Abstract: There is described an optical pressure sensor comprising a sensor housing and an optical pressure cell mounted within the sensor housing and dividing the sensor housing into a first fluid space and a second fluid space. The optical pressure cell comprises a front side exposed to a pressure in the first fluid space and a back side exposed to a pressure in the second fluid space. The optical pressure sensor further comprises a fluid communication arrangement allowing pressure equalization between the pressure in the first fluid space on the front side and the pressure in the second fluid space on the back side of the optical pressure cell.

Abstract: There is described an optical pressure sensor comprising a sensor housing and an optical pressure cell mounted within the sensor housing and dividing the sensor housing into a first fluid space and a second fluid space. The optical pressure cell comprises a front side exposed to a pressure in the first fluid space and a back side exposed to a pressure in the second fluid space. The optical pressure sensor further comprises a fluid communication arrangement allowing pressure equalization between the pressure in the first fluid space on the front side and the pressure in the second fluid space on the back side of the optical pressure cell.

Abstract: A method and sensor for detecting a chemical substance in an analyte. An anisotropic material is subjected to the analyte. Light is passed through the anisotropic material and collected. A change of an optical anisotropy of the collected light is detected, the change being indicative of the chemical substance in the analyte.

Abstract: The present invention provides an optical sensor for monitoring current or power in a monitored element of a device such as a bridge-wire or hot-wire of electro-explosive devices. The optical sensor comprises an optical sensor made of semiconductor material. The semiconductor material comprises an absorption edge which is sensitive to a temperature variation. The semiconductor material is for placing in thermal contact with the monitored element of the device, whereby, when the current or power varies in the monitored element, it causes a variation in temperature in the semiconductor element and hence a spectral shift of the absorption edge which can be measured and which is representative of current and power variation.

Abstract: A diaphragm pressure measuring cell arrangement has a housing body at least partly made of sapphire material and a planar sapphire diaphragm with a peripheral edge joined by a first edge seal to the housing body to form a reference vacuum chamber. An outer surface of the diaphragm is exposed to a medium to be measured. A ceramic supporting body is attached to the back side of the housing body by sealing glass and includes a surface area overhanging that surrounds the housing body to form a first sealing surface. A tubular sensor casing incorporates the measuring cell for mounted the ceramic support body, the casing including an inside second surrounding sealing surface corresponding to the first sealing surface. A metal ring seal is between the sealing surfaces and a pressing member presses sealing surfaces together.

Abstract: A diaphragm pressure measuring cell arrangement has a housing body at least partly made of sapphire material and a planar sapphire diaphragm with a peripheral edge joined by a first edge seal to the housing body to form a reference vacuum chamber. An outer surface of the diaphragm is exposed to a medium to be measured. A ceramic supporting body is attached to the back side of the housing body by sealing glass and includes a surface area overhanging that surrounds the housing body to form a first sealing surface. A tubular sensor casing incorporates the measuring cell for mounted the ceramic support body, the casing including an inside second surrounding sealing surface corresponding to the first sealing surface. A metal ring seal is between the sealing surfaces and a pressing member presses sealing surfaces together.

Abstract: The present invention provides an optical sensor for monitoring current or power in a monitored element of a device such as a bridge-wire or hot-wire of electro-explosive devices. The optical sensor comprises an optical sensor made of semiconductor material. The semiconductor material comprises an absorption edge which is sensitive to a temperature variation. The semiconductor material is for placing in thermal contact with the monitored element of the device, whereby, when the current or power varies in the monitored element, it causes a variation in temperature in the semiconductor element and hence a spectral shift of the absorption edge which can be measured and which is representative of current and power variation.

Abstract: The invention concerns a tandem interferometer for temperature sensing. The low coherence interferometry (LCI) system comprises a polarization-based sensing interferometer comprising a birefringent crystal having a sensor temperature sensitivity and a birefringence dispersion, and a readout interferometer being either a Fizeau interferometer using an optical wedge or a polarization interferometer using a birefringent wedge. In one embodiment of the invention, the birefringent crystal has dispersion properties similar to that of the birefringent wedge or that of the optical wedge of the readout interferometer. The present invention also provides a signal processing method for correcting the dispersion effect and for noise filtering in LCI-based optical sensors of the tandem interferometer arrangement.

