Microsphere embedded phantoms are widely used to characterize point spread functions (PSF), which are generally employed to evaluate resolution performance of optical imaging systems such as optical coherence tomography (OCT). A convenient method based on surface silanization of silicon wafer is employed to prepare point spread function phantoms by mixing 1 μm in diamter polystyrene microspheres with transparent polymer-polydimethylsiloxane (PDMS). Compared to conventional methods employing moulding and polishing, the rapid prototyping process based on PDMS provides a faster, less expensive alternative. Detailed fabrication procedures as well as specific designs are described, and the produced PSF phantoms are utilized for performance assessment of a spectral domain OCT system. By analyzing the point spread functions, 6.8 μm axial resolution and 14.3 μm lateral resolution are obtained and in good agreement with the theoretically predicted values. For comparison, images of the standard-size microspheres are provided by measuring the PSF phantoms with optical microscope.