By introducing wavelength tunability, InGaN single longitudinal mode lasers can be used for pumping wavelength conversion devices with a small pump wavelength tolerance. A 405 nm InGaN tunable slotted laser was designed and fabricated by a simple process without high-resolution lithography and epitaxial regrowth. Continuous-wave single-mode oscillation was obtained. By current injection to active and slotted channels separately, a wavelength tuning range of 0.55 nm was successfully demonstrated for the first time in InGaN in-plane single-mode lasers.