Effects of rapid thermal annealing on the optical properties of low-loss 1.3 μ m GaInNAs ∕ GaAs saturable Bragg reflectorsInfluence of rapid thermal annealing on a 30 stack InAs/GaAs quantum dot infrared photodetector Rapid thermal annealing of GaN x As 1−x grown by radio-frequency plasma assisted molecular beam epitaxy and its effect on photoluminescenceWe report the effect of rapid thermal annealing on the valence-band splitting behavior of GaN x As 1−x films grown by molecular beam epitaxy. The light-and heavy-hole valence-band splitting induced by the elastic strain is observed in both photomodulated reflectance and photoluminescence spectra for as-grown GaN x As 1−x epilayers. The valence-band splitting energy increases with the nitrogen composition. This splitting is decreased with the increase of annealing temperature by the rapid thermal annealing temperature process. These properties have been well explained by strain relaxation model including both in-plane strain at GaAs/GaNAs interface and internal strain in GaNAs epilayer. These strain effects have been confirmed by x-ray diffraction and Raman measurements.