1, the wavelength of the light source must be much larger than the size of the diffraction hole. This is a necessary condition for fraunhofer diffraction, because only in this way can the diffraction hole be regarded as a point source and the diffraction effect produced by the light source shining on the diffraction hole be regarded as the interference of multiple wavelet sources.
2. The diffraction aperture must be much smaller than the wavelength of the light source. This is to ensure that the diffraction hole can produce obvious diffraction effect. If the size of the diffraction hole is equivalent to the wavelength of the light source, the diffraction effect is no longer obvious.
3. The distance between light source and diffraction hole must be much longer than the wavelength of light source. This is to ensure that diffraction holes can be regarded as point sources. If the distance between the light source and the diffraction hole is too close, then the diffraction hole cannot be regarded as a point light source, and the diffraction effect will be affected.
4. The screen for observing diffraction phenomenon must be far enough. This is to ensure that the diffraction pattern can be clearly observed. If the screen is too close, the diffraction pattern may not be clearly presented.
Flawn Hoffer's knowledge.
1, Flawn Hof is a German physicist and astronomer who is famous for discovering the basic principle of spectroscopy. Before 1800, Flawn Hof discovered many important spectral phenomena through experiments and made a systematic study of spectroscopy.
2. One of the most important discoveries of Flawn Hof is the concept of spectral line. He found that when light passes through the slit, it will form a bright line, which will later be called Fraunhofer line. These lines are formed by light of specific wavelength emitted by different elements or compounds, which constitute the unique "fingerprint" of each substance.
Fraunhofer also studied the diffraction and interference of light. He found that when light passes through the slit, it will form a bright diffraction stripe, which is caused by the interference of light waves at the edge of the slit. This discovery laid the foundation for the later optical research and application.
In addition to his contributions in the field of optics, Fraunhofer also made important contributions to astronomy and physics. He improved the design of the telescope and invented the reflective telescope, which can measure the position and motion of celestial bodies more accurately. In addition, Fraunhofer also improved the measurement methods of current and electric quantity, and made contributions to the study of electricity.