High-energy, single longitudinal mode hybrid laser

Claim 1

In a hybrid laser comprised of two spaced reflectors forming a given resonant cavity capable of supporting wave energy within a certain frequency band, and a relatively wide aperture, high-energy active lasing medium and a relatively narrow aperture, low-energy active lasing medium situated in serial relationship with one another within said given resonant cavity, said high-energy active lasing medium having a first bandwidth within said certain frequency band which first bandwidth is sufficiently wide to support a plurality of longitudinal oscillation modes of said wave energy and said low-energy active lasing medium having a second bandwidth within said first bandwidth which is sufficiently narrow to support only a single one of said plurality of longitudinal oscillation modes of said wave energy; the improvement wherein said hybrid laser further comprises: means for achieving high energy in a single longitudinal mode from said hybrid laser, said means including a Galilean telescope situated within said given resonant cavity and located in between said low-energy active lasing medium and said high-energy active lasing medium (1) for concentrating the wave energy emerging from said high-energy active lasing medium and traveling in a direction from said high-energy active lasing medium toward said low-energy active lasing medium from the relatively wide aperture occupied thereby in said high-energy active lasing medium to the relatively narrow aperture occupied thereby in said low-energy active lasing medium and (2) for expanding in size the wave energy emerging from said low-energy active lasing medium and traveling in a direction from said low-energy active lasing medium toward said high-energy active lasing medium from the relatively narrow aperture occupied thererby in said low-energy active lasing medium to the relatively wide aperture occupied thereby in said high-energy active lasing medium.