Abstract

A diffraction limited working beam at a given frequency is amplified without degrading its diffraction limited quality by diverting a minor portion of the beam as a probe beam, and amplifying the remaining portion of the working beam with a high power pump beam at a different wavelength. The amplification takes place in a host medium that has a rare earth dopant with an energy transition from the pump beam's wavelength to the wavelength of the working beam. The resulting amplified working beam is non-diffraction limited. The probe beam is frequency modulated and coupled with the amplified working beam in a second host medium that also has a rare earth dopant. Energy is transferred from the amplified working beam to the modulated probe beam through a resonant energy transfer in the second host medium, producing an amplified output beam at the working beam frequency that retains the diffraction limited quality of the probe beam.

Other References

• "Phase conjugate master oscillator-power amplifier using BaTiO₃ and AlGaAs semiconductor diode lasers", Applied Phys. Ltrs., vol. 50, pp. 647-649 (1987), Stephens et al
• "Coherent addition of AlGaAs lasers using microlasers and diffractive coupling", Applied Phys. Ltrs., vol. 52, pp. 1771-1773, (1988), Ledger et al
• "Coherent coupling of independent grading-surface-emitting diode laser array using an external prism", Appl. Phys. Ltrs., vol. 56, pp. 114-116 (1990), Carlson et al
• "Fabrication of a two-dimensional phased array of vertical-cavity surface-emitting lasers", Appl. Phys. Ltrs., vol. 56, p. 1198, (1990), Yoo et al
• "FM response of narrow-linewidth multielectrode λ/4 shift DFB laser", Photonics Technology Ltrs., vol. 2, p. 165, (1990), Ogita et al
• Berman et al., Spectral Line Shapes, vol. 3, F. Rostos et al., published by DeGruyter of Berlin, pp. 337-339 (1985)
• "Low noise erbium-doped fiber amplifier operating at 1.54 μm", Electronics Ltrs., vol. 23, pp. 1026-1028, (1987), Mears et al
• "Gain Saturation Effects in High-Speed, Multichannel Erbium-Doped Fiber Amplifiers at λ=1.53 μm", Journal of Lightwave Technology, vol. 7, No. 12, Dec. 1989, pp. 2045-2104, Desurvire et al
• "Erbium Doped Fibers for Efficient Optical Amplifiers", IEEE Proceedings, vol. 137, Pt. J., No. 4, Aug. 1990, pp. 205208, Ainslie et al
• "Erbium-Doped Fiber Amplifier with Flattened Gain Spectrum", IEEE Photonics Ltrs., vol. 3, No. 2, Feb. 1991, pp. 118-120, Tachibana et al
• "A 970 nm strained-layer SnGaAs/GaAlAs quantum well laser for pumping an erbium-doped optical fiber amplifier", Appl. Phys. Ltrs., vol. 56, pp. 221-223 (1990), Wu et al
• "Strained-layer ZnGaAs/AsAs/AlGaAs single quantum well lasers with high internal quantum efficiency", Appl. Phys. Ltrs., vol. 55, pp. 22682270, (1989), Larson et al
• "980 nm diode laser for pumping Er³⁺ .div.doped fiber amplifiers", Photonics Technology Ltrs., vol. 2, pp. 153-155 (1990), Bour et al
• "Diffraction-limited operation from monolithically integrated diode laser array and self-imaging (Talbot) cavity", Appl. Phys. Ltrs., 55(19), Nov. 6, 1989, pp. 1949-1951, M. Jansen et al
• "Binary-optics miniature Talbot cavities for laser beam addition", Appl. Phys. Ltrs., 56(1), Jan. 1, 1990, p. 46, J. R. Leger et al
• Applied Physics Letters, vol. 34, No. 7, Apr. 1, 1979, New York, pp. 463-464, A. Tomita, "Phase Conjugation Using Gain Saturation of a Nd:YAG Laser"
• Physical Review, B. Condensed Matter, vol. 45, No. 13, Apr. 1, 1992, New York, pp. 7077-7083, M. Broer et al., "Photoinduced refractive-index changes in several Eu³⁺ -, Pr³⁺ -, and Er³⁺ -doped oxides glasses