Introduction In an earlier post, I used a sample of caesium chloride (CsCl) and a small Tesla coil to generate F centres. F centres are defects in the crystal lattice […]
Colour-Changing Crystals – An Update on F Centres Read More »
Introduction Here’s what happens when a highly fluorescent compound, in this case sodium fluorescein, dissolves in water and a UV lamp shines on the solution: https://youtu.be/A8RJeF3h6DQ The above video shows
What is Fluorescence Quenching? Read More »
In an earlier post, a popular but fairly basic version of the smartphone spectroscope was introduced. This was constructed from a sheet of thin card. A 20 dollar offering, available
The Smartphone Spectroscope – Upgraded Version Read More »
Introduction Here’s an inexpensive way to use the camera sensor in your smartphone as a light detector for a spectroscope. With a sheet of folded card and a cheap diffraction
Turn Your Smartphone into a Spectroscope Read More »
Introduction If you enjoy a gin & tonic in the evening after a hard day’s work, then you are consuming small amounts of the flavouring agent quinine. Look closely at
Quinine in Tonic Water Read More »
Introduction This post is to help the home experimenter identify the spectra of some common light sources that we all come across in the home. It gives us an indication
Common Light Sources in Your Home Read More »
Introduction One of the very first posts on this site introduced the basics of Absorption Spectroscopy and the concepts of Absorbance and Transmittance of light through homogeneous materials. In this
The Beer-Lambert Law and Spectrophotometric Analysis Read More »
Introduction Spectrum tubes are a very useful way to introduce science students to the study of the interaction of light photons with matter and the subject of optical spectroscopy. They
Introduction This post describes three simple demonstration spectrometers that the home experimenter can set up, with a minimum of optical elements, in order to get involved with examining spectra. These
Three Simple “Demo” Spectrometers Read More »
Introduction A thin film can be defined as any material with a thickness ranging from a fraction of a nanometre (nm) to a few microns (μm). The manufacture of thin
How Thin is a Thin Film? Introduction to Thin Film Reflectometry Read More »
Introduction Many spectral line profiles reported elsewhere on this blog frequently take advantage of a very versatile software package called Spectragryph. The software was developed as a successor to an
Introduction Here is the emission spectrum of hydrogen gas in a discharge tube recorded at moderate spectral resolution: Fig. 1 The Spectrum of Hydrogen Gas in a Discharge Tube It
The Hydrogen (and Deuterium) Emission Spectrum Read More »
Introduction In this post the emission spectra of the Noble Gases are presented. The noble gases constitute the last group (Group 18) in the Periodic Table of the elements. Emission
Emission Spectra of the Noble Gases Read More »
Introduction The above image is a sample of high purity caesium chloride crystals (CsCl). They are in a sealed glass ampoule and were prepared under high vacuum. At first glance,
Caesium Chloride and the F Centre Read More »
Introduction The chemical element Selenium. Atomic number 34. Chemical symbol Se. The quirky title I chose for this post – an element that can’t make up its mind – refers
Selenium: An element that can’t make up its mind Read More »
Introduction The humble Bunsen Burner has been a ubiquitous piece of lab equipment ever since it was invented by the German chemist Robert Bunsen in 1855. A testament to its
The Bunsen Burner, the Swan Bands and the Dicarbon Enigma Read More »
In a previous post I described one of the “workhorses” I have been using for several years for recording spectra. This is the Oriel MS125 spectrometer coupled with an InstaSpec
Freedom from DOS at Last! Read More »
Introduction In a previous post, the phosphorescent properties of several glow-in-the-dark decorative paints were evaluated. The active phosphor in these paints was likely to be europium-doped strontium aluminate. In this
Eu-Doped Strontium Aluminate Phosphorescence Read More »
Introduction There are a number of technical constraints to consider when selecting a spectrometer for a particular application, whether this involves purchasing a commercial model from the wide range of
Factors Affecting Spectrometer Performance Read More »
Introduction An off-axis guider is a device well known to all astronomers, professionals and amateurs alike. It usually consists of a compact optical unit inserted between the main imaging camera
Off-Axis Guiders and Sighting Optics Read More »
This is a quick post that examines the spectral line emission changes that occur when a Mercury-Argon (Hg-Ar) gas discharge lamp is switched on and warms up. I used the
Mercury Lamp Spectral Changes at Start Up Read More »
The calibration of spectra in wavelength λ that you will see in these different posts has usually been performed with commercial “pencil-type” spectral lamps of mercury-argon Hg(Ar), krypton (Kr) and
Light Sources for Calibrating Spectrometers Read More »
Introduction Modern spectrometers today, regardless of their size, employ sensitive linear CCD and CMOS sensors. The most popular sizes have 1024, 2048 and more recently 4096 pixels along the dispersion
Spectrometer Calibration Read More »
Introduction The development of the spectroscope over the last 160 years since its invention has paralleled the evolution in technological advances. This is particularly the case over the last several
Spectrometer Designs Read More »
Introduction As its name implies, this spectrometer has a fixed diffraction grating. So the wavelength range available and the resolving power (the spectral resolution) are pre-determined during manufacture. Oriel (now
FICS -Fixed Imaging Compact Spectrograph Read More »
Absorbance In very general terms, Absorption Spectroscopy is the spectroscopic technique that considers what happens when electromagnetic radiation of any wavelength passes through a material and some of these
Absorption Spectroscopy Read More »
