Re: combining laser beams

[Herbert H Gottlieb <herbgottlieb@JUNO.COM>]

On Wed, 11 Dec 2002 10:13:12 -0500 "Carl E. Mungan" <mungan@USNA.EDU>
writes:
> I have been thinking about the following question. I would be very
> interested to hear some of the listmembers' thoughts.
>
> To what extent can one combine beams from separate lasers into a
> single beam?

*** Combining them is easy .... that is unless we also want their
outputs to be locked in phase with each other. With each laser beam
producing its crests and troughs at a different time from that of
the others a creation of wild interference  patterns will be observed
as they form alternate constructive and destructive interference patterns
with the outputs of the other lasers.



> Specifically: what system of optics might one use to do the combining?

*** This would be an optics designer's nightmare hat might take her
entire life without ever being finiszhed. At minimum, it would require
mirrors, lenses, and synchronized output lasers.Perhaps pulsed lasers
with high outputs would be used .

> * assuming the lasers are not synchronized, what issues of


> coherence
> and interference might arise?
> * given some measure of the beam quality of the input beams
> (perhaps
> M^2 or some other description of the occupation of the various TE
> and
> TM modes), what is the theoretical best possible quality of the
> output beam?
>
> Any pointers to specific references (preferably including page
> numbers) would be greatly appreciated. (But random thoughts off the
> top of one's head can also be helpful.) Carl
> --
> Carl E. Mungan, Asst. Prof. of Physics  410-293-6680 (O) -3729 (F)
>        U.S. Naval Academy, Stop 9C, Annapolis, MD 21402-5026
> mungan@usna.edu    http://physics.usna.edu/physics/faculty/mungan/