Cristina Cadevall

Universitat Politècnica de Catalunya | UPC · CD6 - Centre for Sensors, Instruments and Systems Development

Imaging confocal microscopy (ICM) and focus variation (FV) are two of the most used technologies for 3D surface metrology. Both methods rely on the depth of focus of the microscope objective, which depends on its numerical aperture and wavelength of the light source to compute an optical section. In this paper we study how several methods of struc...

Most 3D metrological microscopes used today require a scanning through the optical axis, which is time consuming. The common techniques are Coherence Scanning Interferometry (CSI), Imaging Confocal Microscopy (ICM), and Focus Variation (FV). If one technique is good for smooth surfaces, it is not for rough ones, while the good for rough is too nois...

Recent advances in microscopy have made it possible to collect 3D topographic data, enabling more precise virtual comparisons based on the collected 3D data as a supplement to traditional comparison microscopy and 2D photography. Automatic comparison algorithms have been introduced for various scenarios, such as matching cartridge cases [1,2] or ma...

Surface engineering is a crucial technology in many industry sectors. It consists of adding functionality to a surface by coating or texturing it. Currently, coating technologies are mature and well established, but coatings suffer from limited durability and poor sustainability. Laser surface texturing is nowadays emerging due to the latest improv...

Imaging Confocal Microscopes (ICM) are highly used for the assessment of three-dimensional measurement of technical surfaces. The benefit of an ICM in comparison to an interferometer is the use of high numerical aperture microscope objectives, which allows retrieving signal from high slope regions of a surface. When measuring a flat sample, such as...

Stent quality control is a highly critical process. Cardiovascular stents have to be inspected 100% so as no defective stent is implanted in a human body. However, this visual control is currently performed manually and every stent could need tenths of minutes to be inspected. In this paper, a novel optical inspection system is presented. By the co...

Three-dimensional measurement of cylindrical surfaces is today accomplished with the use of an optical measurement system and dedicated rotational stages. The optical instrument is typically a sensor head that is able to provide 3D data with Confocal, Focus Variation or Coherence Scanning Interferometry, having every measurement technique its own b...

Implantable medical devices, such as stents, have to be inspected 100% so no defective one is implanted into a human body. In this paper, a novel optical stent inspection system is presented. By the combination of a high numerical aperture microscope, a triple illumination system, a rotational stage, and a CMOS camera, unrolled sections of the oute...

Stent quality control is a critical process. A high numerical aperture stent inspection system has been developed, composed by a rotary stage, a CMOS camera and a triple illumination arrangement. Unrolled sections of the outer, inner and sidewalls surfaces are obtained with high resolution. With this system, coatings thickness are also measured, cy...

Stent quality control is a critical process. Coronary stents have to be inspected 100% so no defective stent is implanted into a human body. Skilled operators currently perform the quality process control visually, and every stent could need tens of minutes to be inspected. In this paper, a novel stent optical inspection system is presented. By the...

The most common optical measurement technologies used today for the three dimensional measurement of technical surfaces are Coherence Scanning Interferometry (CSI), Imaging Confocal Microscopy (IC), and Focus Variation (FV). Each one has its benefits and its drawbacks. FV will be the ideal technology for the measurement of those regions where the s...

The most common optical measurement technologies used today for the three dimensional measurement of technical surfaces are Coherence Scanning Interferometry (CSI), Imaging Confocal Microscopy (IC), and Focus Variation (FV). Each one has its benefits and its drawbacks. FV will be the ideal technology for the measurement of those regions where the s...

Any optical system used for the surface finish measurement of an anodized part needs torecover thesignal from the air-ano layer, which is very weak in comparison to the signal on the ano-aluminum layer. Confocal based optical systems work very well for this purpose, but they have the drawback of having to use high numerical aperture objectives, onl...

The device (100) comprises means (200) for rotatably hold-ing and positioning at least one stent-like object (400) and means (30E, 30B) for illuminating at least inner and outer surfaces (I, 0) thereof comprising at least wide field epi illumination means (30E) and diffuse back illumination means (30B) for simultaneously illuminating the stent-like...

