title: 50 W low noise dual-frequency laser fiber power amplifier.
abstract: A three-stage dual-frequency laser signal amplification system is presented. An output from a narrow-linewidth Nd:YAG nonplanar ring-oscillator (NPRO) is split into two parts, one of them is frequency shifted by an acoustooptic modulator (AOM) then coupled into a single mode optical fiber. The other part is coupled into another single mode fiber then combined with the frequency-shifted beam with a 2 to 1 single mode fiber coupler. The combined beam has a power of 20 mW containing two frequency components with frequency separation of 150 ± 25 MHz. The dual-frequency signal is amplified via a three-stage Yb3+-doped diode pumped fiber power amplifier. The maximum amplified power is 50.3 W corresponding to a slope efficiency of 73.72% of the last stage. The modulation depth and signal to noise ratio (SNR) of the beat signal are well maintained in the amplifying process. The dual-frequency laser fiber power amplifier provides robust optical carried RF signal with high power and low noise.
authors.forename: Ying
authors.initials: Y
authors.lastname: Kang
authors.forename: Lijun
authors.initials: L
authors.lastname: Cheng
authors.forename: Suhui
authors.initials: S
authors.lastname: Yang
authors.forename: Changming
authors.initials: C
authors.lastname: Zhao
authors.forename: Haiyang
authors.initials: H
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: He