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:
Provided is an optical pulse-generator and an optical pulse-generating method which are capable of generating an optical pulse train with an arbitrary pattern. An optical pulse-generator 1 includes a first optical modulator 21 configured to modulate input light using a first modulation signal SIG1 to generate optical pulses, a second optical modulator 41 configured to perform a modulation operation using a second modulation signal SIG2 synchronizing with the first modulation signal SIG1 and having a signal pattern that is set to output only specific part of the optical pulses, and a dispersion compensator 30 configured to compensate a chirp of the optical pulse output from the first optical modulator 21.
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 interferometric system includes a polarization separation element (10), a first polarization conversion element (11), a Mach-Zehnder interferometer (2) including a first (4) and second (5) arms connected to one another by a first (6) and second (7) ends in order for a first and second beams (20, 21) having the same polarization to pass through the interferometer in a reciprocal manner in opposite directions of propagation, respectively, so as to form a first and second interferometric beam (22, 23), a second polarization conversion element (11) for obtaining an interferometric beam (24), the polarization of which is converted, a polarization-combining element (10), and a detection element (8) suitable for detecting an output beam (25).
Abstract:
Apparatus is provided to detect electromagnetic radiation, in which a radion-absorbing element is disposed on a short section of an optical waveguide to provide a thermal interface therebetween. Radiation is absorbed by the element, which thereby heats the waveguide, causing it to change its optical pathlength in proportion to the radiation absorbed. Interferometer apparatus is connected to measure this change in optical pathlength as a change in the interference condition. This device is highly sensitive and can be operated at room temperature.
Abstract:
A passive quadrature phase detection system for coherent fiber systems includes first and second optical detectors positioned to receive an output signal from the output end of an optical signal apparatus such as an interferometer, or the like. The optical signal from the apparatus includes light propagating in two propagation modes. As the light propagates away from the output end of the apparatus from the near field to the far field, the light in the two modes undergoes a relative phase shift of .pi./2 in accordance with the Guoy effect. The two detectors are positioned such that the first detector detects the intensity of light resulting from the interference between the two modes in the near field of the output signal, and such that the second detector detects the intensity of light resulting from the interference between the two modes in the far field of the output signal. The additional .pi./2 phase difference introduced between the two modes as the light propagates from the near field light to the far field causes the detected light intensities to be in phase quadrature. Electrical signals proportional to the detected light intensities can be processed to determine changes in the phase difference between the two modes within the apparatus. In preferred embodiments, the detection of the near field light intensity is accomplished at a position optically displaced from the output end of the apparatus.
Abstract:
For the detection of the wavefront of a beam, based on a Mach-Zehnder interferometric configuration, synchronous detection - which replaces a temporal scan or a spatial dimension of the array of sensors - is obtained by means of frequency coding of the fringes present in the function I(x,y).
Abstract:
The present invention relates to a method for fine-tuning an optical device (10, 110, 210) comprising two Mach Zehnder devices being detuned with respect to each other. The invention also relates to an optical device (10, 110, 210) comprising two Mach Zehnder devices. A first optical delay (ΔL opt ) is introduced into a path (12, 112, 212) common to both Mach Zehnder devices in order to introduce a path length difference which is common to both Mach Zehnder devices and which amounts to said first optical delay (ΔL opt ). A second optical delay (δl) is introduced into at least one path which belongs to only one of the Mach Zehnder devices, in order to detune the two Mach Zehnder devices with respect to each other.
Abstract:
Interféromètre comportant un ensemble intégré (52) et un miroir de mesure (54) séparé de cet ensemble intégré par une région de mesure (56). Cet interféromètre est caractérisé par le fait qu'il comprend des moyens (82) d'égalisation des chemins optiques, dans ledit ensemble intégré, d'un faisceau lumineux de mesure (68) et d'un faisceau lumineux de référence (70).
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.