About BEP:
The Bidirectional Eigenmode Propagation method (BEP) is one of the modules OlympIOs currently offers for simulating the propagation of light through planar waveguide structures. The BEP algorithm approximates the total field as a superposition of forward and backward traveling (guided and radiation) modes of the structure, allowing for the calculation of reflections.

BEP benefits:
The BEP module is ideally suited to analyze waveguide structures that include large waveguide sections invariant in the propagation direction. In addition, the BEP module is well suited to calculating reflections that occur at various transitions in the planar waveguide circuit. Therefore, BEP is often used in the simulation and design of resonating structures. PML boundaries for the calculation window ensure that the radiating field will not reflect back into the calculation window and interfere with simulation results.
When performing vary-runs, our BEP module checks for redundant calculation parts and automatically re-uses previous results substantially reducing simulation time.
OlympIOs is the only commercially available platform that integrates the BEP method with the well known Beam Propagation Method (BPM) in a single user interface. The end-user can now simulate (parts of) the device using the fastest and most appropriate method.

Features:

• Includes guided and radiation modes
• Simulates reflections
• Perfectly Matched Layer (PML) boundary conditions
• Can handle high index contrast
• Can handle very wide propagation angles
• Avoids redundant calculations in vary runs

Generic simulation features:

• Extensive parameterization capabilities
• Vary runs
• Material library

Application examples
The following application notes demonstrates the use of our BEP module:

Simulation of a rectangular optical microresonator using bidirectional eigenmode propagation