An optical waveplate, comprising: a first birefringent film including optically anisotropic molecules arranged to form a first twist structure; a second birefringent film stacked with the first birefringent film and including optically anisotropic molecules arranged to form a second twist structure; and a third birefringent film stacked with the first birefringent film and the second birefringent film, the third birefringent film including optically anisotropic molecules arranged to form a third twist structure, wherein the optically anisotropic molecules at a first portion of the first birefringent film adjacent an interface between the first birefringent film and the second birefringent film are configured with a first azimuthal angle, wherein the optically anisotropic molecules at a second portion of the second birefringent film adjacent the interface are configured with a second azimuthal angle, wherein the first azimuthal angle is substantially the same as the second azimuthal angle, wherein the optical waveplate is configured to provide a substantially constant retardance over a design wavelength range, and the substantially constant retardance over the design wavelength range is a quarter-wave retardance or a half-wave retardance for a substantially normally incident light of a design wavelength in the design wavelength range, and at least one of the first birefringent film, the second birefringent film or the third birefringent film is configured to provide a retardance other than the quarter-wave retardance or the half-wave retardance for the substantially normally incident light of the design wavelength of the design wavelength range; and wherein the design wavelength is a center wavelength of the design wavelength range. a first birefringent film including optically anisotropic molecules arranged to form a first twist structure; a second birefringent film stacked with the first birefringent film and including optically anisotropic molecules arranged to form a second twist structure; and a third birefringent film stacked with the first birefringent film and the second birefringent film, the third birefringent film including optically anisotropic molecules arranged to form a third twist structure, wherein the optically anisotropic molecules at a first portion of the first birefringent film adjacent an interface between the first birefringent film and the second birefringent film are configured with a first azimuthal angle, wherein the optically anisotropic molecules at a second portion of the second birefringent film adjacent the interface are configured with a second azimuthal angle, wherein the first azimuthal angle is substantially the same as the second azimuthal angle, wherein the optical waveplate is configured to provide a substantially constant retardance over a design wavelength range, and the substantially constant retardance over the design wavelength range is a quarter-wave retardance or a half-wave retardance for a substantially normally incident light of a design wavelength in the design wavelength range, and at least one of the first birefringent film, the second birefringent film or the third birefringent film is configured to provide a retardance other than the quarter-wave retardance or the half-wave retardance for the substantially normally incident light of the design wavelength of the design wavelength range; and wherein the design wavelength is a center wavelength of the design wavelength range. the substantially constant retardance over the design wavelength range is a quarter-wave retardance or a half-wave retardance for a substantially normally incident light of a design wavelength in the design wavelength range, and at least one of the first birefringent film, the second birefringent film or the third birefringent film is configured to provide a retardance other than the quarter-wave retardance or the half-wave retardance for the substantially normally incident light of the design wavelength of the design wavelength range; and wherein the design wavelength is a center wavelength of the design wavelength range.