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Acousto-optic modulator (AOM)

Deflects and frequency-shifts first-order light with efficiency, zero-order, and square or sinusoidal RF modulation.

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In the real world

An AOM diffracts light off a traveling sound wave launched into a crystal by a piezoelectric transducer driven at an RF frequency. In the Bragg regime, light incident at the Bragg angle diffracts efficiently into a single order, shifted in frequency by exactly the drive frequency (up-shifted or down-shifted depending on propagation direction relative to the sound wave):

sinθB=λ2Λ,Λ=vsfRF\sin\theta_B = \frac{\lambda}{2\Lambda}, \qquad \Lambda = \frac{v_s}{f_{RF}}
Bragg angle, set by the acoustic wavelength Λ (sound velocity vₛ over drive frequency).
fout=fin±fRFf_{\text{out}} = f_{\text{in}} \pm f_{RF}
The diffracted beam is frequency-shifted by exactly the RF drive frequency.

In OpticalSetup

The frequency shift is modeled exactly: the diffracted ray's optical frequency is genuinely shifted by the configured RF frequency, then converted back to a wavelength, which is what makes an AOM in a pulse-timing setup actually change color. Deflection and diffraction efficiency, though, are direct configurable parameters rather than quantities derived from crystal or drive properties. Gating support (square or graded sinusoidal) lets the modeled RF drive turn on and off in time, which the pulse-timing overlay reads as a temporal gate on the beam.

Simplified vs. reality

Deflection angle and diffraction efficiency are set directly by you, not derived from the Bragg condition, RF power, or interaction length — this is a schematic acousto-optic model, not a Bragg-cell simulator. Only the frequency shift is first-principles physics.

Related components

Further reading