To improve the output power of InGaN superluminescent diodes (SLED), an active multimode-interferometer (Active-MMI) configuration has been used to fabricate the Active-MMI SLED. Because of the wider actively pumped area, the output power saturation level has been improved. The experiment results show that the maximum output power of Active-MMI SLED as high as 47 mW is obtained with a wide 3 dB bandwidth of 20 nm and flat spectrum. Moreover, even under the maximum output power of Active-MMI SLED, it still keeps a stable single mode output.