A wideband diffractive component capable of diffracting an incident beam exhibiting a wavelength lying in a diffraction spectral band, the diffractive component elementary areas arranged on a surface, each area belonging to a type indexed by an index i lying between 1 and n, with n greater than 1, index i corresponding to blaze wavelength λi of index i, the blaze wavelengths lying in the diffraction spectral band, an elementary area of type i comprising microstructures having at least a size less than 1.5 times the blaze wavelength of index i, the microstructures arranged to form an artificial material exhibiting an effective index variation such that an elementary area of type i constitutes a blazed diffractive element at the blaze wavelength λi of index i, the different values of the blaze wavelengths and the proportion of surface area occupied by the areas of a given type a function of a global diffraction efficiency desired in the diffraction spectral band.

The present invention relates to a mobile terminal comprising a lighting device. The lighting device according to one embodiment of the present invention comprises multiple light-emitting elements and a diffractive optical element (DOE) for diffracting a part of the light which has been output from each of the multiple light-emitting elements, wherein the light, which has been output from the multiple light-emitting elements and has passed through the diffractive optical element, comprises multiple first kinds of light not diffracted by the diffractive optical element and multiple second kinds of light diffracted by the diffractive optical element, and the diffractive optical element diffracts the part of the light output from the multiple light-emitting elements such that at least some of the multiple second kinds of light is radiated into an area formed by connecting the multiple first kinds of light.

An example head-mounted display device includes a plurality of optical elements in optical communication. The optical elements are configured to project an image in a field of view of a user wearing the head-mounted display device. A first optical element is configured to receive light from a second optical element. The first optical element defines a grating at along a periphery of the first optical element. The grating includes a plurality of protrusions extending from a base portion of the first optical element. The protrusions include a first material having a first optical dispersion profile for visible wavelengths of light. The grating also includes a second material disposed between at least some of the plurality of protrusions along the base portion of the first optical element. The second material has a second optical dispersion profile for visible wavelengths of light.

An example head-mounted display device includes a plurality of optical elements in optical communication. The optical elements are configured to project an image in a field of view of a user wearing the head-mounted display device. A first optical element is configured to receive light from a second optical element. The first optical element defines a grating at along a periphery of the first optical element. The grating includes a plurality of protrusions extending from a base portion of the first optical element. The protrusions include a first material having a first optical dispersion profile for visible wavelengths of light. The grating also includes a second material disposed between at least some of the plurality of protrusions along the base portion of the first optical element. The second material has a second optical dispersion profile for visible wavelengths of light.

A diffractive light projection device includes a light source and a diffractive optical module. The light source emits a light beam. After the light beam passes through the diffractive optical module, a diffractive light is outputted from the diffractive optical module. The diffractive optical module includes plural diffractive optical elements, which are arranged in a stack form and made of different materials. Consequently, a usable wavelength range of the light beam is expanded. Since the usable wavelength range of the light beam to be incident on the diffractive optical module is expanded, the degree of freedom for designing the diffractive optical module is increased.

An example head-mounted display device includes a plurality of optical elements in optical communication. The optical elements are configured to project an image in a field of view of a user wearing the head-mounted display device. A first optical element is configured to receive light from a second optical element. The first optical element defines a grating at along a periphery of the first optical element. The grating includes a plurality of protrusions extending from a base portion of the first optical element. The protrusions include a first material having a first optical dispersion profile for visible wavelengths of light. The grating also includes a second material disposed between at least some of the plurality of protrusions along the base portion of the first optical element. The second material has a second optical dispersion profile for visible wavelengths of light.

Unpolarized broadband reflectors enabled by a serial arrangement of a pair of polarized subwavelength gratings are disclosed. Device illustrations include partially-etched crystalline-silicon films on quartz substrates and amorphous silicon films on glass. The individual reflectors exhibit extremely wide spectral reflection bands in one polarization. By arranging two such reflectors sequentially with orthogonal periodicities, there results an unpolarized spectral band that exceeds those of the individual polarized bands. In the prototypes disclosed, there results zero-order reflectance exceeding 97% under unpolarized light incidence over a 500-nm-wide wavelength band. This wideband represents a 44% fractional band in the near infrared spectral band. The elemental polarization-sensitive reflectors based on one-dimensional resonant gratings have simple design, robust performance, and are straightforward to fabricate. Hence, this technology is a promising alternative to traditional multilayer thin-film reflectors especially at longer wavelengths of light where multilayer deposition may be infeasible or impractical.

A diffractive optical element including microstructures, along a surface of an optical material, having a phase profile to diffract input illumination into structured light of a plurality of different diffraction orders; wherein the phase profile is at least partially phase unwrapped is disclosed. Methods of generating the diffractive optical element is also disclosed.

Diffractive waveplate lenses, mirrors, devices, systems and methods for performing imaging over a broad spectral band in imaging systems, such as but not limited to astronomical imaging, surveillance imaging, and in communication systems, such as laser communication systems. Corrector mirrors are used with a flat diffractive wave diffractive waveplate lens so that chromatic aberrations of the diffractive waveplate lens are reduced with the imaging system.

The present invention relates to a mobile terminal comprising a lighting device. The lighting device according to one embodiment of the present invention comprises multiple light-emitting elements and a diffractive optical element (DOE) for diffracting a part of the light which has been output from each of the multiple light-emitting elements, wherein the light, which has been output from the multiple light-emitting elements and has passed through the diffractive optical element, comprises multiple first kinds of light not diffracted by the diffractive optical element and multiple second kinds of light diffracted by the diffractive optical element, and the diffractive optical element diffracts the part of the light output from the multiple light-emitting elements such that at least some of the multiple second kinds of light is radiated into an area formed by connecting the multiple first kinds of light.