We consider a large class of optical cavities and gain media with an off-axis external feedback which introduces a two-point nonlocality. This nonlocality moves the lasing threshold and opens large windows of control parameters where weak light spots can be strongly amplified while the background radiation remains very low. Furthermore, transverse phase and group velocities of a signal can be independently tuned and this enables us to steer it nonmechanically, to control its spatial chirping, and to split it into two counterpropagating ones.
|Number of pages||5|
|Journal||Physical Review Letters|
|Publication status||Published - 9 Aug 2007|
- signal amplification
- optical cavities
- off-axis feedback