DIRECT MEASUREMENT OF THE REFRACTIVE-INDEX CHANGE OF SILICON WITH OPTICALLY INJECTED CARRIERS

Silicon phase modulators are important silicon optoelectronic devices. The relationship of the refractive index change with injected carrier concentration is the basis for the operation of silicon phase modulat ors. No direct experimental data of this relationship have been report ed, We have developed a new method for the direct measurement of this relationship using a Fabry-Perot interference and optical injection of carriers. The experimental results of the refractive index change are reported for the first time in the range of injected carrier concentr ation between 10(13) and 10(15) cm(-3). It should be noted that our ex periment results are about 5 to 10 times larger than those predicted b y theory. The reliability of our experiments is also discussed. (C) 19 96 American Institute of Physics.