[alfa015 (OP)]

Hello. I have been lately thinking about the possibility of aliens using lasers instead of radio telescopes to contact us. Lasers seem to be more efficient than radio telescopes because they focus the power into a more narrow beam, which makes a pulse to be more detectable. Moreover, a laser signal would make a star appear thousands of times brighter. An extraterrestrial civilization could use lasers of visible light or infrared light, which is usually not visible. The main advantage of infrared light is that it penetrates through interstellar gas and dust better than visible light. I actually made a collaboration with Isaac Arthur explaining my opinion:

[Link to personal you-tube channel removed]

Do you think aliens would use laser instead of radio telescopes to attempt contact?

[evan_au]

Yuri Milner also thinks lasers are a possibility for interstellar communications.

He is funding an optical  telescope to scan nearby stars for laser activity - presumably while it is doing its primary role of looking for planets using the optical Doppler method.
See: https://en.wikipedia.org/wiki/Automated_Planet_Finder#Collaboration_with_Breakthrough_Listen

The directionality of lasers is both a blessing and a curse - it can target a particular star with high power - but any hypothetical observers have to be looking in exactly your direction, exactly when your laser signal arrives.
- In the meantime we are beaming random radio signals in every direction, continually...