(c) Dr Paul Kinsler. [Acknowledgements & Feedback]
This is part of an information maze -- see the index-file for the full picture.
"Optical" means "of light". An optical-cavity is made by getting two mirrors and facing them towards each other. With the mirrors perfectly parallel to each other, the light will bounce back and forth between the two -- so this is often called a cavity because it is like a box ("cavity") where you can trap light.
By using curved mirrors, the light can be stopped from travelling sideways and escaping. If the mirrors are high quality, this trapped light finds it hard to escape and can become very intense. In addition the confined light has a small range of wavelengths and these two effects are important in allowing us to make lasers.
A microcavity is a small optical-cavity, only about a micrometre (1 millionth of a metre) long. This is so small that only a few wavelengths of visible or infra-red light can fit between the mirrors, and so the light is in quantum-confinement. Microcavities can be made of semiconductor material, but these usually do not have sideways confinment.
XINDEX: polariton, light, index-file.
19990610 19961128 12 19951107 1024 0815 (c) Paul Kinsler
XKEYWORD: optical-cavity
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