U.S. Philips Corporation

Alcatel N.v.

Marko Erman

Jean-Bernard Theeten

Nakita Vodjdani

Jean Le Bris

Philippe Autier

Claude E Hily

Jean-Louis Gentner

Jean-Francois Vinchant

Monique Renaud

Remi Gamonal

Jean-Marc Auger

Gerard Gillardin

A guide structure of a strip semiconductor active optical device includes a core structure extending as far as coupling surfaces. It includes at least three high index layers having refractive indices increased relative to that of the surrounding media to increase in these layers the power density of light to be processed, for example amplitude modulated, by the device. The high index layers have compositions such that they can apply this processing in response to electrical excitation and thicknesses greater than those of quantum wells. They are separated by lower refractive index dilutant layers with greater thicknesses such that a single propagation mode of light is guided by the guide structure. This mode has a thickness suited to coupling to an external optical component whilst confining the majority of the power of the light within the thickness of the core structure to favor the processing.

Semiconductor strip active optical device

An integrated semiconductor device including at least one optoelectronic switching element, which comprises:

Integrated semiconductor device including an optoelectronic switching

A semiconductor device comprising an integrated optical guide, which has at least one rectilinear part and one curved part, and comprising means for obtaining the confinement of the light in the guide in the curved part, which means include a groove provided along the edge of the guide in the region of the curve part, characterized in that these means also include a guide structure comprising a guiding layer and, overhanging the guiding layer, a ribbon in relief for determining the optical path followed by the light in the guiding layer, and in that these means moreover include a groove structure such that it has a constant depth, that its central part follows extactly the edge of the guiding ribbon in the curved part, that its ends are removing from the edge of this ribbon at the beginning and at the end of the curved part, that its bottom is disposed in the guiding layer at a level which does not reach the lower part of this guiding layer.

Semiconductor device comprising an integrated optical guide, which has

A device is described for characterizing wafers of semiconductor materials by photoluminescence with high spatial resolution and at low temperature, this device comprising at least:

Device for characterizing semiconductor samples by photoluminescence

An optical switching element including two optical guides constituted by linear parallel strips coupled through a distance d and made of semiconductor material having an index n.sub.1 on a semiconductor substrate having an index n.sub.o &lt;n.sub.1 and provided with electrodes E.sub.ii to carry out the switching of the light from one guide to the other, characterized in that the first guide G.sub.ii is connected on the one hand to an input IN.sub.i and on the other hand to a direct output I'.sub.i of the switching element, and in that the second guide H.sub.ii is provided beyond the zone of the electrodes E.sub.ii with a flat mirror M.sub.ii at 45.degree. with respect to its optical axis, which reflects the light into a guide H'.sub.ii perpendicular to H.sub.ii, in that H'.sub.ii is coupled through a distance d to a guide G'.sub.ii, the guides H'.sub.ii and G'.sub.ii being provided with electrodes E'.sub.ii to direct the light towards the output O.sub. i of the guide G'.sub.ii, and in that the systems of the guides G.sub.ii, H.sub.ii, H'.sub.ii, G'.sub.ii are covered by a planar confinement layer of a semiconductor material except the region Q.sub.ii of the mirror M.sub.ii. Application: switching matrix for telecommunication purposes.

Optical switching element comprising two parallel optical guides and

An integrated semiconductor arrangement of the coupling type between a photodetector D and a light wave guide G.sub.1, operating in a band of given wavelengths, containing on the surface of a semiconductor substrate S of a III-V compound one after the other a confining layer C.sub.0 of III-V compound and a transparent layer C.sub.1 of a III-V compound for the operating wavelengths having an index superior to that of the confining layer, the light waveguide G.sub.1 being realized in layer C.sub.1, and also containing an absorbing layer C.sub.3 of a III-V compound for the operating wavelengths having an index superior to that of the waveguide, in which layer C.sub.3 the photodetector is realized, characterized in that the absorbing layer C.sub.3 is deposited on top of the transparent layer C.sub.1 such that the photodetector is formed on the surface of the light wave guide G.sub.1 and coupled to the latter in parallel with its axis over a given coupling length L.sub.2 of which is a function the amount of light issued by the guide and received by the photodetector. This arrangement can also include, deposited between the transparent layer C.sub.1, hereinafter called first transparent layer and the absorbing layer C.sub.3, a second transparent layer C.sub.2 of a III-V compound for the operating wavelengths having an index lying between that of the first transparent layer C.sub.1 and that of the absorbing layer C.sub.3.

Integrated semiconductor arrangement of the coupling type between a

A spectroscopic ellipsometer comprises an illumination device having a focal point (F'.sub.2) for illuminating a surface of a sample (E) in accordance with a given angle of incidence and a device for analyzing the light reflected from the surface of the sample. The sample support comprises three translation plates (20,30,40) in accordance with three respective directions (T.sub.2, T.sub.3, T.sub.1). The translations in accordance with the first (T.sub.1) and second (T.sub.2) directions make it possible to realise cartographic representations of the sample (E) and the translation in accordance with the third direction (T.sub.3) makes it possible to cause a point on the surface of the same (E) to coincide with the focal point (F'.sub.2). Two plates (PT.sub.2, 12) rotating about the axes O.sub.1 and O.sub.2, respectively, parallel to the first (T.sub.1) and second (T.sub.2) directions and intersecting each other at the focal point (F'.sub.2) provide the possibility of orienting the sample (E) by means of rotation in two orthogonal planes about the focal point (F'.sub. 2).

