A fiber-coupled acousto-optic modulator（https://www.cq-smart.com/fiber-optic-acousto-optic-modulator-aom-aofs） (FCAOM) manipulates light using sound waves. Here's a breakdown of how it works:
1.Light Input and Collimation: Light enters the FCAOM via an input fiber. This light is then collimated, meaning it's converted from a diverging beam into a parallel beam.
2.Acousto-Optic Crystal: The collimated light travels through a specially designed crystal within the FCAOM. This crystal is the core of the modulation process.
3.Sound Wave Interaction: An electrical signal is applied to a radio frequency (RF) driver. The driver generates sound waves that propagate through the crystal.
4.Light Diffraction: When light interacts with the sound waves in the crystal, it diffracts. Imagine waves gently bending around obstacles. The amount of diffraction depends on the intensity of the sound wave.
5.Light Focusing and Output: Finally, the diffracted light is focused into another fiber, the output fiber. By controlling the sound wave through the RF signal, the FCAOM modulates the light beam.
Here are some key points about FCAOMs:
Modulation Type: FCAOMs primarily function as intensity modulators. By varying the sound wave intensity, they can control the intensity of the output light beam.
Benefits: They can handle high optical power and offer a wide range of operational wavelengths. They are also useful for pulse picking and Q-switching applications in fiber lasers.
Challenges: There can be insertion loss (reduction in light intensity) due to coupling between the fibers and the crystal. Balancing efficient light collimation within the crystal and minimizing coupling losses is crucial for optimal performance.
