Optical Bonding

In larger lens systems, two or more components are often bonded together. This is because a single lens or prism refracts light to varying extents, resulting in a colour spectrum for a prism and chromatic aberration in lenses. These aberrations are corrected by combining two or more lenses made of different types of glass. Modern microscope, camera, smartphone and photography optics often consist of three to ten separate lenses.

The lenses and prisms are joined with a thin film of adhesive or optical cement, which acts as an achromatic lens and matches the lenses’ refractive index. So as not to impair the quality of the optics, these special adhesives and optical cements must have an extreme degree of purity and low shrinkage to prevent stress on the glass lenses.