Experimental and Theoretical Investigations of Two-Photon and Free Carrier Absorption in a GaAs/A1GaAs Quantum Well Waveguide,
Abstract
There have been many studies of two-photon absorption (TPA) in semiconductors. In calculating the TPA coefficient, beta, the effect of free carrier absorption (FCA) has often been neglected. However, it is relatively straightforward to include this by means of an intuitive theoretical model. The model's use can be demonstrated in evaluating B from nonlinear absorption experiments carried out in GaAs/AlGaAs Multiple Quantum Well (MQW) waveguides using a Nd:YAG laser. When only linear absorption and TPA are considered and the experimental analysis carried out in the usual way, the TPA coefficient B is calculated to be 2.2xl0-10 m W-1 for TM polarisation, and 2.7xl0-l0 m W-1 for TE polarisation. Including the effect of free carrier absorption in the waveguide, the model predicts B to be 1.5x 10-10 m W- 1 and 2.0x 10-10 m W-1 for TM and TE polarisations respectively.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1992
- Accession Number
- ADP008117
Entities
People
- F. R. Laughton
- J. H. Marsh
- J. S. Roberts
Organizations
- University of Glasgow