Pyroistech

Colour human perception is not a universal standard

 Do you remember this dress picture (Figure 1)? It was posted and went viral in 2015, dividing the world and taking over all our feeds on social media [1]. However, while everyone was debating whether the dress was white and gold, or blue and black, this social experiment made us realise that the rest of the… Seguir leyendo Colour human perception is not a universal standard

Optical Biosensors based on Resonances

In this post we will describe the optical techniques based on resonances that can be used for biosensor interrogation apart from the ones seen in the initial post about biosensors.   When a waveguide, such as a cladding removed optical fiber, is coated by a thin-film, the propagation of the light is affected. Therefore, there may… Seguir leyendo Optical Biosensors based on Resonances

Optical Biosensors – Basic Concepts

In this post we will continue explaining some important concepts associated with biosensors (see also our previous post about biosensors), such as the specificity, the limit of detection (LOD), the dynamic range, the regeneration capability or the repeatability; that are not as simple to grasp as it may seem at first sight.   The specificity is the… Seguir leyendo Optical Biosensors – Basic Concepts

Optical Biosensors

In this post we will briefly describe some of the main optical techniques applied for biosensors interrogation but first it is important to clarify what we mean when we talk about biosensors and differentiate them from biometric sensors [1].   Concerning biometric sensors, they are used to measure body parameters without using any biohazardous chemicals. Body… Seguir leyendo Optical Biosensors

Sugar content (°Brix) measurement using fiber optic refractometers

Measurement of sugar percentage or ºBrix (1 ºBrix=1% sugar mass percent) is crucial in many applications, such as fruit juice, wine making, carbonated beverage industry and the sugar industry among others.   Different ºBrix sensors have been proposed for use in several areas, including industrial process monitoring, quality control in the food industry or biomedical… Seguir leyendo Sugar content (°Brix) measurement using fiber optic refractometers

Fiber Bragg Gratings – Propagation phenomena

Periodic perturbations of the optical fiber core refractive index along the fiber length can be obtained using different techniques, such as the exposure to an intense laser irradiation, arc discharge or mechanical deformations as it was also mentioned in one of our previous post about long period fiber gratings (LPFGs). This post will not be focused on the fabrication… Seguir leyendo Fiber Bragg Gratings – Propagation phenomena

LPFG Inscription Monitoring using SLED Broadband Light Source

SLED Broadband light sources can take advantage from broadband emission and high power as it is described in our previous post about SLEDs. These characteristics are very interesting in many different applications and particularly for Long Period Fiber Grating (LPFG) interrogation and monitoring as it is mentioned here.   LPFGs periodic structures were developed in parallel to… Seguir leyendo LPFG Inscription Monitoring using SLED Broadband Light Source

Broadband light source interferometry

The continuous emerging of novel manufacturing techniques, either top-down or bottom-up [1], enables a more and more precise control of the growth of structures at nanometric scale, which has motivated new and numerous applications in recent decades [2].   Particularly, the use of these novel manufacturing techniques for the fabrication of sensitive structures on fiber… Seguir leyendo Broadband light source interferometry

The role of evanescent field in optical fiber sensing

In this post we will briefly go through a theoretical introduction of evanescent field associated to optical fiber sensors and its applications to perform absorption measurements.   First, it is important to introduce the term of total internal reflection (TIR). TIR, consists of an optical phenomenon that occurs when a light beam hits the interface… Seguir leyendo The role of evanescent field in optical fiber sensing

Superluminescent diodes (SLD/SLED) applications

In one of our last articles (see article) we explained the basic principles of superluminescent diodes (SLD) operation. After understanding what means that the SLDs have a high spatial coherence and a low temporal coherence (see article), we can study their applications. Nowadays, the most important ones are the following:   Optical coherence tomography (OCT):   Is a high-resolution (µm… Seguir leyendo Superluminescent diodes (SLD/SLED) applications