System and method for amplifying an optical pulse and pumping laser therefor

Abstract

An efficient, powerful and reliable system for amplifying optical pulses. Seed-pulses are generated by a seed-pulse source and are transmitted to an optical amplifier for amplification. The power for the amplification is provided by a Q-switched, diode-pumped, intracavity-doubled pump laser.

1. A method for amplifying an optical pulse in a laser comprising the steps of:
 generating a pulsed light in a Q-switched, amplifier pump laser including an intracavity frequency altering device wherein said pump laser includes an elongated gain medium have a light propagation axis extending longitudinally therethrough and wherein said gain medium is pumped by at least two elongated diode laser pump sources mounted along the side of the gain medium at two circumferentially spaced apart positions; 
 directing the pulsed light to an optical gain element of an optical amplifier comprising a medium of optically responsive atoms; 
 exciting the atoms to a metastable state using the pulsed light; and 
 directing a seed pulse at the gain element of an said optical amplifier, thereby causing the excited atoms to emit an amplified optical pulse.; and 
 redirecting the amplified optical pulse through the gain element, thereby causing the excited atoms to emit a further amplified optical pulse. 
 
     
     
       2. The method of  claim 1  wherein said step of generating a pulsed light includes altering a frequency of said light with a frequency altering device. 
     
     
       3. The method of claim  2  1 wherein said step of altering the frequency of said light utilizes intracavity frequency altering device is a frequency doubling crystal. 
     
     
       4. The method of  claim 2  further comprising:
 disposing intracavity said frequency altering device. 
 
     
     
       5. The method of claim  2  1 wherein said step of generating a pulsed light includes providing output coupler means. 
     
     
       6. A method for generating and amplifying an optical pulse comprising the steps of:
 exciting atoms in a laser medium said laser medium being elongated and having a light propagation axis extending longitudinally therethrough and wherein said laser medium is pumped by at least two elongated diode laser pump sources mounted along the side of the gain medium at two circumferentially spaced apart positions; 
 causing oscillation in said laser medium using a Q-switch disposed along an optical path to produce laser light along said optical path; 
 altering the frequency of at least some of said laser light along said optical path using an intracavity frequency altering device; 
 selectively releasing laser light having the altered frequency from said optical path; 
 receiving the selectively released laser light at an a regenerative optical amplifier to provide optical energy to the optical amplifier; and 
 receiving a seed-pulse at the regenerative optical amplifier to cause the optical amplifier to emit an amplified optical pulse. 
 
     
     
       7. The method of  claim 6  wherein said step of altering the frequency is performed by a an intracavity frequency doubling crystal. 
     
     
       8. The method of  claim 7  wherein said frequency doubling crystal is intracavity disposed. 
     
     
       9. The method of  claim 6  wherein said step of selectively releasing laser light is performed by an optical coupler. 
     
     
       10. The method of  claim 6  wherein the steps of receiving the selectively released laser light and receiving a seed-pulse are performed by a gain medium element. 
     
     
       11. A system for amplifying optical pulses comprising:
 a seed-pulse source for producing optical seed-pulses; 
 an optical amplifier disposed to receive said seed-pulses from said seed-pulse source, for receiving and amplifying said seed-pulses and for outputting amplified seed-pulses; and 
 an amplifier pumping laser for providing optical energy to said optical amplifier for the amplification of said seed-pulses, said amplifier pumping laser including an elongated gain medium have a light propagation axis extending longitudinally therethrough and wherein said gain medium is pumped by at least two elongated diode laser pump sources mounted along the side of the gain medium at two circumferentially spaced apart positions, an intracavity frequency altering device, and a switching means for selectively frustrating or allowing optical resonance, thereby enabling said amplifier pumping laser to emit pulses of laser light; and 
 a plurality of beam directors positioned to redirect each seed-pulse through a gain medium of the optical amplifier, whereby each seed-pulse makes more than one pass through the gain medium. 
 
     
     
       12. The system of  claim 11  wherein said switching means comprises a Q-switch. 
     
     
       13. The system of  claim 11  wherein said frequency altering device comprises a frequency doubling crystal. 
     
     
       14. A system for amplifying optical pulses, comprising:
 aan elongated lasing material having a light propagation axis extending longitudinally therethrough and wherein said gain medium is pumped by at least two elongated diode laser pump sources mounted along the side of the gain medium at two circumferentially spaced apart positions; 
 switching means for selectively frustrating or allowing optical resonance in said lasing material; 
 aan intracavity frequency altering device for altering the frequency of light emitted from said lasing material; 
 a seed pulse source for producing optical seed-pulses; and 
 ana regenerative optical amplifier disposed to receive the optical seed-pulses from the seed pulse source and to receive light emitted from the frequency altering device to amplify the optical seed-pulses with optical energy from the light emitted from the frequency altering device. 
 
