Long-range parametric amplification of THz wave with absorption loss exceeding parametric gainстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 19 июля 2013 г.
Аннотация:Optical parametric mixing is a popular scheme to generate an
idler wave at THz frequencies, although the THz wave is often absorbing in
the nonlinear optical material. It is widely suggested that the useful material
length for co-directional parametric mixing with strong THz-wave
absorption is comparable to the THz-wave absorption length in the material.
Here we show that, even in the limit of the absorption loss exceeding
parametric gain, the THz idler wave can grows monotonically from optical
parametric amplification over a much longer distance in a nonlinear optical
material until pump depletion. The coherent production of the nonabsorbing
signal wave can assist the growth of the highly absorbing idler
wave. We also show that, for the case of an equal input pump and signal in
difference frequency generation, the quick saturation of the THz idler wave
predicted from a much simplified and yet popular plane-wave model fails
when fast diffraction of the THz wave from the co-propagating optical
mixing waves is considered.