In this paper we introduce a new optical technique for the measurement of aspheric and free-form optics and moulds. This technique, called confocal tracking, consists on tracking the focus on the sample while it is moved along the horizontal XY axes. Unlike all single-point based techniques, confocal tracking images the surface, which makes it poss...

In this work, we present a new and fast easy-to-use device that allows the measurement of color and the detection of spots on the human skin. The developed device is highly practical for relatively untrained operators and uses inexpensive consumer equipment, such as a CCD color camera, a light source composed of LEDs and a laptop. The knowledge of...

Optical profiling techniques, mainly confocal and white light interferometry, have demonstrated to be suitable techniques for characterization of transparent thick films. Measurements are carried out by vertically scanning the upper and lower film interfaces. Thickness of the layer is determined from the two peaks in the confocal axial response or...

New material applications and novel manufacturing processes are driving a systematic rise in market demands concerning surface inspection methods and the performance of non-contact profilers. However, analysis of the specifications and application notes of commercial optical profilers shows that no single system is able to offer all the features a...

One of the most challenging applications of optical metrology is measuring the shape of the inner surfaces of nozzles such as those of fuel injectors, wiring dies and printheads. A current non-contact solution is confocal laser scanning microscopy (CLSM). However, the inner urfaces of the nozzles behave as though they were optically polished, which...

In segmented-mirror telescopes, wave-front discontinuities caused by segment misalignment are a major problem because they severely degrade optical performance. While angular misalignments are usually measured with deflectometric wave-front sensors (e.g., Shack-Hartmann sensors), a number of techniques have been proposed for the measurement of vert...

New material applications and novel manufacturing processes are driving a systematic rise in market demands concerning surface inspection methods and the performance of non-contact profilers. However, analysis of the specifications and application notes of commercial optical profilers shows that no single system is able to offer all the features a...

New material applications and novel manufacturing processes are driving a systematic rise in market demands concerning surface inspection methods and the performance of non-contact profilers. However, analysis of the specifications and application notes of commercial optical profilers shows that no single system is able to offer all the features a...

New material applications and novel manufacturing processes are driving a systematic rise in market demands concerning surface inspection methods and the performance of non-contact profilers. However, analysis of the specifications and application notes of commercial optical profilers shows that no single system is able to offer all the features a...

A device has been designed for off-line optical paper inspection and quality control of stripes and holes in the cigarette paper. Hardware description is first presented including main paper characteristics to be measured. Typical paper stripe and holes structures are then discussed with image processing and analysis considerations to discriminate...

One of the applications, which is considered to be very difficult to carry out with most optical imaging profilers, is the shape and texture measurements of structured surfaces obtained from the superposition of various micro or sub-micrometric layers of dissimilar materials. Typical examples are the architectures of microelectronics samples made u...

Present trends in the design of ground-based telescopes point towards the use of segmented primary mirrors. A major problem in this type of mirror is the achievement of proper segment positioning, as they have to be aligned with an accuracy of the order of a fraction of a wavelength for near-diffraction-limit telescope performance in the infrared....

A device has been designed based on the diffraction that will permit to analyze in an objective and quick form, the quality of ophthalmic lenses. This device situated in the line of production will improve the process of fabrication. The device is based on the phenomenon of the diffraction that takes place in the defects when impacting the light of...

In optical design is desirable that simulation and experimental set-up are as close as possible. We have developed our environment to simulate and to model complex optical systems (ROSA), which could contain non-optical elements. This environment is a robust tool for simulation, analysis and optimization of complex optical systems with an easy cust...

The surface metrology market today is moving towards non- contact modular computer-controlled systems for measuring and analyzing roughness, contour and topography. Since most of these systems require a great accessibility to the surface to be measured they can not be used for the metrology of surfaces with intricate geometries, difficult access an...