We demonstrate a monolithic continuous wave (CW) fiber laser oscillato r,producing ～1.63kW laser power at 1080nm.In our experiment,the monolithic la ser oscillator was pumped by 7fiber-pigtailed laser diodes with the maximum output power of ~300W.The operating wavelengths of all these pump laser diodes are near 976nm,enabling a short laser cavity (~27m) to effec tively suppress the stimulated Raman scattering (SRS).The laser spectrum with the maximum output power has a si gnal to noise ratio (SNR) more than 40dB.In addition,the fiber coiling technique was adopted to eff ectively depre ss the high-order laser modes to obtain the single mode beam quality (M²<1.1) at the ma ximum output laser power.The optical to optical conversion efficiency of the monolithic laser oscillator with respect to the lau nched pump power is as high as ~75.46%.The laser oscillator kept running for an hour at the maximum output pow er.No power roll-over was observed and power fluctuation lower than 1% was achieved.The all fiber construc tion of the laser oscillator enables compact size,maintenance-free,robust operation and thus allows various practi cal applications in industry material processing,such as laser cutting,laser drilling,laser clamping,lase r welding,etc.