United States of America As Represented by the Secretary of the Air Force

Clint M Zeringue

Iyad A Dajani

Thomas M Shay

Timothy J Bronder

A method to increase the output power of monolithic narrow-linewidth Yb-doped fiber amplifiers by suppressing simulated Brillouin scattering. The fiber amplifier employs a co-propagating geometry and is seeded with broad- (source) and narrow- (source) linewidth signals that are sufficiently different in wavelengths to allow for efficient gain competition and favorable temperature profile at the output end of fiber. The broadband seed signal possesses the higher emission and absorption cross sections. If sourceis also given sufficiently greater input power than source, it will be amplified to its maximum value as the seed signals reach the middle portion of the gain fiber. Beyond that portion, the signal having the lower emission and absorption cross sections (signal) will continue to experience gain by power transfer from both signaland the pump light, attaining a power output well beyond what the maximum output would have been had the amplifier been illuminated with a single frequency beam. Furthermore, if the two signals are carefully selected such that appreciable quantum defect heating occurs during the power transfer, a steep thermal gradient develops leading to even further increase in output power.

Scalable monolithic single frequency fiber amplifier

A method to increase the output power of narrow-linewidth rare earth-doped fiber amplifiers by suppressing simulated Brillouin scattering. The fiber amplifier is seeded with two or more lasers having frequencies and input powers that are sufficiently different. The seed signal with the highest emission cross section (e.g., signal) initially experiences the greatest gain. If signalis also given sufficiently greater input power than signalit will be amplified to its maximum value before the seed signals have reached the midpoint of the gain fiber. Beyond that point, the signal having the lower emission and absorption cross sections (signal) and significantly lower input power will continue to experience gain by power transfer from both signaland the pump light, attaining a power output well beyond what the maximum output would have been had the amplifier been illuminated with a single frequency beam. This technique effectively reduces the Stokes light of signalwhereby higher power narrow-linewidth optical fiber amplifiers may be realized.

Growing community of inventors

Albuquerque, NM, United States of America

Clint M Zeringue