Multiple noncritical phase-matchings in biaxial KTP crystal

• Main Authors: Zadorozhnii, V.I., Kornienko, M.E., Sidenko, T.S.
• Format: Article
• Language: English
• Published: НТК «Інститут монокристалів» НАН України 2006
• Series: Functional Materials
• Online Access: http://dspace.nbuv.gov.ua/handle/123456789/139960

А general approach is developed and conditions of noncritical phase matchings (РМ) of different multiplicity for the sum frequency generation process are analyzed taking a biaxial КТР crystal as an example. The approach is based on the consideration of general properties of a РМ surface constructed in the frequency and angle coordinates, analysis of their singular lines and intersection points of those lines. The lines of non-criticality in signal frequency or in the propagation angles of the interacting waves have been consid- ered on the РМ surface. The classification of double-uncritical (in frequency and one of the angles or in two angles) РМs is proposed. The possibility to realize a triple non-criti- cality in three independent quantities, for example, frequency and two angles, has been shown. It is found that the double non-criticality (in frequency and IR signal divergence) region can be scanned over the whole transparency range of КТР under frequency tuning of the long-wavelength laser pumping. Мultiple non-critical РМs allow visualizing the broadband IR spectra and IR images.