The red semiconductor laser diodes are widely used in landscape lighting.plasti c optical fiber communication,air quality testing and medical treatment.However, th eir low reliability and poor spot quality increase the cost in the production of point sources or coupling into optical fibers.To solve this problem, a 650nm ridge laser diode is designed and fabricated to maintai n a fundamental transverse mode operation.Considering the characteristics of AlG aInP material,we used a very narrow waveguide to expand the optical field into t he cladding layers.By increasing the optical field expansion width,the vertical divergence angle could be effectively reduced.The 2μm-wide steep ridge structure is obtained by inductively coupled plasma etching.Then the wet etching process was employed to remove the damage layer and stopped at the etching stop layer.The combination of dry and wet process stabilized the fundame ntal transverse mode.The far-field pattern of the laser is nearly circular,whic h overcomes the shortcoming of traditional semiconductor lasers with long and na rrow spots.The power curve shows no kink at power test even above 30mW.The lase r has passed the aging test of 10mW at 60℃,and the estimated m ean time to failure (MTTF) is more than 18000h.