Dichroic polarizers is a special optical filters designed to polarize electromagnetic radiation through the process of anisotropic absorption. These beamsplitters transmit only light with the desired polarization states, absorbing the rest.
At Shanghai Optics we produce some of the highest quality dichroic polarizers. Our dichroic plate beamsplitters are manufactured with a special design and proprietary manufacturing approach, allowing us to attain steep edges and flat, high reflection and transmission bands.
The almost complete transmission and reflection provided by our dichroic polarizers means that very little stray light gets through the imaging system. This results in high contrast image and a very good signal to noise ratio, as compared to other polarizers.
Our dichroic polarizers feature a UV grade fused silica, JGS1, or JGS2 substrate, coated with a hard dielectric coating. These glass polarizers have a much higher damage threshold than their plastic counterparts, and are suitable for precision applications. Our coatings fully meet MIL-STD-810F and MIL-C-484971 requirements, and we have a variety of different options available to meet your wavelength range.
Applications of dichroic polarizers include genomics, proteomics, and fluorescence microscopy. These beamsplitters can be utilized whenever beam combination, beam separation, or multispectral detection is required, and can be used as bandpass filters to cover several colors. Used in combination with our shortpass filters, they can create custom narrow bandpass filters.
Circular polarizers are not a different type of polarizer, but simply the combination of a quarter waveplate with a linear dichroic polarizer. The two pieces are carefully aligned to work together perfectly. Light is polarized as it passes through the polarizer plate, and then transformed by the waveplate into circularly polarized light. The electric field of this circularly polarized light can be considered to consist of two separate linear components perpendicular to each other, with a phase difference of pi/2. Since these polarizers are manufactured in one piece no alignment is necessary. Circular polarizers have applications in imaging, microscopy, and intensity adjustment. They are often used to reduce flare while imaging.
High contrast glass linear polarizers are dichroic plate polarizers which provide a high extinction ratio, up to 10,000:1 for 400-700 nm. These thin film polarizers have anti reflective coatings to minimize light loss, and are suited to a wide variety of industrial or scientific usage.
Polarizing cube beamsplitters are manufactured of two right angle prisms. These prisms are cemented together at the hypotenuse, forming a cube. They hypotenuse of one of the cubes features a dielectric coating, and AR coatings are typically applied to each square face of the beamsplitter.
Birefringent polarizers are manufactured from two crystalline prisms mounted together. The angle of the prisms will depend on the application desired. These crystalline polarizers typically have high damage thresholds.
A Glan-Taylor prism is another type of polarizing beam splitter. It is formed of two right angled prisms mounted together, separated on their long face by an air gap. Incident light travels through a short side into hypotenuse side of the first prism, and s-polarized light is reflected at the internal air-gap. P-polarized light continue through the prism. These polarizing prisms are typically used when high polarization purities, high extinction ratios, or broad spectral ranges are key. They can be used for visible, UV, or NIR applications.
A wire grid polarizer is manufactured from many very thin, parallel wires. Only light with a polarization perpendicular to the wires will be transmitted; other light is reflected. Wire grid polarizers are a versatile option that offers good environmental stability.
Shanghai Optics produces a wide variety of high quality glass polarizers, carefully tooled to minimize wavefront distortion. Contact us for manufacturing limit or custom specifications.