A violet InGaN multi-quantum well/GaN/AlGaN separate- confinement-heterostructure laser diode (LD) was grown on epitaxially laterally overgrown GaN on sapphire. The threshold current density was 2 - 4 kA/cm2. The LDs with cleaved mirror facets showed an output power as high as 30 mW under room-temperature continuous-wave (CW) operation. The stable fundamental transverse mode in the near-field patterns was observed at an output power up to 30 mW. The lifetime of the LDs at a constant output power of 5 mW was more than 1,900 hours under CW operation at an ambient temperature of 50 degree(s)C.