Abstract: There is described a terahertz illumination source for terahertz imaging.

Abstract: An imaging system that includes an image sensor and imaging optics is provided. The image sensor has a sensing surface and it captures images of a scene. The imaging optics is optically coupled to the image sensor and is configured to form the images of the scene onto the sensing surface of the image sensor. The imaging optics includes a sensor-adjacent optical element having an exit surface located in close proximity to the sensing surface of the image sensor. The exit surface of the sensor-adjacent optical element and the sensing surface of the image sensor are spaced apart by a gap having a gap width enabling evanescent-wave coupling from the exit surface to the sensing surface for light having wavelengths within the sensor spectral range.

Abstract: There is described a terahertz (THz) imaging device and method for imaging an object hidden underneath clothing. The THz imaging device is generally configured for illuminating a region of clothing with a THz illumination beam, collecting a return optical beam reflected from the region of clothing in response to the illumination, generating a THz image based on the collected return optical beam, and tracking a position and orientation of the THz imaging device as the THz image is generated. A plurality of complementary THz images are generated by repeating the steps of illuminating, collecting, generating and tracking for a plurality of points of view of the THz imaging device relative to the clothing. By registering these THz images to one another in a common coordinate system based on the tracked position and orientation, the THz imaging device can output a composite THz image representing the hidden object, if any.

Abstract: An optical component for transforming an input light beam having a Gaussian irradiance distribution into an output light sheet is provided. The optical component includes a first reflective surface extending around the central optical axis of the optical component and across an input light path of the input light beam, and reflects input light rays into transitional light rays defining a transitional light cone. A second reflective surface extends around the central optical axis and across a light path of the transitional light cone, reflecting the transitional light rays outwardly into output light rays defining the output light sheet. The first and second reflective surfaces are configured to distribute optical power within the output light sheet according to a Gaussian irradiance distribution transversally to the output light sheet. The output light sheet may be planar or conical.

Abstract: There is described a terahertz illumination source for terahertz imaging.

Abstract: An optical component for transforming an input light beam having a Gaussian irradiance distribution into an output light sheet is provided. The optical component includes a first reflective surface extending around the central optical axis of the optical component and across an input light path of the input light beam, and reflects input light rays into transitional light rays defining a transitional light cone. A second reflective surface extends around the central optical axis and across a light path of the transitional light cone, reflecting the transitional light rays outwardly into output light rays defining the output light sheet. The first and second reflective surfaces are configured to distribute optical power within the output light sheet according to a Gaussian irradiance distribution transversally to the output light sheet. The output light sheet may be planar or conical.

Abstract: A beam conditioning device includes a coherence-breaking module and a beam transforming module. The coherence-breaking module is configured to break a spatial coherence between beam components of the light beam and may include coherence-breaking mirrors having a structured pattern on their reflective surfaces. The beam transforming module may include a primary optical element and a secondary optical element and is configured to transform the spatial energy distribution and the footprint of the light beam. The beam conditioning device may be used to transform a Gaussian light beam into a flat-top light beam suitable for terahertz imaging applications, although other initial and/or final energy distributions may be considered.

Abstract: There is described an optical system for sensing the surface of an object. The system comprises: a light source for emitting at least one light beam centered on the optical axis of the system; a light reflector for reflecting the at least one incident light beam to generate at least two hollow conical light beams centered on the optical axis and having different opening angles, the at least two reflected hollow conical light beams for illuminating the surface; and an image capture device for imaging the illuminated surface.

Abstract: A beam conditioning device includes a coherence-breaking module and a beam transforming module. The coherence-breaking module is configured to break a spatial coherence between beam components of the light beam and may include coherence-breaking mirrors having a structured pattern on their reflective surfaces. The beam transforming module may include a primary optical element and a secondary optical element and is configured to transform the spatial energy distribution and the footprint of the light beam. The beam conditioning device may be used to transform a Gaussian light beam into a flat-top light beam suitable for terahertz imaging applications, although other initial and/or final energy distributions may be considered.

Abstract: There is described an optical system for sensing the surface of an object. The system comprises: a light source for emitting at least one light beam centered on the optical axis of the system; a light reflector for reflecting the at least one incident light beam to generate at least two hollow conical light beams centered on the optical axis and having different opening angles, the at least two reflected hollow conical light beams for illuminating the surface; and an image capture device for imaging the illuminated surface.

Abstract: There is provided a System and method of wavefront compensation in a synthetic aperture imaging system. A return signal data representative of a signal reflected by a target area to be imaged is received. A compensation phase figure corresponding to a wavefront compensation to be applied is provided. The compensation phase figure is added or otherwise applied to the phase pattern of the return signal data in order to obtain a compensated phase pattern. An optical beam is spatially modulated according to the compensated phase pattern to produce a modulated optical beam such that the compensation phase figure produces a wavefront compensation on the optical beam. An image of the target area is optically generated using the modulated optical beam.

Abstract: A method for determining a centerline for a triangulation-based optical profilometry system, compensating for the spatial variations of the reflectance of an object's surface. The method comprises providing a luminous line on the object, the luminous line being a triangulation line superposed with a compensation line; capturing an image of the triangulation line and of the compensation line; for each position along the imaged triangulation line, determining a transverse triangulation profile from the imaged triangulation line and a transverse compensation profile from the imaged compensation line; determining a transverse correction profile given by the reciprocal of the transverse compensation profile; multiplying the transverse triangulation profile with the transverse correction profile to obtain a corrected transverse triangulation profile; computing a center of the corrected transverse triangulation profile. The centers determined at positions along the triangulation line form the centerline.

