The imaging optics are modeled using a wave-optics approach which takes into account the finite resolution obtained with finite size optics. The user can vary the size of the aperture of the imaging optics by changing the f/number, which will automatically result in an adjustment of the image irradiance and resolution.

Image irradiance is determined using radiometric concepts and includes the effect of the off-axis cos-4^th effect, which results in a darkening of the corners with respect to the center of the image when a uniform object is imaged.

Finite resolution is calculated using an optical transfer function (OTF) approach, which is based on the finite aperture as determined by the f/number. To account for wavelength dependent behavior, the OTF is implemented in a spectral manner.

 The GUI allows the user to specify optical parameters, such as focal length, lens diameter, aperture, optical fall-off, transmittance, etc. Additional simulation of the optics within the sensor pixel itself, based on the number of metal layers, size and position of the photodetector on the substrate, and microlens properties can also be entered into the simulation.