Université Jean-monnet

Sick | Stegmann Gmbh

Other

Olivier Parriaux

Nikolay Lyndin

Reinhold Mutschler

Florent Pigeon

Thomas Kaempfe

Yves Jourlin

Alexandre Tishchenko

Jean-François Bisson

Alexander V Tishchenko

Swetlen Tonchev

The planar polarization transformer for a normally incident optical wave or beam having a given vacuum wavelength &#x3bb; comprises an optical planar grating between a cover medium of refractive index nand an optical substrate of refractive index n, this planar grating defining a binary index modulation or corrugation of substantially rectangular profile with periodic ridges. This polarization transformer is characterized in that the ridge refractive index nis larger than the substrate refractive index n, the grating period &#x39b; is larger than 0.4&#xb7;&#x3bb;/n, the substrate refractive index nis smaller than 2.7&#xb7;n, and the index modulation or corrugation is designed such that, according to the grating mode dispersion equation, the effective index of the mode TEis larger than the substrate index nand the effective index of the mode TMis larger than the cover refractive index and smaller than the substrate index.

Planar polarization transformer

Disclosed is a Rotation sensor with a light source, a light detector, an internal part having a first lateral surface, which is globally cylindrical and convex, and an external part having a second lateral surface which is globally cylindrical and concave. The first and second lateral surfaces both have a same central axis defining a rotation axis for a relative rotation between the internal part and the external part the angle of which this rotation sensor can measure. A first grating is arranged at the first lateral surface with its grating lines parallel to the rotation axis, and a second grating is arranged at the second lateral surface with its grating lines parallel to said rotation axis.

Cylindrical grating rotation sensor

A polarizing mirror device including an optical substrate () of real refractive index n; a dielectric multilayer mirror (), composed of dielectric layers of low and high refractive index; and a corrugated grating layer () of local period &#x39b; at the side of a cover medium of refractive index n. The local period &#x39b; is selected such that upon substantially normal incidence of an incident wave at wavelength &#x3bb; from the cover medium there is no diffraction order other than the 0reflected order in the cover medium, such that the field of the +1and &#x2212;1orders diffracted into the layers of the multilayer and into the optical substrate have a non-evanescent propagating character, and such that the respective angles under which the +1and &#x2212;1orders propagate in each layer of said multilayer have an absolute value larger than or equal to the angle corresponding to the angular band edge of the central TM reflection band and, if a central TE reflection band of finite angular width exits, smaller than the angle corresponding to the angular band edge of this central TE reflection band in the angular spectrum of the multilayer at the wavelength &#x3bb; with a fictive incident medium having the index of the considered layer of this multilayer.

Diffractive polarizing mirror device

For increasing the power emitted by surface emitting lasers and for improving the spatial coherence of the laser beam, emitted in particular by disk lasers, microchip lasers and VCSELs having a relatively wide emitting area, the invention proposes to select a low order transverse cavity mode by means of a mirror structure () of high reflectivity, and of high angular selectivity. The mirror structure comprises a multilayer () receiving the optical beam () and a resonant grating mirror () following the multilayer and arranged for highly reflecting the optical beam in a narrow angular range at each side of a determined incidence angle.

Mirror structure and laser device comprising such a mirror structure

The invention relates to an information carrier (), having a metal layer () with at least one track () in which marks () are disposed, which can be detected by means of light of a central wavelength (&#x3bb;) which is emitted by a light source () and which is incident upon the information carrier () at an angle (&#x3b8;), and from which the position of the information carrier () can be derived, wherein the marks () are formed by areas () which are structured at least by first structures () of a lattice period (&#x39b;) which are disposed on the back side () of the metal layer () and/or on the front side () of the metal layer (), and wherein the lattice period (&#x39b;) of the first structures () satisfies the equation &#x39b;=&#x3bb;/(n*&#x2212;sin(&#x2296;)) or &#x39b;=&#x3bb;/(n*+sin(&#x2296;)), wherein &#x3bb; is the central wavelength of the used light, &#x2296;is the angle at which the light of the light source () is incident upon the information carrier () and n* is the effective index of a plasmon mode along the metal layer ().

Information carrier

The invention concerns a light reflecting element comprising a substrate ( ), a multilayer mirror ( ) and optical coupling means ( ) comprising a diffraction grating ( ); whereby the reflection coefficient of one polarization is damped without damping the reflection coefficient of the orthogonal polarization over a broad wavelength range and with a large tolerance on the optogeometrical parameters of the device.

Growing community of inventors

Saint-Etienne, France

Olivier Parriaux