Wire Grid Polarizers are an important application of optics, which can be defined as an array of thin metal wires (lines) closely spaced that is placed above the transparent substrate. Since the wire grid acts as an absorptive polarizer, the light consistently passes through the oscillating wires. These polarizers feature a number of benefits such as high extinction ratios, operating temperatures, high transmission, and broad bandwidth ranges. As compared to conventional Polarizers, this type offers excellent heat resistance and durability.
Functions of Wire Grid Polarizers:
- One of the common functions of wire grid polarizers is to polarize radiation from an unpolarized molecular laser.
- Attenuate radiation from a polarized laser or to polarize and attenuate a laser beam together.
- Wire Grid Polarizers can be inserted in the reflected beam in order to polarize beam splitter.
- They are also used in several reflectance accessories for building the dispersive and FT-IR spectrophotometers.
- During investigating metal surfaces and crystal structures, wire grid polarizers can be used to polarize the incident radiations.
- It acts as an optical filter that allows the light waves of a specific polarization pass through while blocking other light waves.
Performance Determining Factor: The key factor that determines the performance of a wire grid polarizer is the relationship between the parallel grid elements and the wavelength of the incident radiation.
After determining the relationship, two major implications are:
- As compared to the wavelength, if the grid spacing is large, the grid functions as a diffraction grating. In this case, the gird diffracts both polarizations according to the operating principle.
- When the grid spacing or period is shorter than the wavelength, the grid functions as a polarizer. In this case, the polarizer reflects electromagnetic radiation on the grid elements and transmits radiation of the orthogonal polarization.
Application of Wire Grid Polarizers: Polarizers find its application in several giant industries such as:
- They are used in many optical techniques and instruments such as laser optics, illumination, and high lumen projector.
- It is also used in several devices that fall under photography and LCD technology.
- They are also used in appliances such as measurement systems, microwaves, imaging systems, and X-rays.
Wire Grid Polarizers are used in several areas of modern optics and optical products. However, factors like high conductivity, tensile strength, and efficient capabilities have pushed its application in various devices.