Superluminescent diodes with angled facet etched by chemically assisted ion beam etching

A superluminescent diode with very low spectral modulation has been made with one cleaved facet and one angled facet etched by chemically assisted ion beam etching. Without antireflection coating, the reflection of light back into the waveguide from the etched angled facet is less than 1*10^-5. In addition, 85% of the total output power can be coupled from the etched angled facet without applying any antireflection or high-reflection coating on either facet.