acousto-optic effect= it is the change in the refractive index of medium caused by mechanical production of acoustic-wave

If they are tunable, yes you can. If the operating frequency is locked, no, you cannot.

Markettechinc is an online source for tunable lasers. Another reputable company is Santec. This company also has an online presence where the tunable lasers are sold.

Tunable laser diodes measure the concentration of gases in an area. The advantages of tunable laser diodes is that they are able to detect very low levels of these gases.

Tunable lasers are commonly used for recording transmission data, or absorption information. In some applications, cooling is required, and tunable lasers are good for that use as well.