Laser system moving electronically selectable gain

Claim 2

A laser system for selectively producing variable energy laser pulses at variable time intervals comprising: a. a laser cavity that includes a lasing medium; b. means for increasing the population inversion in said lasing medium to stimulate emission of a beam of energy therefrom; c. control means disposed within said laser cavity for selectively controlling both the energy level of respective output pulses and the time duration between successive pulses, said control means effective to deflect a fraction of said beam at a preselected angle responsive to application of ultrasonic power thereto, said fraction being a monotonic increasing function of said ultrasonic power; and d. logic circuitry connected to said control means for selectively applying said ultrasonic power at selected power levels to control the fraction of said beam deflected at said angle, said deflected fraction being reflected to provide energy feedback to said lasing medium, a laser output pulse being produced responsive to said reflected fraction lowering the lasing threshold of said cavity to a value below the level of population inversion in said lasing medium at that time, the energy of said pulse being defined by the amount that said lasing threshold is lowered below the population inversion level.

Claim 3

A laser system as set forth in claim 1 wherein said control means comprises an acousto-optic beam deflector operable to deflect radiation emitted by said lasing medium, the fraction of radiation from said laser medium that is deflected being proportional to the power applied to said deflector from said control means.

Claim 4

A laser system for selectively producing at random intervals laser pulses of variable energy comprising: a. a laser cavity that includeS a rod of lasing material between first and second reflecting means, said second reflecting means being positioned along a line that forms a preselected angle with the longitudinal axis of said laser rod; b. means for increasing the population inversion in said lasing material to stimulate emission of a beam of energy therefrom; c. an acousto-optic beam deflector disposed substantially along said longitudinal axis between said laser rod and said second reflecting means operable to selectively control the lasing threshold of said cavity, said deflector effective to deflect a fraction of said beam at said preselected angle response to application of ultrasonic power thereto, said fraction being a monotonic increasing function of said power, said deflected fraction defining the amount of energy feedback to said laser rod; and d. logic circuitry connected to said deflector for selectively applying said ultrasonic power at selected power levels to control the fraction of said beam deflected, thereby controlling the energy level of respective pulses and the time interval therebetween.

Claim 5

A laser system for selectively producing at random intervals laser pulses of variable energy comprising: a. a laser cavity that includeS a rod of lasing material between first and second reflecting means, said second reflecting means being positioned along a line that forms a preselected angle with the longitudinal axis of said laser rod; b. means for increasing the population inversion in said lasing material to stimulate emission of a beam of energy therefrom; c. an acousto-optic beam deflector disposed substantially along said longitudinal axis between said laser rod and said second reflecting means operable to selectively control the lasing threshold of said cavity, said deflector effective to deflect a fraction of said beam at said preselected angle response to application of ultrasonic power thereto, said fraction being a monotonic increasing function of said power, said deflected fraction defining the amount of energy feedback to said laser rod; and d. logic circuitry connected to said deflector for selectively applying said ultrasonic power at selected power levels to control the fraction of said beam deflected, thereby controlling the energy level of respective pulses and the time interval therebetween.

Claim 6

A laser system as set forth in in claim 3 including third reflective means disposed along a line joining said second reflective means and said deflector, said third reflective means being positioned such that said deflector lies between said second and third reflective means.

Claim 7

A laser system as set forth in claim 4 and further including a fourth reflective means disposed along said longitudinal axis, said fourth reflecting means being positioned on the same side of said deflector as said second reflective means and being operable to provide a selected amount of feedback to said laser rod.

Claim 8

A laser system for selectively producing variable energy pulses at variable time intervals comprising: a. a laser cavity including a laser rod intermediate first and second reflecting means, said first reflective means being disposed along and substantially perpendicular to the longitudinal axis of said laser rod and said second reflecting means being displaced from said longitudinal axis; b. an acousto-optic beam deflector for selectively controlling the lasing threshold of said laser cavity, said deflector disposed within said cavity along said longitudinal axis intermediate said laser rod and said second reflecting means, said second reflecting means being substantially perpendicular to a line joining said second reflecting means and said deflector, said deflector effective to deflect a fraction of an energy beam from said rod at a preselected angle responsive to application of ultrasonic power thereto, said fraction being a monotonic increasing function of said power, said deflected fraction defining the amount of energy feedback to said laser rod; c. a source of RF power; d. logic control means for selectively applying said RF power to said acousto-optic beam deflector in amounts and at intervals corresponding to desired laser pulses, said applied RF power being effective to deflect a variable portion of the radiation emitted by said laser rod at said preselected angle to said second reflecting means therby selectively varying the lasing threshold of said cavity; and e. means for increasing the population inversion in said laser rod to stimulate emission of radiation therefrom.

Claim 9

A laser system for selectively producing variable energy pulses at variable time intervals comprising: a. a laser cavity including a laser rod intermediate first and second reflecting means, said first reflective means being disposed along and substantially perpendicular to the longitudinal axis of said laser rod and said second reflecting means being displaced from said longitudinal axis; b. an acousto-optic beam deflector for selectively controlling the lasing threshold of said laser cavity, said deflector disposed within said cavity along said longitudinal axis intermediate said laser rod and said second reflecting means, said second reflecting means being substantially perpendicular to a line joining said second reflecting means and said deflector, said deflector effective to deflect a fraction of an energy beam from said rod at a preselected angle responsive to application of ultrasonic power thereto, said fraction being a monotonic increasing function of said power, said deflected fraction defining the amount of energy feedback to said laser rod; c. a source of RF power; d. logic control means for selectively applying said RF power to said acousto-optic beam deflector in amounts and at intervals corresponding to desired laser pulses, said applied RF power being effective to deflect a variable portion of the radiation emitted by said laser rod at said preselected angle to said second reflecting means therby selectively varying the lasing threshold of said cavity; and e. means for increasing the population inversion in said laser rod to stimulate emission of radiation therefrom.

