<b>Effects of specimen refractive index on confocal imaging</b>

Abstract

The aberrations introduced when focusing within a specimen with a refractive index equal to that of water using an oil‐immersion objective are investigated theoretically. The peak intensity in the confocal point spread function drops by a factor of two for focusing less than 10 μm into the specimen. The effects on scaling of dimensions in the resulting images are discussed. The image exhibits an axial stretching by a factor of about 1.12.