中文摘要：

对功率比可调谐的双波长光纤激光器及其保偏光纤功率放大器特性进行研究。以中心波长分别为1030nm和1035nm的两对光纤光栅作为谐振腔镜，通过引入1035nm波长激光可调节的腔内损耗，实现了功率比可调的双波长光纤激光器。以双波长光纤激光器为种子光源，建立了二级保偏光纤功率放大系统，通过控制双波长信号的功率比，研究了种子光特性对双波长功率放大的影响，获得了功率比可调的1035nm和1030nm双波长激光的放大输出，在双波长等幅输出情况下，最高功率达7．77W。通过增大抽运功率或增加放大级数，可以获得更高功率的可调双波长激光输出，为今后应用于非线性光学差频产生太赫兹波提供了可能。

英文摘要：

The power-ratio-tunable dual-wavelength fiber laser with linearly-polarized output and its polarization maintaining fiber power amplifier are demonstrated. Two pairs of fiber Bragg gratings with polarization-matching techniques are employed as the mirrors of the resonator to insure the linearly-polarized output with central wavelengths of 1035 nm and 1030 nm, respectively. By introducing the cavity loss at 1035 nm, the power ratio of the two wavelengths can be continuously changed. With the dual-wavelength fiber laser as the seed, two-stage polarization maintaining fiber amplifier is established to scale up the output power. By changing the power-ratio of the two wavelengths of the seed, the affection of seed characteristics on the dual-wavelength power amplification is studied to realize the adjustable power-ratio of the amplified output. When the output amplitude of dual-wavelength on the spectrum is tuned to be equal, the maximum output power of 7.77 W is achieved. Future power scaling operation can be achieved by increasing the pump power or adding the amplification stages, which provides the possibility in application to generate terahertz wave by optical nonlinear difference frequency.