Abstract: The gas dispensing apparatus comprises a réservoir (2) having an upper wall (5), a well (6) passing through the upper wall, and a gas dispensing device (8) located at least partially in the well (6) and having an external rigid portion (8a) facing the inner wall of the well. The gas dispensing apparatus comprises a résilient tubular élément (22) fitted into the well (6). The rigid portion (8a) of the device (8) is inserted therein. The well has an edge (34) extending outwardly and against which a stopping portion (30) of the tubular élément is flexed under action of the rigid portion of the device inserted into the tubular élëment. The flexed lower portion preferably defines an annular protubérance that prevents upward movement of the tubular élément relative to the well. A gas lighter of simplified construction and suitable for a brittle réservoir material such as amorphous polymers is obtained.

Abstract: A method for determining a centerline for a triangulation-based optical profilometry system, compensating for the spatial variations of the reflectance of an object's surface. The method comprises providing a luminous line on the object, the luminous line being a triangulation line superposed with a compensation line; capturing an image of the triangulation line and of the compensation line; for each position along the imaged triangulation line, determining a transverse triangulation profile from the imaged triangulation line and a transverse compensation profile from the imaged compensation line; determining a transverse correction profile given by the reciprocal of the transverse compensation profile; multiplying the transverse triangulation profile with the transverse correction profile to obtain a corrected transverse triangulation profile; computing a center of the corrected transverse triangulation profile. The centers determined at positions along the triangulation line form the centerline.

Abstract: There is provided a System and method of wavefront compensation in a synthetic aperture imaging system. A return signal data representative of a signal reflected by a target area to be imaged is received. A compensation phase figure corresponding to a wavefront compensation to be applied is provided. The compensation phase figure is added or otherwise applied to the phase pattern of the return signal data in order to obtain a compensated phase pattern. An optical beam is spatially modulated according to the compensated phase pattern to produce a modulated optical beam such that the compensation phase figure produces a wavefront compensation on the optical beam. An image of the target area is optically generated using the modulated optical beam.

Abstract: A dental tartar detection system (10), especially for detection of subgingival tartar (S), comprises a probe (12) adapted to be displaced along a tooth (T) an illumination system (14) for illuminating with an incident light a region on the tooth (T), a detection system (16) for collecting the light reflected thereat, and an analysis system (34) for providing a signal to an operator of the probe (12) when measurements on the reflected light in one or more predetermined range of wavelengths fall within any predetermined range of values that are characteristic of tartar (S). Typically, the detection of tartar (S) is achieved on the basis of the possible colors that tartar (S) can have such that the aforementioned one or more predetermined range of values cover wavelengths associated with colors of tartar (S).

Abstract: A dental tartar detection system (10), especially for detection of subgingival tartar (S), comprises a probe (12) adapted to be displaced along a tooth (T) an illumination system (14) for illuminating with an incident light a region on the tooth (T), a detection system (16) for collecting the light reflected thereat, and an analysis system (34) for providing a signal to an operator of the probe (12) when measurements on the reflected light in one or more predetermined range of wavelengths fall within any predetermined range of values that are characteristic of tartar (S). Typically, the detection of tartar (S) is achieved on the basis of the possible colours that tartar (S) can have such that the aforementioned one or more predetermined range of values cover wavelengths associated with colours of tartar (S).

Abstract: The gas dispensing apparatus comprises a reservoir (2) having an upper wall (5), a well (6) passing through the upper wall, and a gas dispensing device (8) located at least partially in the well (6) and having an external rigid portion (8a) facing the inner wall of the well. The gas dispensing apparatus comprises a resilient tubular element (22) fitted into the well (6). The rigid portion (8a) of the device (8) is inserted therein. The well has an edge (34) extending outwardly and against which a stopping portion (30) of the tubular element is flexed under action of the rigid portion of the device inserted into the tubular element. The flexed lower portion preferably defines an annular protuberance that prevents upward movement of the tubular element relative to the well. A gas lighter of simplified construction and suitable for a brittle reservoir material such as amorphous polymers is obtained.

Abstract: A dental tartar detection system (10), especially for detection of subgingival tartar (S), comprises a probe (12) adapted to be displaced along a tooth (T), an illumination system (14) for illuminating with an incident light a region on the tooth (T), a detection system (16) for collecting the light reflected thereat, and an analysis system (34) for providing a signal to an operator of the probe (12) when measurements on the reflected light in one or more predetermined range of wavelengths fall within any predetermined range of values that are characteristic of tartar (S). Typically, the detection of tartar (S) is achieved on the basis of the possible colors that tartar (S) can have such that the aforementioned one or more predetermined range of values cover wavelengths associated with colors of tartar (S).

Abstract: An image projector comprises a plurality of flexible reflective analog modulators (FRAMs), an illumination optics for focusing at least one light source thereon, a conversion optics for converting the variations in divergence of the beams reflected therefrom into variations in intensity, and a scanning mechanism coupled to a projection optics for displaying an image, constructed of intensity modulated light dots or pixels, on a screen. FRAM curvatures, responsible for determining the divergence of the reflected beams, and ultimately the intensity of each pixel, are varied by an actuation voltage that can be modulated using waveforms that minimize the FRAM response times. For multicolor images, three laser light sources operating at different wavelengths are used in conjunction with three linear FRAM arrays.