- Type A (aspheres)
- Type M (laser monochromats or achromat),
- Type RGBV (apochromat)
Lens Types for fiber optic components
Lens Types
Asphere
Laser monochromat or achromat
Apochromat
RGBV optics (achromats and even apochromats) are designed for optimum multiple wavelength coupling/collimation by minimizing the chromatic focal shift for all wavelengths from 400 to 660 nm. They are corrected for spherical aberrations and designed in such a way that it leads to a diffraction-limited beam with an M2<1.05. A recollimation for wavelengths 400 to 660 nm is not necessary. By minimizing the chromatic focal shift the polychromatic beams are focused at the fiber end-face onto a common point reducing otherwise significant coupling losses. It is not suitable for UHV applications.
AR Coating, Transmission and Working Range
The AR coating does not necessarily define the wavelength range in which an optics can be used. When it comes to short wavelengths (UV) or longer wavelengths (IR), an optics internal or glass transmission plays a key role, as it can significantly reduce the amount of light passing through the optics. When it comes to doublet optics also the cement between the single lenses must be considered.
This is why we have introduced the working range, which considers cement and both glass transmission as well as AR coating. Please note that all optics are always AR coated for the complete working range (unless described as uncoated). The optics used in our products are the same as before, we only want to describe them more accurately.
When it comes to glass transmission the threshold is 2% internal transmission loss, unless explicitly specified otherwise. Details about the AR coating (rest reflectivity over wavelength) can be found in the AR coating plot, details about the internal glass transmission (transmission over wavelength) in the transmission plot. Both plots can be found in the downloads section of the respective product webpage.