Polarised light microscopy and the use of polarised light in everyday life
Principle of Polarisation
In layman's terms, natural light is a transverse wave that vibrates in all directions. A grating is placed in front of the light, and this grating only allows light that vibrates in a certain direction to pass through, so the light that passes through the grating is polarised light.
A polarising microscope is a microscope used to study so-called transparent and opaque anisotropic materials. Substances with birefringence can be distinguished clearly under a polarising microscope. Of course, these substances can also be observed by staining, but in some cases this is not possible and a polarising microscope must be used. Polarizing microscope is a necessary instrument for the research and identification of birefringent substances by using the polarization property of light, and it can be used for single polarized light observation, orthogonal polarized light observation, and conical light observation by the majority of users.
Application Fields:
Geology and mineral analysis: such as the analysis of minerals and crystals.
Biological field: In living organisms, different fibre protein structures show obvious anisotropy, using polarized light microscope can get the details of molecular arrangement in these fibres. For example, collagen, spindle humour filaments during cell division.
Identification of various biological and non-biological materials: e.g. identification of starch properties, identification of pharmaceutical ingredients, fibres, liquid crystals, DNA crystals, etc.
Medical analysis: such as stones, uric acid crystal detection, arthritis, etc.
Polarised light application-automobile lights
Cars travelling on the highway at night and the opposite side of the vehicle encounter, in order to avoid the glare of the lights of both sides, the driver are off the headlights, only open the small lights, slow down the speed, in order to avoid a car accident. If the front window glass of the driver's cab and the glass cover of the lamps are equipped with a polarising film, and the provisions of their polarisation direction are along the same direction and at an angle of 45 degrees with the horizontal plane, then the driver from the front window can only see from their own lamps issued by the light, and can not see the opposite side of the lamps of light, so that the car is driving at night, do not turn off the lights, and also do not decelerate, you can ensure that ** line driving.
Application of polarised light - stereoscopic film
In the shooting of three-dimensional film, with two cameras, two camera lenses are equivalent to two eyes, they were shot at the same time the same object of the two images, the projection of the two images at the same time on the screen. If you try to make the audience's one eye can only see one of the picture, you can make the audience get a sense of three-dimensional. For this reason, in the projection, two projectors each projector lens to put a polarizer, two polarizers polarization direction perpendicular to each other, the audience to wear glasses made of polarizer, the left eye polarizer polarization direction and the left side of the projector on the same direction of polarisation, the right eye polarizer polarization direction and the right side of the projector on the same direction of polarisation, so that the two images on the screen through two eyes, respectively The two images on the screen are observed by the two eyes, and a stereoscopic image is formed in the human mind.
Polarising microscope
Polarising microscope is a type of microscope used to study so-called transparent and opaque anisotropic materials, which has important applications in geology and other scientific disciplines. Any birefringent material can be clearly distinguished under a polarising microscope, and a reflecting polarising microscope is an essential instrument for the study and identification of birefringent materials using the polarising properties of light.
