Novel design for high power single lateral mode lasers

Summary form only given. Today's rising power requirement for semiconductor lasers has created much interest in the research of high power single lateral mode lasers. Single lateral mode lasers are generally narrow in width in order to cut off propagation of higher order modes. Several problems arise from the narrow geometry such as catastrophic optical mirror damage (COMD), a large diffraction angle, and limited power due to the small gain volume. Recently, flared waveguides have been studied for increased gain volume and increased spot size on the front facet. The larger gain volume increases the peak output power of the diode. The increased spot size will raise the COMD power level by lowering the power density at the facet. The increased spot size will also decrease the diffraction angle. A problem with flaring the waveguide is that as the waveguide increases in width, it can support propagation of higher order modes. Our design addresses this by utilizing selective area epitaxy (SAE) to create a ridge that gets thinner as its width increases. The result is a flared ridge that is tapered along the length of the laser.