Abstract: The invention provides a method and a system for measuring a physical quantity by means of a tandem interferometer optical sensor system based on low-coherence interferometry. The system comprises a light system, a sensing interferometer and a polarization readout interferometer. The invention provides a polarization interferometer comprising a single birefringent wedge. The invention also provides for a dispersion-compensated optical sensor system. The invention also provides an interferometer sensitive to temperature that comprises a trajectory in a LiB3O5 crystal with an x-cut orientation.

Abstract: The invention concerns a tandem interferometer for temperature sensing. The low coherence interferometry (LCI) system comprises a polarization-based sensing interferometer comprising a birefringent crystal having a sensor temperature sensitivity and a birefringence dispersion, and a readout interferometer being either a Fizeau interferometer using an optical wedge or a polarization interferometer using a birefringent wedge. In one embodiment of the invention, the birefringent crystal has dispersion properties similar to that of the birefringent wedge or that of the optical wedge of the readout interferometer. The present invention also provides a signal processing method for correcting the dispersion effect and for noise filtering in LCI-based optical sensors of the tandem interferometer arrangement.

Abstract: A method and sensor for detecting a chemical substance in an analyte. An anisotropic material is subjected to the analyte. Light is passed through the anisotropic material and collected. A change of an optical anisotropy of the collected light is detected, the change being indicative of the chemical substance in the analyte.

Abstract: The invention provides a method and a system for measuring a physical quantity by means of a tandem interferometer optical sensor system based on low-coherence interferometry. The system comprises a light system, a sensing interferometer and a polarization readout interferometer. The invention provides a polarization interferometer comprising a single birefringent wedge. The invention also provides for a dispersion-compensated optical sensor system. The invention also provides an interferometer sensitive to temperature that comprises a trajectory in a LiB3O5 crystal with an x-cut orientation.

Abstract: The optical sensing device and the method thereof are for measuring a physical parameter. The device is to be connected to a light source which generates a multiple frequency light signal having predetermined spectral characteristics. The device comprises a Fabry-Perot interferometer through which the light signal is passed, an optical focusing device for focusing at least a portion of the light signal outgoing from the Fabry-Perot interferometer, and a Fizeau interferometer through which the focused light signal is passed. The Fabry-Perot interferometer includes two semi-reflecting mirrors substantially parallel to one another and spaced by a given distance so as to define a Fabry-Perot cavity having transmittance or reflectance properties which are affected by the physical parameter and which cause the spectral properties of the light signal to vary in response to the physical parameter.

Abstract: A resonator for the modal control of a laser with a gain medium having a non-circular cross-section in a plane perpendicular to the optical axis of the resonator. It has a graded reflectivity mirror as the output coupler. The graded reflectivity mirror consists of a partial reflector which has a reflectivity that varies gradually according to the position on the mirror's surface. The resonator is either astigmatic or the graded reflectivity mirror has a non circularly symmetric reflectivity profile or both. It allows the production of a good optical quality beam with an efficient energy extraction.

Abstract: The optical sensing device and the method thereof are for measuring a physical parameter. The device is to be connected to a light source which generates a multiple frequency light signal having predetermined spectral characteristics. The device comprises a Fabry-Perot interferometer through which the light signal is passed, an optical focusing device for focusing at least a portion of the light signal outgoing from the Fabry-Perot interferometer, and a Fizeau interferometer through which the focused light signal is passed. The Fabry-Perot interferometer includes two semi-reflecting mirrors substantially parallel to one another and spaced by a given distance so as to define a Fabry-Perot cavity having transmittance or reflectance properties which are affected by the physical parameter and which cause the spectral properties of the light signal to vary in response to the physical parameter.