks, making them an essential component of many optical systems.
