HYBRID OPTICAL-RESONATOR TYPE LASER PROPOSED FOR DIRECT COUPLING INTOOPTICAL-FIBER

Combining one stable resonator with a concave mirror and a coupling-ho le plane mirror, and another unstable resonator having a concave mirro r and a convex mirror, a new hybrid optical resonator type laser has b een proposed by overlapping the concave mirror as a common one and fit ting the convex mirror exactly to the coupling-hole. Using the ABCD la w, the so-called g-parameters are first found for beam confinement. Th en, based on the eigen-equation, the field distribution on the piano-c onvex mirror is obtained with the g-parameters above. Knowing this fie ld distribution results in an effective transmittance I-e. Finally, th e ratio of the inner convex to outer plane mirror radii can be determi ned for an optimum coupling in both the limiting cases of homogeneousl y and inhomogeneously broadened gain media. Some numerical examples wi ll also be given for a CO2 laser having the proposed hybrid resonator.