Are there any applications where a laser can be more effectively substituted with a maser?

 

 

Interesting question. I know a fair bit about lasers and almost nothing about masers apart from their use as atomic clocks, communications, radar etc. I suppose the most obvious difference is wavelength. Lasers cover the near IR to x-Ray region of the EMS whilst masers are in the microwave region.

I depends on what you want to do with it. As Griffon mentions, masers are used as clocks. It is only recently that lasers were able to function in a similar way, so masers were more effective. They still are, in terms of continuously-running clocks (i.e. actual clocks and not frequency standards)

What's your interest, Petrushka?

The ratio of the frequencies is like 10⁵. Is there any application that could use both?