The Light Side of Science

Nice old optical technique

2010-08-24T09:30:00.000+01:00

Traditional black and white photography uses chemicals that are sensitive to light, particularly silver halides. As they are sensitive to a broad range of wavelengths covering the visible, they will react under any light, and so cannot distinguish between them. Colour photos (not digital photos) work by having different layers that are sensitive to different wavelengths, red green and blue, and

Cool flexible OLED display

2010-07-21T11:09:00.001+01:00

Ok, so it has been a while since the last post. This is very interesting though; Samsung are on the verge of releasing a new plastic OLED display. The electronics of course will be on a different board, but the entirity of the screen itself is made of plastics thin films and organic materials and is very flexible. It's so flexible in fact that you can smack it with a hammer and it won't break...

The European Extremely Large Telescope; Adaptive Optics and Resolution Power

2010-04-27T16:29:00.002+01:00

Europe has recently announced the construction of the world's largest optical telescope the imaginatively named European Extremely Large Telescope (E-ELT).... and it is extremely large - though not as large as the proposed Overwhelmingly Large Telescope, that was scaled down to this project. The primary mirror (main mirror that collects the light) will be 42m across. Using current technology, it

Quickfire Question: How do Fiber Optics work?

2010-04-27T14:58:00.000+01:00

When you stick something in water - something like a pencil or a ruler is best since they are straight, you can see the object appear to bend at the surface of water. This is due to the differences in refractive index between the water and the air. All materials have a refractive index, because of the way that they interact with light. The vacuum, free space, has a refractive index "n" of 1,

Light and the Age of the Universe: George Gamow

2010-04-16T16:03:00.000+01:00

In my discussions on the Cosmic Microwave background, I realised I had made a horrible omission: a guy called George Gamow. While I do not wish to take any of the well deserved credit from the winners of the Nobel Prizes, Gamow was one of those names who was sadly lost in history. He had actually predicted the CMB, or something like it, back in 1948. Here is a nice little article about it. http:

Quickfire Question: How do LEDs work?

2010-04-13T13:47:00.002+01:00

LEDs, or Light Emitting Diodes are very common devices used in a wide variety of applications from some street signage, power indicators, transmitters in remote controls and even LED torches. They are very efficient devices, which much like sodium lamps, convert most of the current passing through them into light, with very little loss as heat, but how do they work? All LEDs are made from

Basic Optics: The principles of imaging - lenses and pinholes

2010-04-12T21:39:00.001+01:00

We are all familiar with imaging - everything we see results from the imaging of the world on to our retina. Cameras image the world onto a film or a CCD, usually through a lens. Projectors display images on a screen, but how and why does imaging work. If we imagine the light either bouncing, or being emitted from an object. That light passes through a hole, and then on to a screen. How do we

Light and the Age of the Universe - The Discovery and Analysis of the CMB

2010-03-03T12:35:00.017Z

Discovery of the Cosmic Microwave BackgroundThe Comic Microwave Background was discovered pretty much by accident by Arno Penzias and Robert Wilson who were working for Bell Laboratories, looking for signals from radio waves reflected from balloons. In the course of their experiments, they had to eliminate all noise sources such as radio broadcasts, and even a "white dielectric substance" left on

Light and the Age of the Universe - the Cosmic Microwave Background

2010-03-03T11:46:00.012Z

Our main window to understanding the universe is light and the electromagnetic spectrum. Trapped here on earth, there is very little of the universe that we can actually touch and test with our own hands, but light provides an amazing tool. The Cosmic Microwave Background is perhaps on of the best methods we have of finding the age of the universe.All objects that are in thermal equilibrium -

Quickfire Question: How do incandescent (filament) bulbs work?

2010-03-01T14:18:00.011Z

We are all familiar with incandescent bulbs, which have been until relatively recently been the most popular sort of bulb.A voltage is placed across a metal filament held in an inert gas like argon, neon or nitrogen, in order to stop the gas from reacting with the filament and allowing the bulb to live longer. The filament has a high resistance to the current flowing through it, and this heats

Quickfire Question: Why are street lamps amber?

2010-02-28T08:16:00.010Z

We are familiar with the colour of many street lamps, the amber glow of the sodium vapour:But how do these lamps work, why are they the colour that they are, and why do we use them?(1) How do Sodium Lamps WorkInside the tube, there is a small amount of sodium metal, with a little neon and argon gas in there. A voltage is applied across the tube, and this excites the outer electrons in the neon

The Science of Optics: Polarization of light, Water, Insects and 3D Cinema.

2010-02-27T17:46:00.037Z

As mentioned earlier, light is a transverse wave, but as it is in 3D space (rather than on a surface like water) it can oscillate in any direction perpendicular to the direction of motion. The particular polarization depends on the relationship between the electric and magnetic field, but the simplest polarization is linear polarization - the light oscillates in a flat plane. When interacting

Optics and Life: Strange Sight - The world in Ultra Violet

2010-02-27T11:01:00.009Z

We are all familiar with rainbows, showing us the full spectrum of colour that we can see- red, orange, yellow, green, blue, indogo and violet, but the electromagnetic spectrum continues beyond both sides of the rainbow. Red is the longer wavelength (around 600nm), and longer we have infra-red (which is pretty much responsible for the radiated heat you feel from a fire or the Sun), microwaves and

Lasers

2010-02-10T10:47:00.004Z

We are all pretty familiar with lasers these days, from laser pens to the sorts of lasers that evil masterminds use to cut British Secret agents in half (an example here being James Bond and Goldfinger), but what are they exactly?Laser is actually an acronym, and it stands for Light Amplification by Stimulated Emission of Radiation. let's go through the terms. Light... well we know about that.

The Science of Optics: What is a Photon?

2010-02-09T13:44:00.001Z

Once scientists started developing a better understanding of how light works - how it propagates and its effects. One of the biggest mysteries has been - what is it exactly? Is it a wave? Is it a particle? It turns out that it is in some ways neither, and in some ways both, and now I will explain why we know this.The Wavelike properties of lightThe wavelike properties of light are just like water

The Ancient History of Optics

2010-01-15T17:41:00.000Z

People have puzzled and pondered over how we see for many thousands of years, though a more complete understanding of optics was not truly available to us until more recent centuries through the work of scientists like Newton, Young, Maxwell and Dirac. Some of the earliest known writings on optics date back to the Ancient Greeks. The majority of the earliest ideas on optics were largely

Let there be Light

2010-01-15T17:16:00.000Z

Hi and thanks for taking a look at my blog. I'm an optical physicist, having studied optics for several years from a lowly undergraduate and Masters student at Imperial College London, before completing a PhD in Organic LED technology, and now working in Biomedical Sensors. The aim of this blog is going to be a combination of updates of the latest news in optics covering a wide variety of areas (