Archive by category | Celebrating the Day of Light

Spreading the love of light

Spreading the love of light

If you have been following this blog for the last few weeks you will already know that some of us at Nature Research really love the science of everything light and its applications. But we didn’t want to stop at talking about different wavelength ranges on the internet, we also wanted to go out there and talk to people directly; and this being the International Day of Light (IDL), we didn’t limit our outreach events to only one country either.  Read more

Radio frequencies: The many lives of radio waves

Radio frequencies: The many lives of radio waves

The radio frequency (rf) range is one of the most technologically exploited portions of the electro-magnetic spectrum. Although the definition is not strict, the rf spectrum commonly refers to waves with frequencies between 20 kHz and 300 GHz. This also includes microwaves, which have frequencies stretching from 300 MHz to 300 GHz. Rf technology was discovered in the early days of modern physics, and it quickly became the cornerstone of mass media broadcasting. Unlike optical signals at higher frequencies, rf waves are generated with electronic circuits comprising a capacitor and an inductor. In these so-called LC circuits, electronic charge carriers can be made to oscillate and, as a consequence, emit electromagnetic radiation at the desired frequency. The faster the oscillation and the smaller the corresponding circuit, the higher the frequency of the emitted waves; amplitude and frequency modulation of the produced waves enables the encoding of information.  Read more

Terahertz: Entering applications

Terahertz: Entering applications

The electromagnetic spectrum spans a rich range of wavelengths – from short-wavelength, highly energetic x-rays at one end through to long-wavelength radiowaves at the other. While many regions of this spectrum have already been explored by mankind and put to good use there is one that is still largely underexploited – that of terahertz waves. Lying in the region between infrared light and microwaves, terahertz waves (photons with a frequency between ~300 GHz and 10 THz), fall into a gap between the worlds of photonics and electronics. However, in recent years scientists have been increasingly exploring how such terahertz waves can be exploited. Historically, difficulties in efficiently generating and manipulating terahertz waves served as a barrier for the area. However, several developments have changed the fortunes of the field.  Read more

Mid-Infrared: the molecular fingerprint region

Mid-Infrared: the molecular fingerprint region

Mid-infrared (mid-IR) radiation – typically defined as 2.5–10 µm wavelengths (although the exact values can vary) – is not something many of us come across in our daily lives. We can’t see it and we don’t use it for data transmission either. So, why do we care about it at all? Well, mid-infrared radiation can help us identify many materials by their characteristic spectra.  Read more

Visible spectrum: On our wavelength

Visible spectrum: On our wavelength

The Earth’s Sun emits a tremendous amount of electromagnetic radiation in the Earth’s direction. Even though the entire spectrum of light is incident on this planet, why is it that we humans only see in a tiny band that we have — rather appropriately — named the visible spectrum?  Read more

Ultraviolet radiation: Not just for a suntan

Ultraviolet radiation: Not just for a suntan

Ultraviolet (UV) radiation identifies the region of the electromagnetic spectrum where wavelengths are longer than those of X-rays. The extreme UV (XUV) range identifies light with a wavelength around 10 nm and up to 100 nm; far-UV and middle-UV regions are characterised by wavelengths between about 100 nm and 200 nm and between 200 nm and 300 nm, respectively. Near-UV radiation extends to around 400 nm, which is commonly taken as the lower value for visible wavelengths. You may wonder – why should one bother to label these intervals so diligently? While the precise boundaries of these ranges are not set in stone, the UV region peculiarly spans two different orders of magnitude in wavelength (or, equivalently, in frequency): the fastidious labels for each sub-region are there to remind us that the features and applications of light in the longer-wavelength near-UV region are distinct from those characterising short-wavelength XUV radiation, for example.  Read more

X-rays : a tale of bones, molecules and mummies

X-rays : a tale of bones, molecules and mummies

X-rays are the portion of the electromagnetic spectrum that falls between gamma rays and the ultraviolet (UV) — their wavelength is of the order 0.01−10 nanometres. What’s fascinating about them is their extremely wide range of applications, going from astronomy to art.  Read more

Interactions: John Dudley on the International Day of Light

Interactions: John Dudley on the International Day of Light

Last year, UNESCO proclaimed the International Day of Light – or IDL for short – as an annual celebration of the role of light and light-based technologies in society. The first ever IDL is happening soon, on 16th May, and on your wavelength will join in the celebration with a series of light-related blog posts spread across the whole month of May.  Read more