Investigation of Nonlinear Optical Properties of Semiconductors
Author | : D. G. Seiler |
Publisher | : |
Total Pages | : 137 |
Release | : 1984 |
ISBN-10 | : OCLC:227609430 |
ISBN-13 | : |
Rating | : 4/5 (30 Downloads) |
Book excerpt: Nonlinear optics is an increasingly interesting and exciting area of physics. Many nonlinear optical effects have been discovered and various nonlinear optical devices constructed from a wide variety of materials. In particular, small band gap semiconductors like InSb can have unique optical properties because of their small effective masses and direct band gaps. Unusual and often unexpected results are found in their nonlinear behavior--optical bistability, nonlinear refraction, laser pulse limiting and shaping effects, optical transistor action, etc. These effects can be described in terms of a third order susceptibility and are associated with the creation of free carriers by the light. The creation of even a small number of free electrons or holes can strongly effect the 'dynamic' nonlinear optical properties of the material. In this project we used sensitive photoelectronic methods to investigate the nonlinear generation of electrons in InSb, CdS, and GaAs induced by two-photon absorption of light. A wide variety of photoelectronic effects are initiated by the creation of free carriers from the absorption of light in a semiconductor or insulator. These include the photo-Hall effect, photoconductivity, recombination, trapping, lifetimes, all of which are important for understanding devices such as light detectors, light emitters, or energy converters.