Everything about Optical Rectification totally explained
Electro-optic rectification (EOR) (also referred to as optical rectification) is a
non-linear optical process which consists in the generation of a DC
polarization in a non-linear medium at the passage of an intense optical beam. For typical intensities, optical rectification is a second order phenomenon (difference frequency mixing) which is based on the inverse process of the
electro-optic effect. It was reported for the first time in 1962, when radiation from a
ruby laser was transmitted through potassium dihydrogen phosphate (KDP) and potassium dideuterium phosphate (KD
dP) crystals.
Optical rectification can be intuitively explained in terms of the symmetry properties of the non-linear medium: in the presence of a preferred internal direction, the polarization won't reverse its sign at the same time of the driving field. If the latter is represented by a sinusoidal wave, then an average DC polarization will be generated. This is the analogue of the
electric rectification effect, where an AC signal is converted ("rectified") to DC.
When the applied electric field is delivered by a
femtosecond laser, the spectral bandwidth associated with such short pulses is very large. The mixing of different frequency components produces a beating polarization, which results in the emission of electromagnetic waves in the
terahertz region. The EOR effect is somewhat similar to a classical electrodynamic emission of radiation by an accelerating/decelerating charge, except that here the charges are in a bound dipole form and the THz generation depends on the second order susceptibility of the nonlinear optical medium.
Together with carrier acceleration in semiconductors and polymers, optical rectification is one of the main mechanisms for the generation of terahertz radiation using lasers. This is different from other processes of terahertz generation such as
polaritonics where a polar
lattice vibration is thought to generate the
terahertz radiation.
Further Information
Get more info on 'Optical Rectification'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://optical_rectification.totallyexplained.com">Optical rectification Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |