Substrate Aberration Correction Techniques and Error Analysis

Aberrations such as spherical aberration, coma, astigmatism, etc., are inevitable in optical systems. Hence, numerous aberration correction schemes have been developed to cancel or minimize them. Diffractive optical systems are also susceptible to aberrations arising due to inaccurate design and fabrication errors. In this chapter, we present a ray tracing procedure that can be used to characterize and correct aberrations. This is followed by two basic aberration correction techniques to cancel the aberration introduced by the thickness of the substrate.