Q-switch for synchronizing mode-locked laser pulse trans with external events

Claim 2

In a laser capable of oscillating at a given frequency, a light shutter within the laser and in the path of oscillating light including a gaseous vapor whose molecules or atoms are highly absorptive of said given frequency so as to prevent lasing during pumping of said laser, an electrical energy storing mechanism adapted to store an energy having a value capable of dissociating or ionizing said molecules or ionizing said atoms so that said vapor becomes transparent to such frequency, and a switch interposed between said electrical energy storing mechanism and said gaseous vapor, the closing of which permits such electrical energy storing mechanism to discharge through said gaseous vapor so as to dissociate or ionize said frequency-absorbing molecules or atoms, respectively, and initiate lasing at said frequency.

Claim 3

In a laser capable of oscillating at a given frequency, a light shutter comprising an electrical discharge tube housing a metal vapor absorptive of said given frequency, means for heating said gaseous vapor to a predetermined temperature so that the latter is maintained in a gaseous state, a charge storing mechanism in electrical contact with said tube and adapted to store a charge below the self-flash voltage of said gaseous vapor, and means for injecting a laser beam through said gaseous vapor so as to trigger an ionization path in said gaseous vapor whereby said charge storing mechanism is discharged through said ionization path, creating a plasma which does not attenuate said frequency.

Claim 4

In a laser capable of oscillating at a given frequency, a light shutter comprising an electrical discharge tube housing a metal vapor absorptive of said given frequency, means for heating said gaseous vapor to a predetermined temperature so that the latter is maintained in a gaseous state, a charge storing mechanism in electrical contact with said tube and adapted to store a charge below the self-flash voltage of said gaseous vapor, and means for injecting a laser beam through said gaseous vapor so as to trigger an ionization path in said gaseous vapor whereby said charge storing mechanism is discharged through said ionization path, creating a plasma which does not attenuate said frequency.

Claim 5

The structure of claim 2 wherein said gaseous vapor is cesium.

Claim 6

The structure of claim 2 wherein said gaseous vapor is rubidium.

Claim 7

In a laser capable of oscillating at a given frequency, a light shutter including an electrically conductive conduit containing a metal vapor absorptive of said given frequency, a neodymium rod within said cavity, optical pump means for pumping said neodymium rod, a mode-locking element in said cavity for producing a train of pulses when said rod lases, means for heating said gaseous vapor to a predetermined temperature so the latter is maintained in a gaseous state, an electrical charge storing mechanism in electrical contact with said tube and adapted to store a charge below the self-flash voltage of said gaseous vapor, and means for injecting an external laser beam through said gaseous vapor so as to trigger an ionization path in said gaseous vapor so that said charge-storing mechanism is discharged through said ionization path, creating a plasma which does not attenuate said given frequency so that said neodymium rod lases, said gaseous vapor becoming absorptive again of said given frequency when the atoms of said gaseous vapor plasma reassociates to its normal equilibrium ratio of atoms to molecules.

Claim 8

In a laser capable of oscillating at a given frequency, a light shutter including an electrically conductive conduit containing a metal vapor absorptive of said given frequency, a neodymium rod within said cavity, optical pump means for pumping said neodymium rod, a mode-locking element in said cavity for producing a train of pulses when said rod lases, means for heating said gaseous vapor to a predetermined temperature so the latter is maintained in a gaseous state, an electrical charge storing mechanism in electrical contact with said tube and adapted to store a charge below the self-flash voltage of said gaseous vapor, and means for injecting an external laser beam through said gaseous vapor so as to trigger an ionization path in said gaseous vapor so that said charge-storing mechanism is discharged through said ionization path, creating a plasma which does not attenuate said given frequency so that said neodymium rod lases, said gaseous vapor becoming absorptive again of said given frequency when the atoms of said gaseous vapor plasma reassociates to its normal equilibrium ratio of atoms to molecules.

Claim 9

A laser capable of emitting a train of mode-locked pulses at a given frequency, a gaseous vapor contained within a housing within said laser, said vapor being highly absorptive of lasing energy at said given frequency, means for applying a stored charge to said housing which is below the self-flash voltage of said gaseous vapor, a laser amplifier capable of amplifying said mode-locked laser pulses, means for triggering said vapor into ionization so as to discharge said stored charge through said vapor so as to ionize the latter into a plasma which does not attenuate lasing energy at said frequency, said time of forming said non-absorbing plasma having a value of t microseconds, and means for actuating said laser amplifier at a time t microseconds after triggering said laser so that said train of mode-locked pulses can be amplified by said laser amplifier.

Claim 10

A laser capable of emitting a train of mode-locked pulses at a given frequency, a gaseous vapor contained within a housing within said laser, said vapor being highly absorptive of lasing energy at said given frequency, means for applying a stored charge to said housing which is below the self-flash voltage of said gaseous vapor, a laser amplifier capable of amplifying said mode-locked laser pulses, means for triggering said vapor into ionization so as to discharge said stored charge through said vapor so as to ionize the latter into a plasma which does not attenuate lasing energy at said frequency, said time of forming said non-absorbing plasma having a value of t microseconds, and means for actuating said laser amplifier at a time t microseconds after triggering said laser so that said train of mode-locked pulses can be amplified by said laser amplifier.