Technique for amplifying two or more laser beams in a single laser amplifier

Apparatus for amplifying two or more laser input pulses, said laser input pulses consisting of at least a first and second laser input pulse, in a single laser amplifier system comprising an active laser medium, spaced apart optics defining the path of said input pulses through said active laser medium, active laser medium excitation means operatively associated with said active laser medium to create the population inversion for said first laser input pulse, said first laser input pulse creating the population inversion in said active laser medium for said second laser input pulse, comprising:

• means for producing said first and second laser input pulses,
• means for controlling the entry of said first and second laser input pulses into active laser medium of said laser amplifier system such that said first laser input pulse precedes said second laser input pulse by a time which is greater than the time required for rotational relaxation in order to permit the generation of the population inversion in said active laser medium for said second laser input pulse but less than the time required for loss of said population inversion due to vibration relaxation,
• means for exciting the active laser medium of said laser amplifier system at a time when the population inversion in said active laser medium is about maximum for at least one of the laser transitions of said laser input pulses, and
• means for adjusting the relative intensities of the first and second laser input pulses to avoid absorption of the final portion of said pulses thereby providing amplification of essentially the total first and second laser input pulses.

A method for amplifying two or more laser input pulses, said laser input pulses consisting of at least a first and second laser input pulse, in a single laser amplifier system comprising an active laser medium, spaced apart optics defining the path of said input pulses through said active laser medium, laser excitation means operatively associated with said active laser medium to create the population inversion for said first laser input pulse, said first laser input pulse creating the population inversion for said second laser input pulse, comprising the steps of,

• controlling the entry of said first and second laser input pulses into said active laser medium of said laser amplifier system such that said first laser input pulse precedes said second laser input pulse by a time sufficient to permit the generation of the population inversion in said active laser medium for said second laser input pulse, said time being less than the time required for loss of said population inversion by vibrational and rotational relaxation,
• exciting the active laser medium of said laser amplifier system at a time when the population inversion in said laser medium is about maximum for at least one of the laser transitions of said laser input pulses, and
• adjusting the relative intensities of the first and second laser input pulses to avoid absorption of the final portion of said pulses thereby providing amplification of essentially the total first and second laser input pulses.

Apparatus for amplifying two or more laser input pulses, said laser input pulses consisting of at least a first and second laser input pulse, in a single laser amplifier system comprising an active laser medium, spaced apart optics defining the path of said input pulses through said active laser medium, laser excitation means operatively associated with said active laser medium, laser excitation means operatively associated with said active laser medium to create the population inversion for said first laser input pulse, said first laser input pulse creating the population inversion for said second laser input pulse, comprising,

• means for controlling the entry of said first and second laser input pulses into said active laser medium of said laser amplifier system such that said first laser input pulse precedes said second laser input pulse by a time sufficient to permit the generation of the population inversion in said active laser medium for said second laser input pulse, said time being less than the time required for loss of said population inversion by vibrational and rotational relaxation,
• means for exciting the active laser medium of said laser amplifier system at a time when the population inversion in said laser medium is about maximum for at least one of the laser transitions of said laser input pulses, and
• means for adjusting the relative intensities of the first and second laser input pulses to avoid absorption of the final portion of said pulses thereby providing amplification of essentially the total first and second laser input pulses.