A semiconductor gain element has an active waveguide incident at an angle greater than normal incidence on an end facet. The waveguide may be a single stripe or may be a stripe coupled to a flared region. The waveguide may include a curved portion to produce the non-normal incidence on the end facet....http://www.google.de/patents/US6118802?utm_source=gb-gplus-sharePatent US6118802 - Optically amplifying semiconductor diodes with curved waveguides for external cavities
