We report 1.3 µm InGaAlAs/InP lasers integrated with laterally tapered spot size converter (SSC) in reverse mesa shape. Because the top width is significantly larger than the bottom width for the reverse mesa ridge, high quality SSCs having narrow tip width can be fabricated through conventional photolithography with a high reproductivity. The Threshold current of the fabricated 1000 µm long SSC integrated device is 25 mA and 44 mW single facet optical power can be obtained at 300 mA current. The lateral and vertical divergence angles are as low as 8 ° and 11°, respectively.