Optical nonlinear device with a quantum - heterostructure.

摘要

PURPOSE:To generate a higher harmonic with a high efficiency by embedding a semiconductor or an insulator of a direct transition type being different from a parent body a size of the same degree as an exciton. CONSTITUTION:A parent body semiconductor 1 and an embedded semiconductor 2 are laminated alternately several times, and constitute as a whole a quantum well structure (QWS) being one of quantum microhetero structures (QMHS). Also, since a bias electric field is applied to the QWS 3 by a power source 50, the potential is inclined as a whole. Accordingly, the potential to an electron and a hole is asymmetrical, and as for these wave functions 81, 82, the center-of- gravity positions are different from each other. As a result, an exciton comes to have a large dipole moment. When a fundamental wave 10 of an angular frequency omega which is emitted from a light source such as a semiconductor laser 4, etc. passes through the inside of this QWS 3, a part thereof is converted to a higher harmonic 12 of an angular frequency 2omega. In such a case, the conversion efficiency becomes extremely high since it is proportional to a square of non-linear susceptibility chi(2).