Y6T65 distinguish self-focusing and self-phase modulation effect
Often referred to in textbooks sentence: When a bright field incident medium, such that the refractive index of the medium is changed, i.e., coupled and nonlinear refractive index, the light intensity related to the refractive index of refraction outside the original linear of light can be generated from the phase modulation and self-focusing phenomenon of propagation in the medium
Our optical communication medium is a silica, i.e. quartz, glass or call
Self-focusing, it is because their own reasons, resulting in the phenomenon of beam polymerization
The phenomenon of self-phase modulation phase modulation, is due to their own reasons, resulting in the
Self-focusing and self-phase modulation, are due to its own reasons, resulting in a change in refractive index, the focus is generated or phase modulation phenomenon.
1. Start with a refractive index
2. Besides refractive optical power and
3. Then talk generated optical power distribution is self-focusing phenomenon which state
4. See corresponding to the optical power distribution of the self phase modulation is a state which
5. Finally, take a look at a similar phenomenon
Refractive index, when Y5T54 write current to the refractive index, mentioned
Light in a vacuum, i.e. without any space medium speed of 300,000 km per second
Once the light enters the medium, the medium is a substance molecules are composed according to a certain structure, such as an optical fiber, the main material is silicon dioxide, such as silicon waveguide, the main material is silicon ....
On a microscopic scale, the light encounters the molecule, its speed will come down, barrier encountered to find a new transmission path bypassing
Physics, on optical propagation velocity in the medium, is defined to be
The refractive index of the medium, that is, than the vacuum speed of light and medium speed
A relationship between the refractive index of the first, is caused by the molecular structure of the material
Big impact on the molecular speed of light, the speed of light is low, a large refractive index
Small molecule light barrier, high speed of light,
The second refractive index relationship, caused by the light itself
The more dense the photons, the lower the rate in the medium
This is a common refractive index of the equation, I have to be split, n0, is determined by the medium itself, the barrier of the speed of light
Behind the block, is the optical power density (light own degree of aggregation) determined, also affect the speed of propagation of light
Self-focusing and self-phase modulation, it is a later discussion
Distribution of the light field, intermediate or power density, low density on both sides, with a transmission signal, in fact, different speeds
In the middle of faster and slower speed on both sides, relatively speaking, to be faster, first passed in front of the photons will conquer new media space because the media is not light, the refractive index of smaller
After some distance transmission, it is produced as a lens, focusing of
Self-phase modulation changes the speed of light, but also due to the distribution of the light power generated
In optical fiber transmission, for example, a binary optical amplitude modulation information, is the size of the optical power of the signal to characterize, a large power is expressed as "1", a small power is represented as "0"
Power, will affect the refractive index, will affect the speed of light, the FIG., Different transmission speeds since the signal 10, produces the intersymbol interference, the signal transmission delay (phase) is different called self-phase modulation.
A similar phenomenon, Y5T291 / 293 four-wave mixing, other wavelength optical signal change of the refractive index profile, leading to effects on other wavelengths. Cross-phase modulation, the principle is similar.
The last sentence, these phenomena are a great optical power density generated by these nonlinear effects that can not be ignored, have an impact on the quality of the transmission system, only need to pay attention and resolve.
