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 In Part 2 of this article on the development of the infrared spectrometer, I covered the basic details of the Fourier transform version of the instrument – the FTIR.
The Infrared Spectrometer – Part 3 Read More »
Introduction In Part 1 of this article we looked at the development of the dispersive infrared (IR) spectrometer employing a grating monochromator and slits. And the details of some sample
The Infrared Spectrometer – Part 2 Read More »
Introduction Quite a few articles on this site have looked at atomic and molecular spectra in the UV and visible regions of the electromagnetic spectrum, in emission, absorption and even
The Infrared Spectrometer – Part 1 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 »
Happy Halloween! Halloween is fast approaching 👻 so why don’t you try out this fun experiment with your kids? The next time you’re out in the woods, collect a few
Spooky Horse Chestnut Fluorescence! 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 In two earlier posts on this site we recorded the absorption spectrum of molecular iodine I2 with some simple instrumentation. The first section outlined the basic theory giving rise
The Fluorescence Spectrum of Iodine Read More »
Introduction In part 1 we covered the construction of the SAM III boards, the connections between the boards and incorporated the boards into a suitable box. In this post we
The SAM III Magnetometer – Part 2 Read More »
Introduction In several previous posts the physical principles describing the fluxgate magnetometer were introduced. We went on to construct a simple magnetometer based on a single fluxgate sensor, available from
The SAM III Magnetometer – Part 1 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
Uploading the Data to a Website If you have been following so far, at this point we should have the Raspberry Pi set up, configured, and the necessary program modules
Aurora Monitor – Part 4 Read More »
Introduction Well, it has taken me a few months to get around to finishing this particular project, but here are the final sections that I have split into two parts.
Aurora Monitor – Part 3 Read More »
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 »
This post will be fairly short since I’m away from the “home lab” and relaxing in Thailand. I’m staying at a place called The Sanctuary on Phangan Island (Koh Pha-ngan),
A Quick Blog Post from Paradise 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 Mention the words “chemistry set” to anyone who grew up in the 1950’s and 60’s, and watch their reaction. If they had an interest in science as a child,
Chemistry Sets of Today and Yesterday Read More »
Introduction This is the second part of a project to build an Arduino-controlled constant temperature enclosure. In the first part of the project we set up the Arduino microcontroller to
Arduino-Controlled Temperature Enclosure – Part 2 Read More »
Introduction In previous posts the fluxgate magnetometer was described. The frequency pulses from the fluxgate sensor were captured by an Arduino microcontroller then sent to a Raspberry Pi for further
Arduino-Controlled Temperature Enclosure – Part 1 Read More »
Introduction In Part 1 of this 4-part post, the fluxgate magnetometer (FGM) was introduced. We outlined how this device can be used to detect changes in the Earth’s geomagnetic field
Homemade Aurora Monitor – Part 2 Read More »
Introduction Magnetometers are instruments used to measure magnetic fields. They have been around in different forms since the great physicist and mathematician Karl Friedrich Gauss devised the first one almost
Homemade Aurora Monitor – Part 1 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 In a previous post we described the Raman Effect and provided a non-mathematical introduction to some of the basic principles of Raman spectroscopy. The final sections of that particular
Introducing the Thunder Optics Raman Probe 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 Part I of this post I briefly described some of the properties of the iodine molecule. The position of iodine in the Periodic Table and its electron configuration
The Iodine Absorption Spectrum – Part 2 Read More »
Introduction Iodine. Atomic number 53. Chemical symbol I. Iodine is the rarest of the stable halogens, if we ignore the radioactive elements Astatine (At) and the recently discovered (in 2010)
The Iodine Absorption Spectrum – Part 1 Read More »
Introduction Over the years I have gradually accumulated a collection of optical filters. Some of these date back to the days of silver halide photography and are the well-known Kodak
Optical Filter Transmission Spectra 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 The Raspberry Pi is a Single Board Computer (SBC) that has an enormous following online with schoolteachers, hobbyists and for many industrial applications. It was first introduced by the
The Raspberry Pi Shake & Boom Read More »
Introduction Does anyone remember having glow-in-the-dark stars, planets and constellation stickers that as kids we would stick to our bedroom walls and ceiling? I don’t think I am the only
Phosphorescent Paints Read More »
Introduction An optical table, or bench, is the optical equivalent of the very popular solderless prototyping breadboards that many electronics hobbyists regularly use to test and develop their electronic circuits.
A Homemade Optical Table Read More »
Many years ago, shortly after I obtained my PhD in physical chemistry, I moved from the UK to go and live in France. Basically I had met a French girl
Who Discovered What and When? A slightly amusing historical tale… 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 »
Measuring the fluorescence from highlighter pens is always an interesting educational experiment to try and is very popular in schools and colleges to demonstrate the basic principles of fluorescence and spectra. Usually, green, blue or violet laser pointers are used to excite the sample.
Highlighter Pen Fluorescence Read More »
I’ll say it again: Raman rules! No apologies because I’m a big fan of his. So who on earth am I talking about? I am referring to the Indian physicist
In a previous post we described in scientific terms the basic principles of the optical phenomenon of reflection. The definition of the percentage reflectance of light from the surface of
Fruit and Veg Spectroscopy! 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 »
Introduction MS125 This is a very versatile spectrograph that I have used over the years to record a variety of spectra from various emission sources, astronomical objects and other samples.
MS125 and InstaSpec IV Combination Read More »
Introduction This post describes some construction details for an improved version of the SGS spectrometer in what I called the MFSS or Multiple Fixed Slit Spectrograph. The design was intended
Homemade Spectrometers (Part II) Read More »
A few years ago I built a couple of diffraction grating spectrographs. At that time I was a keen amateur astronomer with some degree of traditional photographic, as well as
Homemade Spectrometers (Part I) Read More »
Introduction Several years ago I connected the MS125 spectrometer to a 12 inch Meade LX200 telescope to test its suitability for recording stellar spectra. In order manually to guide on
Some Early Stellar Spectra Read More »
Reflection is simply the return of a light ray from any surface without any change in wavelength. It is also referred to as Reflectance, defined as the effectiveness of any
Diffuse Reflectance Spectroscopy Read More »
What is Fluorescence? Before we can consider what fluorescence actually is in scientific terms, we must mention the general process of luminescence. Luminescence is defined as any emission of light
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 »