     
     
       15. The pumping laser system of  claim 14  wherein said switching means comprises a Q-switch. 
     
     
       16. The pumping laser system of  claim 14  wherein said frequency altering device comprises a frequency doubling crystal. 
     
     
       17. A system for amplifying optical pulses, comprising:
 a seed pulse source for producing optical seed-pulses; 
 ana regenerative optical amplifier disposed to receive the seed-pulses from the seed-pulse source, for receiving and amplifying the seed pulses and for outputting amplified seed-pulses; and 
 an amplifier pumping laser for providing optical energy to the optical amplifier for the amplification of the seed-pulses, the amplifier pumping laser including a an elongated gain medium have a light propagation axis extending longitudinally therethrough and wherein said gain medium is pumped by at least two elongated diode laser pump sources mounted along the side of the gain medium at two circumferentially spaced apart positions, an intracavity frequency altering device and a switching device for selectively frustrating or allowing optical resonance, thereby enabling the amplifier pumping laser to emit pulses of laser light. 
 
     
     
       18. A system for amplifying optical pulses, comprising:
 a seed pulse source for producing optical seed-pulses;   an optical amplifier disposed to receive the seed-pulses from the seed-pulse source, for receiving and amplifying the seed pulses and for outputting amplified seed-pulses; and   an amplifier pumping laser for providing optical energy to the optical amplifier for the amplification of the seed-pulses, the amplifier pumping laser including an intracavity frequency altering device and a switching device for selectively frustrating or allowing optical resonance, thereby enabling the amplifier pumping laser to emit pulses of laser light.   
     
     
       19. A system for amplifying optical pulses, comprising:
 an amplifier pumping laser for providing optical energy to an a regenerative optical amplifier for the amplification of seed-pulses; 
 the amplifier pumping laser including an elongated gain medium have a light propagation axis extending longitudinally therethrough and wherein said gain medium is pumped by at least two elongated diode laser pump sources mounted along the side of the gain medium at two circumferentially spaced apart positions and configured to produce light, an intracavity frequency altering device configured to alter a frequency of the produced light, and a switching device for selectively frustrating or allowing optical resonance, thereby enabling the amplifier pumping laser to emit pulses of laser light. 
 
     
     
       20. The method of claim 1, further comprising:
 altering a polarization of the seed-pulse, the polarization determining whether the seed-pulse is redirected through the gain element or directed as an output pulse.   
     
     
       21. The system of claim 11, wherein:
 the plurality of beam directors directs the seed-pulse along separate paths through the gain element.   
     
     
       22. The system of claim 11, wherein:
 the plurality of beam directors form a ring path around the gain element.   
     
     
       23. The system of claim 11, further comprising:
 a polarizing element for altering a polarization of the seed-pulse.   
     
     
       24. The system of claim 23, further comprising:
 a beam splitting element for directing the seed-pulse as an output pulse when the seed-pulse has a predetermined polarization.   
     
     
       25. A method for amplifying an optical pulse in a laser comprising the steps of:
 generating a pulsed light in a Q-switched, diode-pumped, amplifier pump laser including an intracavity frequency altering device, the amplifier pump laser including a gain medium having a highly reflective material disposed about a radial outer surface thereof, the highly reflective material having at least one opening for admitting radiation from a diode laser for exciting atoms of the gain medium;   directing the pulsed light to an optical gain element comprising a medium of optically responsive atoms;   exciting the atoms to a metastable state using the pulsed light; and   directing a seed pulse at the gain element of an optical amplifier, thereby causing the excited atoms to emit an amplified optical pulse.   
     
     
       26. The method of claim 25 wherein the amplifier pumping laser further includes a plurality of diode lasers. 
     
     
       27. The method of claim 26 wherein the plurality of diode lasers are disposed along a lateral surface of the gain medium. 
     
     
       28. The method of claim 25 wherein radiation generated by the diode laser passes more than once through the gain medium. 
     
     
       29. A system for amplifying optical pulses comprising:
 a seed-pulse source for producing optical seed-pulses;   an optical amplifier disposed to receive said seed-pulses from said seed-pulse source, for receiving and amplifying said seed-pulses and for outputting amplified seed-pulses; and   an amplifier pumping laser for providing optical energy to said optical amplifier for the amplification of said seed-pulses, said amplifier pumping laser including a gain medium having a highly reflective material disposed about a radial outer surface thereof, a diode laser positioned to direct radiation through an opening in the highly reflective material in order to excite atoms of the gain medium, an intracavity frequency altering device, and a switching means for selectively frustrating or allowing optical resonance, thereby enabling said amplifier pumping laser to emit pulses of laser light.   
     
     
       30. The system of claim 29, wherein:
 the amplifier pumping laser further includes a plurality of diode lasers.   
     
     
       31. The system of claim 30, wherein:
 the plurality of diode lasers are disposed along a lateral surface of the gain medium.   
     
     
       32. The system of claim 29, wherein:
 radiation generated by the diode laser passes more than once through the gain medium.