# What is a floquet (optical) sideband?

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1. Jan 8, 2016

### taishizhiqiu

In literature, I read:"(exposed in a beam of light) in floquet theory, the quasi-static eigenvalue spectrum at finite driving field A shows copies of the original bands shifted by integer multiples of $\Omega$, the so-called Floquet sidebands"

I have read something about floquet theory and found out that quasienergy is uncertain by integer multiples of $\hbar \Omega$. However, I cannot understand why quasienergy band should be the shape of original band.
Can anyone help me?

2. Jan 13, 2016