Optical properties of quasi zero-dimensional semiconductor quantum dots were studied by photoluminescence and Raman spectroscopy. The dependence of photoluminescence on substrate orientation and Raman spectra of single and multiple InAs/GaAs quantum dot structures are reported. The samples were grown on (100) oriented GaAs substrates without and with 3 degrees misorientation towards (110) by metal-organic vapor phase epitaxy in the Stranski-Krastanow regime. Strong dependence of photoluminescence properties of the quantum dot structures on substrate misorientation is shown. The InAs-related features an observed in the macro-Raman spectra and micro-Raman spectra. The effects of confinement, alloying and strain on PL and on phonon spectra are discussed.