October/November 2009

FEATURE

Why photonics research is vital

Most people are happy with the improvements that modern life offers us every day. Driving a car becomes ever easier and safer thanks to improved supporting systems. GPS systems are getting more and more ‘intelligent’ in order to help us avoid traffic jams. Personal computers are becoming more and more versatile and convenient due to improved processor performance. This list could be endless and could give us the impression that the current state-of-the-art is brilliant – and that we don’t need any further improvements.

FEATURE

Safety first

Human eyes are remarkable organs, capable of a dynamic range of around 1,000,000:1, allowing us to tread carefully on star-lit nights, or see our way to an oasis in the brightest desert. Our eyes are well adapted to seeing visible light at wavelengths from 380-750nm, as these colours are abundant in nature. Nature, however, presents no light sources as intense as modern lasers. Even at relatively low powers, laser radiation can cause permanent damage to the retina of the eye, and it can do so whether the wavelength emitted is visible or not.

FEATURE

Lithography lessons

The semiconductor industry has grown from its origins in the 1960s to the multi billion dollar industry of today, with silicon chips found virtually everywhere in modern society. The birth of the integrated circuit (IC) – a miniature electronic circuit made up of a number of transistors integrated onto a semiconductor substrate – revolutionised the electronics industry and since then, improvements in fabrication methods have allowed smaller chips to be made incorporating greater numbers of transistors.

FEATURE

Super sensitive

When a piece of metal absorbs light of a frequency above a certain threshold value, (corresponding to UV wavelengths for most metals), it gains a charge, as some of its electrons are removed. This is called the photoelectric effect, and after it was first described mathematically by Einstein in 1905, it went on to form the basis of our understanding of the way in which light contains quanta of energy – what we now call photons.

FEATURE

The diode specialist

During an economic period when companies that have grown too quickly and too broadly are falling by the wayside, it’s refreshing to find a company that has stuck to its guns, and ploughed a successful furrow in one particular niche of photonics. Dilas describes itself as ‘the laser diode company’. It’s an accurate description, because laser diodes are all it does. Other photonics companies produce laser diodes, of course, but mostly as an offshoot of the main business of lasers.