An optical device includes an array of lenses and a plurality of segments disposed under the array of lenses. The plurality of segments corresponds to a plurality of images. Upon tilting the device at different viewing angle, the array of lenses presents images sequentially. In some examples, individual ones of the segments can comprise specular reflecting, transparent, diffusely reflecting, and/or diffusely transmissive features. In some examples, individual ones of the segments can comprise transparent and non-transparent regions. Some examples can incorporate more than one region producing an optical effect.

A pupil-replicating lightguide includes an in-coupling grating structure, an out-coupling grating structure, and a phase compensation layer. The out-coupling grating structure has a spatially varying parameter such as grating duty cycle or grating thickness for evening out out-coupled distribution of light. The spatially varying out-coupling grating parameter disturbs the phase of the propagating image light. The phase compensation layer has a spatially varying optical thickness that compensates that disturbed phase to planarize an optical phase profile of out-coupled light, thereby improving a modulation transfer function of the pupil-replicating lightguide.

An optical device includes an array of lenses and a plurality of segments disposed under the array of lenses. The plurality of segments corresponds to a plurality of images. Upon tilting the device at different viewing angle, the array of lenses presents images sequentially. In some examples, individual ones of the segments can comprise specular reflecting, transparent, diffusely reflecting, and/or diffusely transmissive features. In some examples, individual ones of the segments can comprise transparent and non-transparent regions. Some examples can incorporate more than one region producing an optical effect.

A first waveguide portion receives light from an energy source in a fundamental transverse electric (TE.sub.00) mode. A mode converter converts a portion of the light to higher-order transverse electric (TE.sub.10) mode. A second waveguide portion receives the light at the TE.sub.10 mode and delivers the light to a near-field transducer that heats a recording medium in response thereto. An optical spatial mode filter prevents remnant light in the TE.sub.00 mode from affecting the recording medium while passing the light at the TE.sub.10 mode.