Abstract:
Un interféromètre indépendant de la longueur d'onde comprend des moyens pour recevoir de la lumière (10) en provenance d'un champ optique, des moyens (BS1) pour séparer la lumière en deux faisceaux (11, 12), des moyens (BS2) pour combiner les deux faisceaux, et des moyens de dispersion (30) interposés dans la trajectoire (12) de l'un des deux faisceaux pour produire une déviation fonction de la longueur d'onde. Ces moyens de dispersion peuvent être un réseau de diffraction de transmission ou un réseau à réflection. Dans l'agencement représenté, les éléments optiques sont combinés dans un interféromètre Mach-Zehnder modifié. Lorsque l'interféromètre Mac-Zehnder classique est éclairé avec de la lumière cohérente, la séparation des franges d'interférence produites dans le plan d'interférence est inversement proportionnelle à la longueur d'onde. Grâce à l'introduction d'un élément de dispersion dans l'interféromètre décrit, le détecteur est sensibilisé à une séparation de franges prédéterminée. Un réticule mobile est placé devant un détecteur pour sensibiliser ce dernier à la configuration des franges.
Abstract:
Embodiments are disclosed relating to a refractively-scanning interferometer comprising an aperture that receives an incident light beam at a receiving angle, a beam splitter configured to split the incident light beam into a first beam and a second beam, a first and a second reflector arranged to reflect the first beam and second beam, respectively, towards a combining optical element, and a refractive Optical Path Difference (rOPD) assembly interposed between the beam splitter and the first reflector, wherein the rOPD Assembly refracts the first light beam an even number of times with induced phase discrepancy being a vector sum of a first phase discrepancy induced by a first refraction and a second phase discrepancy induced by a second refraction, the rOPD Assembly being configured such that the first phase discrepancy is substantially opposite in direction to the second phase discrepancy, a portion of the first and second phase discrepancies cancelling one another out to decrease magnitude of the phase discrepancy.
Abstract:
A Mach-Zehnder interferometer (MZI) structure based on a doubly-corrugated spoofed surface plasmon polariton (DC-SSPP) waveguide is presented. The dependence of phase change on the dielectric loading of the DC-SSPP structure causes the output from both arms to interfere and enhance features on the transmission spectrum of the MZI. The proposed MZI structure can be used for tag-free bio-molecular sensing. The highly localized electro-magnetic field at frequencies close to SSPP resonance is shown to reduce the sample amount needed to produce interference patterns without affecting the selectivity of the sensing structure.
Abstract:
An apparatus for measuring the duration of single short optical radiation lses, particularly laser radiation pulses, by means of autocorrelation and two-photon ionization, contains a Mach-Zehnder interferometer (BS1, BS2, M1, M2) as beam splitter means for generating from a single input radiation pulse (10) two coherent component pulses (14, 16) propagating along two component beam paths (18, 20) each of which contains a section (18a20a) passing through a meausring zone (22) where they overlap, further a two-photon ionization detector having a measuring zone (22) and collector electrode means (36) and counter-electrode means (38) at which an electric output signal is available depending on the number of charge carriers generated in the measuring zone when the component beam pulses overlap, and a measuring system connected to the electrode means (36, 38). The collector electrode means (36) contains a number of strip-type collector electrodes which are to each other and electrically separated from each other and are located in a plane essentially parallel to the two component beam paths ( 18a, 20a) in the measuring zone and are oriented in the longitudinal direction essentially in the direction of the component beam path sections (18a, 22a) passing through the measuring zone (22).
Abstract:
A physical property of a liquid or of any optical fiber is measured using optical fiber interferometer. A conductive material is disposed upon the surface of a region of a light transmitting optical fiber and the region having the conductive material is disposed in the liquid. Light energy is applied to one end of the fiber and transmitted light is received at the other end of the fiber. Electrical energy is applied to the conductive material disposed upon the surface of the fiber to heat the region of the fiber and cause a change in the optical path length of the light transmitted through the fiber. The physical property of the liquid or optical fiber is determined in accordance with the change in the optical path length of the received light caused by applying the electrical energy to the conductive material. A series of short energy pulses is provided and the average phase change is determined. The conductive material is gold and it encircles the fiber. The gold may be disposed on the jacket of the fiber or the jacket may be removed before disposing the gold.
Abstract:
A wavelength-independent-interferometer comprises means to receive light (10) from a field of view, means (BS1) to separate the light into two beams (11, 12), means (BS2) to combine the two beams, and dispersive means (30) interposed in the path (12) of one of the two beams to produce a wavelength-dependent shear. The dispersive means may be a transmission diffraction grating or a reflection grating. In the arrangement shown the optical elements are combined in a modified Mach-Zehnder interferometer. When the conventional Mach-Zehnder interferometer is illuminated with coherent light the separation of interference fringes produced in the interference plane is inversely proportional to the wavelength. By introducing a dispersive element in the invention the detector is sensitized to a pre-determined fringe separation. A moveable reticle is placed in front of a detector to sensitize the detector to the fringe pattern.
Abstract:
La présente invention concerne un système interférométrique comprenant des moyens de séparation de polarisation (10), des premiers moyens de conversion de polarisation (1 1 ), un interféromètre (2) de type Mach-Zehnder comprenant un premier (4) et un second (5) bras reliés entre eux par une première (6) et une seconde (7) extrémités de manière à ce qu'un premier et un second faisceaux (20, 21 ) de même polarisation parcourent l'interféromètre de manière réciproque suivant des directions de propagation respectivement opposées pour former un premier et un second faisceaux interférométriques (22, 23), des seconds moyens de conversion de polarisation (1 1 ) pour obtenir un faisceau interférométrique converti en polarisation (24), des moyens de combinaison de polarisation (10) et des moyens de détection (8) aptes à détecter un faisceau de sortie (25).
Abstract:
A wavelength-independent-interferometer comprises means to receive light (10) from a field of view, means (BS1) to separate the light into two beams (11, 12), means (BS2) to combine the two beams, and dispersive means (30) interposed in the path (12) of one of the two beams to produce a wavelength-dependent shear. The dispersive means may be a transmission diffraction grating or a reflection grating. In the arrangement shown the optical elements are combined in a modified Mach-Zehnder interferometer. When the conventional Mach-Zehnder interferometer is illuminated with coherent light the separation of interference fringes produced in the interference plane is inversely proportional to the wavelength. By introducing a dispersive element in the invention the detector is sensitised to a pre-determined fringe separation. A moveable reticle is placed in front of a detector to sensitise the detector to the fringe pattern.