The invention provides a method for detecting objects in samples. The sample is held in the transmission path of light source to a detector, whereby light from the light source interacts with objects in the sample. The patterns of light incident on the detector subsequent to its interaction with the objects are directly used to determine the presence of objects in the sample.

A holographic projection system includes: a light source configured to generate a first light beam; a spatial light modulator configured to receive the first light beam and project a second light beam; a diffuser configured to rotate and including multiple regions, where two or more of the regions include respective down conversion materials, and where each of the respective down conversion materials convert a color of the second light beam to another color; and at least one control module configured to generate an image, encode the spatial light modulator with multiple holograms to generate the second light beam including instances of the image, and control rotation of the diffuser to display and overlay the instances of the image to provide a resultant image.

A holographic projection system includes: a light source configured to generate a first light beam; a spatial light modulator configured to receive the first light beam and project a second light beam; a diffuser configured to rotate and including multiple regions, where two or more of the regions include respective down conversion materials, and where each of the respective down conversion materials convert a color of the second light beam to another color; and at least one control module configured to generate an image, encode the spatial light modulator with multiple holograms to generate the second light beam including instances of the image, and control rotation of the diffuser to display and overlay the instances of the image to provide a resultant image.

A holographic projector includes an illumination system arranged to illuminate a hologram displayed on the pixel area of a spatial light modulator to form a holographic wavefront, and further includes a waveguide including an input port arranged to receive the holographic wavefront and a pair of opposing surfaces arranged to waveguide the holographic wavefront. A first surface of the pair of opposing surfaces is partially reflective-transmissive such that a plurality of replicas of the holographic wavefront are emitted therefrom. The illumination system includes a light source arranged to emit diverging light and a first collimating lens arranged to collimate the light. The collimated light has a varying intensity profile, in at least one dimension. The illumination system is configured such that the pixel area is contained within an area delineated by the width of the intensity profile of the collimated light at half the maximum intensity of said intensity profile.

For a given region of a liquid crystal display (LCD) device and a given viewing direction, colour values of an imaginary light ray that originates from at least one virtual object along the given viewing direction and that is to be presented by the given region of the LCD device are determined. This LCD device includes a backlight unit that is configured to produce collimated light rays. A drive signal is generated and sent to control the given region of the LCD device to emit light rays having the colour values of the imaginary light ray. A corresponding portion of an active optical element arranged on an optical path of the backlight unit is controlled, to direct the light rays along the given viewing direction. The aforesaid steps are repeated for respective ones of different viewing directions, by employing temporal multiplexing.