* Photo-reflectance measures differential reflectivities as small as one part per million, whereas ellipsometry and/or standard reflectance measure differential reflectivities on the order of one part per thousand. 
* Photo-reflectance spectra exhibits sharp derivative-like structures localized at interband transition energies, whereas ellipsometry and/or standard reflectance exhibit broad slowly varying spectra. 
* The photo-reflectance response at a particular wavelength typically arises from specific interband transitions confined to specific materials within the sample. 
* By using phase-locked detection methods, ambient (nonsynchronous) light does not influence photo-reflectance measurements.
* By using a laser probe beam, the refractive part of the photo-reflectance response can be isolated without the necessity to take spectroscopic data or perform a fit procedure.
* Laser photo-reflectance has been proven in statistical process control for microelectronics manufacturing for over three decades.