Plano-concave lens, N-BK7, Ø 22.4 mm, f = -100 mm, mounted, ARB2-NIR

Plano-concave singlet in N-BK7, Ø 22.4 mm, focal length -100 mm, in a mount. ARB2-NIR broadband AR coating. Negative focal length: diverges the beam, for beam expanders and to shorten system length.