English Posts

How dark is the night sky? To this question we tried to give an “exact” answer by trying to measure the brightness of the night sky using a sensor based on a photomultiplier. Of course it is mandatory, if you want to get significant results, position yourself in places not …

The Equipment The latest addition to the Micod family is the universal PMT preamplifier. The device, housed in a metal package, consists of a CSP followed by a buffer stage. What is striking about this device is its versatility : there is in fact the possibility of modifying the hardware …

The Optical Fiber Optical fibers are filaments of glassy or polymeric materials, made in such a way as to be able to carry light inside them (guided propagation), and which find important applications in telecommunications, medicine, sensors and lighting technology. Optical fibers typically include a core surrounded by a transparent cladding material with a …

The Absorption Photometer The absorption photometer is based on the photodiode photometer already described in the post: PSoC based Photometer. To use the photometer in absorption measurements we have prepared a cell-holder cell with two side openings. In an opening the photodiode is inserted, connected to the photometer, in the …

Introduction The optical table is an invaluable tool for the realization of any optical experience. In practice it is a platform used to support systems for optical experiments. In optical systems, the alignment of each component must be extremely accurate, think for example of an interferometer. Even small vibrations or …

Introduction In this post we want to describe the realization of a simple “general purpose” photometer, based on a photodiode sensor and on a Cypress PSoC5LP microcontroller. The photometer is the instrument that measures the intensity of a light emission, its applications range in many different sectors, including chemical and …

Chemiluminescence Chemiluminescence is the emission of electromagnetic radiation, particularly in the visible and near infrared, which can accompany a chemical reaction. Considering a reaction between the reagents A and B to give the product P: A + B → P* → P + hν In practice, the reaction leads to the product …

the Experiment It is quite simple to prepare compounds that present the phosphorescence phenomenon. Starting from fluorescent organic molecules and inserting them into a glass matrix, the efficiency of non-radiative relaxation processes is greatly reduced. In practice, the molecule is trapped in a glassy or crystalline matrix and its mobility …

Introduction With the “phosphorimeter” described in the post Glowing in the Dark, we made a series of measurements on the classic zinc sulfide phosphorus, doped with silver and also with copper. Zinc sulphide is an interesting material : ZnS is a semiconductor, ie a material with an electron-filled valence band and …

Introduction Phosphorescence is the phenomenon of radiative emission by some materials/substances as a result of the absorption of energy through ultraviolet rays (very energetic) and the subsequent re-emission in the form of visible light (at lower energy). Phosphorescent materials continue to emit light up to many hours after the end …

Introduction A low-noise medium-high voltage generator is always of great use in the laboratory : it is used for the powering of photomultiplier tubes, geiger counters, ionization chambers, solid state sensors for radiation, etc …. However the construction of a component of this type is not simple : sometimes it is …

Introduction This post wants to examine with some detail the measurement of light intensity using the photon counting technique. We have already talked about it in other posts: Light as a Particle , Photon Counting. In this post we want to take particular care of the statistical distributions that are obtained …

Introduction In photometry of dim light sources (for example in the field of fluorescence) the “Photon Counting” technique is often used: this technique consists in the photon counting and the evaluation of the intensity of the light source in terms of the number of photons in the unit of time. …

In photometry with sensitive detectors such as SiPMs or photomultipliers it is important to have a light source of adjustable intensity but above all a light source of low intensity or even very low in order to avoid that the sensor goes into saturation or that it is even damaged. …

A bit of history: what is Trinitite ? The trinitite (also known as glass of Alamogordo or atomite) is the name given to the glassy residue formed in the desert, near Alamogordo in New Mexico, on the site of the explosion occurred on July 16, 1945, of the first nuclear …