Polarizer, also known as PL lens, is a type of color filter. The primary function of a polarizer is to selectively pass light with a certain polarization direction. Polarizers are frequently used in color photography or black-and-white photography to eliminate or reduce bright light reflected by non-metal surfaces and hence to remove or reduce bright spots. For example, in the scenery and landscape photography, polarizers are used to show the object texture in a bright reflection area, to highlight the scene behind glass, and to darken sky and to show blue sky and white clouds, etc. Based on the principle for filtering polarized light, polarizers may be divided into two types, circular polarizers (CPL) and linear polarizers (LPL).
One example of a polarizer is a slice of directional micro-polarizing crystal (such as mica) laminated between two pieces of optical glass. Another example of a polarizer is to coat the optical glass with a crystal material such as a polyethylene film or a polyethylene cyanide film. Such polymer coating produces a fine grating structure, like a fine fence, only passing light with a polarization direction same as the slit direction of the grating structure. The two pieces of glass are mounted independently on a rotatable ring, and rotating one of the two glass may eliminate polarized light reflected from the surface of the photographed object. However, as time goes by, the polymer coating gradually gets aged and loses the polarizing function. In addition, moisture, shock, and vibration also shorten its lifespan.
The disclosed polarizer and fabrication method are directed to solve one or more problems in the art.