Claim 10

A laser system as set forth in claim 6 further including third reflective means disposed along the line joining said second reflective means and said deflector, said third reflective means being positioned such that said deflector lies between said second and third reflecting means.

Claim 11

A laser system as set forth in claim 7 further including a fourth reflecting means disposed along said longitudinal axis, said fourth reflecting means being positioned on the same side of said deflector as said second reflecting means and being operable to provide a selected amount of feedback to said laser rod.

Claim 12

A laser system for selectively producing variable energy laser pulsEs at variable time intervals comprising: a. a laser cavity including a laser rod intermediate first and second reflecting means disposed along and substantially perpendicular to the longitudinal axis of said laser rod, and output means displaced from said longitudinal axis; b. an acousto-optic beam deflector disposed within said cavity along said longitudinal axis between said laser rod and both said output means and said second reflecting means; c. a source of RF power; d. logic control means for selectively applying said RF power to said acousto-optic beam deflector at power levels and at intervals corresponding with desired laser pulses, said applied RF power deflecting radiation emitted by said laser rod away from said second reflective means to decrease feedback; and e. means for increasing the population inversion in said laser rod whereby said applied RF power selectivity varies the amount of radiation reflected back to said laser rod and thus selectively controls the gain of said laser cavity.

Claim 13

A laser system for selectively producing variable energy laser pulsEs at variable time intervals comprising: a. a laser cavity including a laser rod intermediate first and second reflecting means disposed along and substantially perpendicular to the longitudinal axis of said laser rod, and output means displaced from said longitudinal axis; b. an acousto-optic beam deflector disposed within said cavity along said longitudinal axis between said laser rod and both said output means and said second reflecting means; c. a source of RF power; d. logic control means for selectively applying said RF power to said acousto-optic beam deflector at power levels and at intervals corresponding with desired laser pulses, said applied RF power deflecting radiation emitted by said laser rod away from said second reflective means to decrease feedback; and e. means for increasing the population inversion in said laser rod whereby said applied RF power selectivity varies the amount of radiation reflected back to said laser rod and thus selectively controls the gain of said laser cavity.

Claim 14

A laser system as set forth in claim 9 further including third reflective means disposed along a line joining said output means and said deflector, said third reflective means being positioned such that said deflector lies between said third reflective means and said output means.

Claim 15

A laser system as set forth in claim 10 further including a fourth reflective means disposed along said longitudinal axis, said fourth reflective means being positioned on the same side of said deflector as said second reflecting means and being operable to provide a selected amount of feedback to said laser rod.

Claim 16

A laser system for selectively producing variable energy laser pulses at variable time intervals comprising: a. a laser rod; b. first reflecting means positioned from one end of said laser rod along said substantially perpendicular to the longitudinal axis of said laser rod; c. output means positioned from the opposite end of said laser rod along said longitudinal axis; d. a beam splitter positioned along said longitudinal axis between said laser rod and said output means; e. second reflective means positioned along a line substantially perpendicular to said longitudinal axis, said second reflective means being positioned on the side of said longitudinal axis opposite and in alignment with the direction said beam splitter reflects the beam radiated by said laser rod; f. acousto-optic beam deflector means positioned along a line substantially perpendicular to said longitudinal axis on the opposite side thereof from said second reflective means and in alignment with the portion of said beam reflected from said beam splitter; g. control means connected to said deflector for varying the amount of acoustic power applied thereto; h. means for increasing the population inversion in said laser rod; and i. feedback reflecting means disposed along a line that forms an angle with said beam reflected by said beam splitter whereby in response to applied power to said deflector a fraction of the beam from said laser rod reflected by said beam splitter is deflected to impinge upon said feedback reflecting means to be reflected therefrom to provide energy feedback to said laser rod, the portion of said feedback energy that is transmitted through said beam splitter being reflected by said second reflecting means back to said beam splitter.

Claim 17

A laser system for selectively producing variable energy laser pulses at variable time intervals comprising: a. a laser rod; b. first reflecting means positioned from one end of said laser rod along said substantially perpendicular to the longitudinal axis of said laser rod; c. output means positioned from the opposite end of said laser rod along said longitudinal axis; d. a beam splitter positioned along said longitudinal axis between said laser rod and said output means; e. second reflective means positioned along a line substantially perpendicular to said longitudinal axis, said second reflective means being positioned on the side of said longitudinal axis opposite and in alignment with the direction said beam splitter reflects the beam radiated by said laser rod; f. acousto-optic beam deflector means positioned along a line substantially perpendicular to said longitudinal axis on the opposite side thereof from said second reflective means and in alignment with the portion of said beam reflected from said beam splitter; g. control means connected to said deflector for varying the amount of acoustic power applied thereto; h. means for increasing the population inversion in said laser rod; and i. feedback reflecting means disposed along a line that forms an angle with said beam reflected by said beam splitter whereby in response to applied power to said deflector a fraction of the beam from said laser rod reflected by said beam splitter is deflected to impinge upon said feedback reflecting means to be reflected therefrom to provide energy feedback to said laser rod, the portion of said feedback energy that is transmitted through said beam splitter being reflected by said second reflecting means back to said beam splitter.

Claim 18

A laser system as set forth in claim 12 wherein said feedback reflecting means are disposed along a line substantially perpendicular to said longitudinal axis and in alignment with the portion of said beam reflected by said beam splitter.

Claim 19

A laser system as set forth in claim 12 including third reflective means disposed along a line joining said feedback reflective means and said deflector, said third reflective means being positioned such that said deflector lies between said third reflective means and said feedback reflective means.