A metal wire grid polarizing beam splitter is an optical element that uses a metal wire grid structure to separate the polarization states of light, and is widely used in fields such as optical communication and laser processing.
Usually composed of a metal wire grid polarizer array sandwiched between two right angled prisms. Metal wire grids are generally made of good conductor materials such as aluminum, gold, silver, etc. The wire grid is accurately fabricated on a transparent substrate, and two right angled prisms sandwich the substrate with the wire grid in the middle, forming a cubic structure. Each side of the spectroscope is usually coated with an anti reflective film to reduce surface reflection.
When the wavelength of the incident light is greater than the spacing of the metal wire grid, polarized light with an electric vector perpendicular to the metal wire grid can pass through the grid, while polarized light with an electric vector parallel to the metal wire grid will be reflected, thereby achieving the decomposition of unpolarized or mixed polarized light into two orthogonal linearly polarized light beams.
Performance Characteristics
Wide band compatibility: By optimizing the grating period and material selection, it can cover the visible to mid infrared wavelength range. For example, some products can support laser wavelengths from 405nm to 1550nm.
Characteristics of high incidence angle: It can maintain good polarization performance over a large range of incidence angles, such as the metal wire grid polarizing beam splitter of Yunxiang Optoelectronics, which can maintain a certain contrast within a large cone angle of ± 25 °.
High extinction ratio: It has a high transmittance extinction ratio and can effectively separate light of different polarization states.
High power tolerance: The metal wire grid polarizing beam splitter using optical glue technology can withstand kW level laser power and is suitable for high-power laser systems.
Application field
Optical communication system: used for polarization state multiplexing, doubling the transmission capacity of a single optical fiber, and can also be used as a pump multiplexer to reduce the polarization sensitivity of optical amplifiers.
Laser processing: In ultrafast laser systems, circularly polarized light is decomposed into linearly polarized light to optimize beam quality and reduce the heat affected zone during processing.
Quantum computing: In photon entanglement experiments, its high extinction bit rate ensures accurate manipulation of quantum states and reduces error rates.
Biological imaging: In multiphoton microscopy, separating excitation light and fluorescence signals improves imaging signal-to-noise ratio.