Abstract

A model for a coherent array of amplifiers that has multiple stages and uses pairwise beam combining at the final stage has been developed. The model accounts for gain saturation of the individual amplifier elements, optical-coupling losses, and coherent-combining efficiency. The individual amplifier parameters are derived from experimental data. System size, efficiency, and output power are calculated as functions of optical-coupling efficiency and combining efficiency. Because of the exponential losses associated with pairwise beam combining, the coherent-combining losses are the dominant contribution to system efficiency reduction and increased system size.

© 1995 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. M. D. Williams, E. J. Conway, eds., Space Laser Power Transmission System Studies, NASA Conf. Publ. 2214 (NASA, Washington, D.C., 1982).
  2. R. J. Deyoung, ed., Second Beamed Space-Power Workshop, NASA Conf. Publ. 3037 (NASA, Washington, D.C., 1989).
  3. G. L. Schuster, J. R. Andrews, “Coherent summation of saturated AlGaAs amplifiers,” Opt. Lett. 18, 619–621 (1993), and references therein.
    [CrossRef] [PubMed]
  4. A. E. Siegman, Lasers (University Science, Mill Valley, Calif., 1986), p. 324.
  5. J. Andrews, “Interferometric power amplifiers,” Opt. Lett. 14, 33–35 (1989).
    [CrossRef] [PubMed]

1993

1989

Opt. Lett.

Other

M. D. Williams, E. J. Conway, eds., Space Laser Power Transmission System Studies, NASA Conf. Publ. 2214 (NASA, Washington, D.C., 1982).

R. J. Deyoung, ed., Second Beamed Space-Power Workshop, NASA Conf. Publ. 3037 (NASA, Washington, D.C., 1989).

A. E. Siegman, Lasers (University Science, Mill Valley, Calif., 1986), p. 324.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (4)

Fig. 1
Fig. 1

Schematic of cascade amplifier system with a branching ratio of 4 throughout the system when pairwise collinear beam combining is used.

Fig. 2
Fig. 2

Coupling-efficiency effects on system efficiency and combined coherent power. The gain is adjusted for each coupling efficiency so that maximum system efficiency is achieved, and the component-combining efficiency is held at unity (ηcomb = 1).

Fig. 3
Fig. 3

Combining-efficiency effects on system efficiency and power. The gain is varied from 6 to 12 dB, and the coupling efficiency is held at unity (ηcpl = 1). The structure shown at the higher combining efficiencies is a series of overlapping peaks, with each peak corresponding to a different number of stages in the system.

Fig. 4
Fig. 4

Effects of interstage optical-coupling efficiency and coherent-combining efficiency on system size and power.

Equations (6)

Equations on this page are rendered with MathJax. Learn more.

P j out = Γ γ 0 - α 0 α 0 P sat [ 1 - ( G 0 G j ) α 0 / Γ γ 0 ] [ 1 G j - ( G 0 G j ) α 0 / Γ γ 0 ] ,
P j out = G j ( N j - 1 N j η cpl P j - 1 out ) ,
P j out = ( m = 1 j η cpl G m ) N j P 0 ,
N j = ( m = 1 j η cpl G m ) P 0 α 0 [ 1 G j - ( G 0 G j ) α 0 / Γ γ 0 ] ( Γ γ 0 - α 0 ) P sat [ 1 - ( G 0 G j ) α 0 / Γ γ 0 ] .
η cascade = ( η comb ) log ( N j ) / log ( 2 ) ,
P comb = ( m = 1 j η cpl G m ) P 0 ( η comb ) log ( N j ) / log ( 2 ) .

Metrics