ZrO2 films with variable refractive index by glancing angle deposition

When optical film is deposited at oblique angle incidences, the film becomes porously, and the film effective refractive index will decrease. Six porous ZrO2 films are fabricated by the glancing angle deposition (GLAD) technique with the different incidence angles. By changing the substrate tilt angle from 0 to 85 degrees, the film refractive index varies from 1.92 to 1.27.