Photoreflectance spectroscopy is used to study optical properties of GaNPAs for the intermediate band (IB) solar cell absorbers. The IB is created in GaNPAs by the incorporation of similar to 2% of N atoms and the required partial occupation of the intermediate band with electrons is realized by doping with Si donors. Undoped and p-type doped (Be doped) GaNPAs films are studied as a references. Observation of all three absorption bands: VB -> IB (a transition between the valence band and the IB), VB -> CB (a transition between the valence band and the conduction band), and IB -> CB (a transition between the IB and the conduction band), demonstrate that n-type doped GaNPAs layers act as intermediate band solar cell absorbers.