Apparatus and method for optical energy amplification using two-beam coupling

An optical energy transfer system, comprising:

• first and second sources of coherent first and coherent pump optical beams at different respective wavelengths and frequencies,
• means for diverting a portion of said first beam into a probe beam having the same frequency as first beam,
• means for modulating the frequency of said probe beam,
• means for transferring energy from said pump beam to said first beam after diversion of said probe beam, thereby amplifying said first beam,
• a rare earth doped resonant transfer host medium that provides a resonant energy transfer medium between, and is located in the paths of, said amplified first beam and said modulated probe beam, and
• means for coupling said frequency modulated probe beam and amplified first beam within said resonant transfer host medium so that they beat against each other and generate interference gratings as a result of frequency differences between the frequency modulated probe and amplified first beams, said gratings producing a coherent scattering of the amplified first beam that effects a resonant energy transfer from said amplified first beam to said probe beam.

A diffraction limited method of transferring energy from a coherent optical pump beam at one wavelength to a first optical beam at another wavelength, comprising:

• generating said first beam as a substantially diffraction limited coherent beam,
• diverting a portion of said first beam as a substantially diffraction limited coherent probe beam,
• transferring energy from said pump beam to said first beam after diversion of said probe beam to yield a substantially non-diffraction limited amplified first beam, and
• transferring energy from said amplified first beam to said probe beam in a substantially diffraction-limited energy transfer process to yield a substantially diffraction limited amplified probe beam at said first beam wavelength.