Chromatic Correction

Chromatic aberration is caused by glass that has a different refractive index for each wavelength. Generally, the refractive index of glass is higher for shorter wavelengths. Accordingly, in a convex lens, short wavelength light focuses on a closer position to the lens, and long wavelength light focuses at a distal position from the lens. Concave lenses diffuse shorter wavelength light. Therefore, chromatic correction (CC) is performed by combining convex and concave lenses so that red and blue light focus on the same position below. The unique manufacturing technology of X Line ultra-thin lenses allows more lens elements to be fitted into the objective, leading to unmatched chromatic correction.

Chromatic aberration comparison of single lens and compound lens.

With lenses manufactured using conventional technology, the chromatic correction of Apochromat objectives ranges from 435–656 nm. Because of this range, the focus position is not colocalized for short wavelengths (< 435 nm) and long wavelengths (> 656 nm). By contrast, X Line objectives have a chromatic correction range of 400–1000 nm while maintaining very high NAs of up to 1.45.

X Line Axial Chromatic Aberration

Comparing the focus position in the 400–1,000 nm wavelength range (smaller is better)

Axial chromatic aberration compared for PSF fluorescent beads (405 nm, 633 nm)

Axial chromatic aberration compared for PSF fluorescent beads (405 nm, 633 nm). Only X Line shows the correct colocalization of the signal.