This paper reports the fabrication of J-shaped bent-waveguide superluminescent diodes utilizing an InAl- GaAs/AlGaAs quantum dot active region. The emission spectrum of the device is centred at 884 nm with a full width at half maximum of 37 nm and an output power of 18 mW. By incorporating an Al composition into the quantum dot active region, short-wavelength superluminescent diode devices can be obtained. An intersection was found for the light power-injection current curves measured from the straight-waveguide facet and the bent-waveguide facet, respectively. The result is attributed to the conjunct effects of the gain and the additional loss of the bent waveguide. A numerical simulation is performed to verify the qualitative explanation. It is shown that bent waveguide loss is an important factor that affects the output power of J-shaped superluminescent diode devices. This paper reports the fabrication of J-shaped bent-waveguide superluminescent diodes utilizing an InAl- GaAs / AlGaAs quantum dot active region. The emission spectrum of the device is centred at 884 nm with a full width at half maximum of 37 nm and an output By incorporating an Al composition into the quantum dot active region, short-wavelength superluminescent diode devices can be obtained. An intersection was found for the light power-injection current curves measured from the straight-waveguide facet and the bent- The result is attributed to the conjunct effects of the gain and the additional loss of the bent waveguide. It is shown that bent waveguide loss is an important factor that affects the output power of J-shaped superluminescent diode devices.