Spectroscopic ellipsometer

An optical switching element including two parallel optical guides G.sub.1 and G.sub.2 each constituted by a strip of a semiconductor material having a refractive index n.sub.1 formed on a semiconductor substrate having a lower refractive index n.sub.0, the switching operation being obtained by the effect of voltages applied to electrodes arranged in the switching zone, characterized in that the latter is constituted by a strip of the same semiconductor material as the guides, which extends between the latter over a coupling length D between the abscissae -D/2 and +D/2 indicated on the orientated longitudinal axis of symmetry, and in that the electrodes are at least three in number, of which a first electrode permits of applying a reference voltage to the substrate, a second electrode extends substantially at the surface of the second guide from the abscissa -D to the abscissa -.epsilon., .epsilon. being small with respect to D, and a third electrode extends substantially at the surface of the first guide from the abscissa +.epsilon. to the abscissa +D, the second and third electrodes forming strips whose longitudinal axes of symmetry enclose with the optical axes of the second and first guides, respectively, an angle -.theta. defined on first approximation by the relation:

Optical switching element between two optical guides and optical

The invention relates to an optical sample illumination device for a spectroscopic ellipsometer of the rotating analyzer type. The image of the exit slit (F') of a monochromator is conjugated with a point (F'.sub.2) of a surface of a sample (E) by means of two spherical mirrors (M.sub.7 and M.sub.8). An astigmatism correction slit (F'.sub.15) is arranged in the proximity of the conjugate (F'.sub.1) of the exit slit(F') of the monochromator with respect to the spherical mirror (M.sub.7) and is arranged perpendicularly to this exit slit and to the optical path so that said correction slit is conjugated with the said point (F'.sub.2) through the spherical mirror (M.sub.8). A luminous spot without astigmatic errors is thus obtained.

Optical sample illumination device for a spectroscopic ellipsometer

A separation structure for selecting the propagation mode of the light waves in a light wave guide, the latter being constituted by a strip (100) of a semiconductor material having a first refractive index formed on a semiconductor substrate (10) of a material having a second refractive index lower than the first index and such that the light is confined in the strip forming the guide. The structure is arranged in the path of the light beam in such a manner that it de-limits in the guide on the one hand at least one region (G.sub.1), in which the propagation of the light wave is monomode, and on the other hand a region (G.sub.11), in which the propagation is bimode. According to the invention the said separation structure is formed by an abrupt variation of the dimension of the guide perpendicular to the substrate, the flat surface of the substrate being chosen as reference for the measurement of this dimension in such a manner that, by defining e.sub.1 as the dimension of the guide perpendicular to the substrate in the monomode region and e.sub.2 as its dimension in the bimode region, these dimensions are associated by the relation ##EQU1## in which .lambda. is the transported wavelength, n.sub.g is the refractive index of the light wave guide (100) and n.sub.S is the refractive index of the substrate (10).

Separation structure, optical switching element including such

An optical switching element including two parallel light wave guides, whose opposite walls are mutually separated by a small distance (d), the so-called coupling distance, each constituted by a strip of a semiconductor material formed on a semiconductor substrate having a refractive index lower than that of the guides, these guides each transporting a monomode wave and the switching being initiated by the effect of polarization means applied to the guides, characterized in that the strip constituting one of the guides (G.sub.1) designated as first guide is formed as a first uniform layer on the substrate (1), in that the strip constituting this guide is covered by a uniform intermediate layer (I) of a compatible semiconductor material, having an index lower than that of the guides and having a thickness which forms the coupling distance between the two guides, in that the strip constituting the other guide (G.sub.2) designated as second guide is formed as another uniform layer at the surface of the intermediate layer, and in that by the effect of the polarization means applied to the guides the light which is introduced into one of the guides parallel to its optical axis at a first distance from the substrate is caused to propagate through the other guide parallel to the optical axis of the latter at a second distance from the substrate, the assembly of the first guide forming with the second guide and with the intermediate layer a so-called stracked structure, whose longitudinal dimension is the coupling length.

Optical switching element between two light wave guides and optical

A coupling member between an input light wave guide transporting a main light beam and secondary light wave guides each transporting a part of the intensity of the main light beam. The coupling member is monolithically integrated with the wave guides on a semiconductor substrate. The coupling member comprises a plate having parallel surfaces perpendicular to the plane of the substrate. The plate has a refractive index different from that of the main light wave guide. The parallel surfaces of the plate form interfaces separating the propagation medium of the wave guides (I, R, T) from the propagation medium constituted by the plate.

Optical wave guides and coupling member monolithically integrated on a

A semiconductor device comprises a wave guide which permits propagation of light in the range of wavelengths between 0.9 and 1.6 .mu.m. This wave guide is formed on a crystallographic oriented substrate of monocrystalline semiconductor material from the group III-V covered with a layer of a dielectric material. Grooves are etched in the dielectric material according to the configuration chosen for the wave guide, and correspondingly into the substrate. The wave guide is obtained by anisotropic epitaxial growth of the III-V semiconductor material from the substrate in these grooves, and is bounded on its lateral and upper parts by crystallographic faces having a specific orientation relative to the plane of the substrate surface. The attenuation obtained for such wave guides is of the order of 1 dB/cm for light having a wavelength of 1.06 .mu.m.

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Paris, France

Marko Erman