Abstract

It is well known that a small amount of optical feedback can drastically affect the emission properties of a laser. Semiconductor lasers, in particular, have been studied extensively for the effects of optical feedback. For such lasers, depending on the strength of the feedback and length of the external cavity, the intensity noise and linewidth can be either increased or decreased by orders of magnitude. Recently, attention has been paid to the case for which the feedback comes from a phase- conjugate mirror. Such phase-conjugate feedback can produce novel behavior in both semiconductor lasers^1,2 and argon lasers. In the case of argon lasers, for example, it was reported that the intensity noise for frequencies below 1 MHz was reduced by more than a factor of 10 for an argon laser coupled to a phase-conjugating external cavity.

© 1993 Optical Society of America