A wideband diffractive component diffracting an incident beam exhibiting a wavelength in a diffraction spectral band is provided. The diffractive component elementary areas are 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, corresponding to blaze wavelength i of index i, the blaze wavelengths lying in the diffraction spectral band. An elementary area of type i includes microstructures sized less than 1.5 times the blaze wavelength of index i, arranged to form an artificial material exhibiting an effective index variation where an elementary area of type i constitutes a blazed diffractive element at the blaze wavelength i 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.

An optical element is disclosed. The optical element comprises: a first phase shift mask formed on a first optical material and constituted to generate a positive phase shift, and a second phase shift mask formed on a second optical material and constituted to generate a negative phase shift, wherein the phase shift masks are arranged serially on an optical axis, and wherein a refractive index of at least one of the first and second optical materials varies with the temperature at a rate of at least 50?10.sup.?6 per degree Kelvin.

An optical element is disclosed. The optical element comprises: a first phase shift mask formed on a first optical material and constituted to generate a positive phase shift, and a second phase shift mask formed on a second optical material and constituted to generate a negative phase shift, wherein the phase shift masks are arranged serially on an optical axis, and wherein a refractive index of at least one of the first and second optical materials varies with the temperature at a rate of at least 50?10.sup.?6 per degree Kelvin.

An object of the present application is to thin a thick lens used in an automobile headlamp optical system and a projector lighting optical system while maintaining the optical properties of the lens. A diffractive lens includes, on at least one surface, an optical surface with a plurality of areas defined by a plurality of steps. A blaze wavelength of the diffractive lens is within a wavelength spectral range of a light source used. An optical path difference between adjacent areas at the blaze wavelength is larger than a coherence length of the light source. The diffractive lens substantially acts as a Fresnel lens at a wavelength other than the blaze wavelength.

An optical element is disclosed. The optical element comprises: a first phase shift mask formed on a first optical material and constituted to generate a positive phase shift, and a second phase shift mask formed on a second optical material and constituted to generate a negative phase shift, wherein the phase shift masks are arranged serially on an optical axis, and wherein a refractive index of at least one of the first and second optical materials varies with the temperature at a rate of at least 5010.sup.6 per degree Kelvin.

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 invention relates to optical devices comprising a transparent substrate and a first transparent grating layer on the substrate, the grating layer comprising periodically alternating zones having different refractive indices. According to the invention, the device comprises a second transparent grating layer located on top of the first grating layer and also comprising periodically alternating zones having different refractive indices so that the zones of the first grating layer having higher refractive index are at least partly aligned with the zones of the second grating layer having lower refractive index and vice versa, the second grating layer reducing the amount of light diffracted to non-zero transmission orders. The invention allows for reducing the so-called rainbow effect for example in head-up displays (HUDs).

There is immense scientific interest in the properties of resonant thin films embroidered with periodic nanoscale features. This device class possesses considerable innovation potential. Accordingly, we report unpolarized broadband reflectors enabled by a serial arrangement of a pair of polarized subwavelength gratings. Optimized with numerical methods, the elemental gratings can be fabricated in various materials systems. Illustrative examples provided consist of a partially-etched crystalline-silicon films on a quartz substrate and amorphous silicon films on glass. The resulting reflectors exhibit extremely wide spectral reflection bands in one polarization. By arranging two such reflectors sequentially with orthogonal there results an unpolarized spectral band that exceeds those of the individual polarized bands. In the prototypes disclosed herein, 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