Laser amplifier with variable gain control

Claim 1

A LASER AMPLIFIER CONSTRUCTION COMPRISING A THIN ELONGATED COMPONENT FORMED OF A TRANSPARENT MATERIAL OF A PREDETERMINED REFRACTIVE INDEX AND INCLUDING AN ACTIVE LASER INGREDIENT THEREIN, SAID COMPONENT HAVING AN OPTICALLY FINISHED FLAT END SURFACE FORMED ON THE ENTRANCE END THEREOF FOR ADMITTING INTO SAID COMPONENT OPTICAL SIGNALS TO BE AMPLIFIED, SAID COMPONENT HAVING A SECOND OPTICALLY FINISHED FLAT END SURFACE FORMED ON THE OPPOSITE EXIT END THEREOF FOR ALLOWING SAID OPTICAL SIGNAL AFTER AMPLIFICATION TO PASS OUTWARDLY THERETHROUGH, OPTICAL PUMPING MEANS POSITIONED ADJACENT IN EXTENDED INTERMEDIATE PORTION OF SAID LESSER COMPONENT FOR PRODUCING AN INVERSION IN POPULATION THEREIN AND A GAIN IN AMPLIFICATION IN OPTICAL SIGNALS PASSING THERETHROUGH, SIGNAL DETECTING MEANS DISPOSED SUBSTANTIALLY IN AXIALLY ALIGNED SPACED RELATION TO THE EXIT END OF SAID COMPONENT SO AS TO RECEIVE OPTICAL ENERGY AND INCLUDING SAID AMPLIFIED SIGNALS, AND LIGHT-COLLECTING AND RE-DIRECTING MEANS DISPOSED IN SPACED RELATION TO THE EXIT END OF SAID COMPONENT AND IN SUCH OFFSET RELATION TO AN OPTICAL AXIS EXTENDING BETWEEN SAID EXIT END AND SAID DETECTING MEANS AS TO INTERCEPT OFF-AXIS OPTICAL ENERGY BEING EMITTED FROM SAID EXIT END DURING SAID SIGNAL AMPLIFICATION, SAID LIGHT-COLLECTING AND RE-DIRECTING MEANS INCLUDING CONCAVELY CURVED MIRROR MEANS SO ANGULARLY POSITIONED RELATIVE TO SAID EXIT END AS TO DIRECT AT LEAST A PART OF THE OPTICAL ENERGY RECEIVED THEREBY BACK INTO SAID COMPONENT THROUGH SAID EXIT SURFACE FOR EFFECTING A CONTROL AS TO THE GAIN IN THE OPTICAL SIGNAL AMPLIFICATIONG BEING PROVIDED BY SAID COMPONENT.