Reflective Achromatic Fiber Collimators uses a 90⁰ off-axis ellipsoidal mirror to couple free space laser beam into fiber or vice versa. Focal length of reflective mirror is irrelevant with wavelength. That makes it an idea solution to achromatic aberration. Al, Ag and Au is optional to be deposited as reflective film.
- Aluminum averages greater than 90% reflectance from 200nm to the far infrared, except in the 750 – 900nm region where it averages around 85% reflectance.
- Silver coatings can offer better performance in the visible and NIR from 450nm to 2μm.
- For IR performance gold coatings offer high reflectivity of around 97% from 700nm up to 10μm.
