The ASE-Free version of our standard double-clad erbium/ytterbium co-doped polarization-maintaining fiber is specifically engineered to minimize ASE around 1µm, effectively supressing parasitic ytterbium emission and enabling higher output power with stable amplification. Its optimized glass composition and efficient energy transfer maximize pump utilization while reducing pump power requirements. Combined with a polarization-maintaining design, this fiber delivers higfh efficiency, excellent beam quality, and outstanding power scalability for eye-safe, high-power fiber laser and amplifier applications.