# How to maximize the modulation depth?

Suppose I am modulating a laser beam of a particular wavelength using AOMs. How do I ensure that I have achieved 100 % or the maximum possible modulation depth? My laser is 80 MHz rep rate laser and I am modulating it at a much lower frequency say 1MHz. I can observe the beats using a oscilloscope though.

## 1 Answer

The modulation depth is a parameter that depends on your device and sometimes there is an option to control it manually. But when using a device reading the catalog can help you to find device's parameter such as modulation depth.

In a practical manner: The modulation depth, $M_d$ was then calculated at each ultrasound pressure using:

$$M_d=\frac{{modulated},{light}}{{total},{intensity}, {light}}$$

modulation depth was also linearly proportional to the squared ultrasound pressure.

• Could you please expalin that how can I calculate the modulation depth using a oscilloscope? Sep 16 '18 at 3:02