Production of Light Flashcards
What is the cause of light production in a laser?
Electron transitions in atoms in a gas due to stimulated emission.
What are the features of laser light?
It’s coherent, polarised & monochromatic.
What is the valence band?
The highest filled band of energy for electrons in an atom.
What is the conduction band?
The lowest unfilled band of energy for electrons in an atom.
In this band, electrons can easily move from one atom to the next, hence conducting electricity.
What are p-type semiconductors?
Semiconductors with spare ‘holes’ in the valence band.
What are n-type semiconductors?
Semiconductors have spare electrons in the conduction band.
What is the cause of light production in LEDs?
Electron transition in semiconducting material from conduction band to valence band.
What are features of LED light?
Can be monochromatic, but isn’t polarised or coherent.
What is the cause of light production from a synchrotron?
Acceleration (deflection) of charged particles (electrons) due to magnetic fields.
What are the features of synchrotron light?
Wide range of wavelengths, polarised, very intense (can be coherent)
What is the cause of light production of incandescent light?
Acceleration of charged particles due to thermal vibrations.
What are the features of incandescent light?
Continuous spectrum, but isn’t polarised, coherent or monochromatic.
