Modeling of polarization effects in Fourier domain mode-locked (FDML) lasers

• Applicant: Professor Dr.-Ing. Christian Jirauschek
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: from 2013 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 243341030

The goal of this project is to model polarization effects in Fourier domain mode locked (FDML) fiber cavity laser systems. These lasers generate fast frequency sweeps over a wide spectral range, as needed for various medical imaging and sensing applications. Our proposal is motivated by experimental evidence that the polarization dynamics can greatly affect the output power and coherence properties. Furthermore, FDML sources with controlled polarization properties are required for polarization dependent applications. One example is polarization sensitive optical coherence tomography, yielding depth-resolved information on polarization changing properties of human tissue, which can be helpful for diagnostics. In detail, the theoretical description of FDML operation, developed in our DFG project, will be extended to include the polarization dynamics, and an efficient simulation algorithm based on the split-step Fourier method will be implemented. This will enable a realistic modeling of non-polarization maintaining FDML laser setups, predominantly used in practical applications. Additionally, residual polarization effects in polarization maintaining FDML laser designs, employing polarization maintaining optical components for polarization control, can be analyzed. A central goal is to develop an improved understanding of FDML polarization dynamics and its influence on laser operation especially in non-polarization maintaining lasers. Furthermore, our simulations aim at an application-specific optimization of FDML operation, for example with respect to output power, coherence or polarization properties.

• DFG Programme: Research Grants