Using polarized light in daily life and using a polarizing microscope
Polarization principle
In layman's terms, natural light is a transverse wave, and the vibration direction is in all directions. A grating is placed in front of the light, and this grating only allows light vibrating in a certain direction to pass through, so the light passing through the grating is polarized light.
Polarizing microscopy is a type of microscope used to study so-called transparent and opaque anisotropic materials. Substances with birefringence can be clearly distinguished under a polarizing microscope. Of course, these substances can also be observed by staining, but some are not possible and must be observed using a polarizing microscope. Polarizing microscope is an essential instrument for research and identification of birefringent substances by using the polarization characteristics of light.
Application fields:
Geological and mineral analysis: such as the analysis of minerals and crystals.
Biological field: In living organisms, different fibrin structures show obvious anisotropy, and the details of the molecular arrangement in these fibers can be obtained by using a polarizing microscope. Such as collagen, spinning silk during cell division, etc.
Identification of various biological and non-biological materials: such as starch property identification, pharmaceutical composition identification, fiber, liquid crystal, DNA crystal, etc.
Medical analysis: such as stones, uric acid crystal detection, arthritis, etc.
Application of polarized light - car lights
When the car runs on the highway at night and meets the opposite vehicle, in order to avoid the glare of the lights on both sides, the driver turns off the headlights, only turns on the small lights, and slows down the speed of the vehicle to avoid accidents. If the front window glass of the cab and the glass cover of the car light are equipped with polarizers, and it is stipulated that their polarization directions are all along the same direction and at an angle of 45 degrees to the horizontal plane, then the driver can only see his own car through the front window. The light emitted by the lamp can not see the light from the lights of the opposite vehicle. In this way, when the car is driving at night, neither turn off the lights nor slow down, so as to ensure safe driving.
Application of Polarization - Stereoscopic Film
When shooting a three-dimensional movie, two cameras are used, and the lenses of the two cameras are equivalent to two eyes of people. They take two portraits of the same object respectively at the same time, and the two portraits are projected on the screen simultaneously during projection. If one of the eyes of the audience can only see one of the pictures, it will give the audience a three-dimensional effect. For this reason, during the projection, a polarizer is placed on each player lens of the two video players, and the polarization directions of the two polarizers are perpendicular to each other. The audience wears glasses made of polarizers, and the polarization direction of the left-eye polarizer is The polarization direction is the same as that on the left video player, and the polarization direction of the polarizer for the right eye is the same as that on the right video player. In this way, the two pictures on the screen are respectively observed by the two eyes and formed in the human mind. Stereoscopic images.
Polarizing microscope
Polarizing microscope is a kind of microscope used to study so-called transparent and opaque anisotropic materials. It has important applications in geology and other science and engineering majors. All substances with birefringence can be clearly distinguished under a polarizing microscope, and a reflection polarizing microscope is an essential instrument for researching and identifying substances with birefringence by using the polarization characteristics of light.
