An optical ferrule for transmitting and propagating light having a predetermined wavelength includes a polymeric ferrule body having a fiber alignment feature for receiving an optical fiber, a redirecting side for redirecting light, and an output side window for exiting light therethrough. A multilayer anti-reflection film is disposed on the output side window and includes at least two first layers including titanium oxide and at least two second layers including silicon dioxide. At least one of the two first layers is thinner than an optimum thickness that would minimize reflection at the predetermined wavelength. Heating the optical ferrule at a temperature of about 85 degrees centigrade for at least five hours results in no, or very little, damage to the multilayer anti-reflection film.