Optically amplifying semiconductor diodes with curved waveguides for external cavities

摘要

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. The gain element may be used as the gain element within a tunable, external cavity laser, or may also be used as an amplifier to amplify an external signal. The waveguide may be formed from a central portion surrounded laterally by cladding regions. Further, absorbing regions may be positioned outside the cladding regions to absorb light that does not propagate within the waveguide.