What Happens When Two Wavelengths Are Modulated at the Same Frequency?

[MS1984]

hi

what would happen if i modulated two wavelengths with the same intensity modulation frequency?

for example if i had 2.0um light and 1.5um light and modulated them both with the same frequency, would sidebands develop around each wavelength? or would they interfer in a more complicated way, giving a more complex sideband structure?

thanks, let me know if you need me to clarify this at all

 

[mikeph]

Unless you have some nonlinear optical effects I don't see how they would interfere at all. The spectra of each individual modulated signal should just add, no?

 

[Baluncore]

If the light is amplitude modulated by a sine wave, then each carrier would have a side band on each side. There would be no interaction between those carriers or their sidebands. That is so long as the modulation frequency was not so high that the sidebands overlapped.

This is the same signal scenario as the AM radio band.

 

[meBigGuy]

for example if i had 2.0um light and 1.5um light and modulated them both with the same frequency, would sidebands develop around each wavelength?

Yes, just like any other amplitude modulated signal.

or would they interfer in a more complicated way, giving a more complex sideband structure?

No, just like any other amplitude modulated signal.

This of course assumes the system is completely linear. The waves cannot interact in a linear system other than interference pattern like effects.

 

[pmacias]

Dual wavelength modulation refers to the process of modulating two different wavelengths of light with the same intensity modulation frequency. This can result in the development of sidebands around each wavelength, as well as interference between the two wavelengths, leading to a more complex sideband structure.

The specific outcome of this modulation will depend on the specific properties of the two wavelengths and how they interact with each other. It is possible that the sidebands will develop independently around each wavelength, or they may interfere with each other in a more complicated manner.

In general, dual wavelength modulation can be a useful technique for manipulating the properties of light and studying its interactions. It can also have practical applications in areas such as telecommunications and spectroscopy. Further research and experimentation would be needed to fully understand the effects of dual wavelength modulation and its potential uses.