Application Gallery

 Grating order transmission

This example provides example simulations which use the grating order transmission analysis group to calculate the fraction of power transmitted into each grating order.  It also shows how to calculate the number of grating orders that exist as a function of wavelength. The grating order transmission analysis group is available from the object library.

FDTD

Associated files

grating_order_transmission.fsp

grating_order_transmission.lsf

BFAST

Grating examples

Grating projection toolbox

Grating and far field projection analysis objects

grating, find, pinch script commands Simulation setup

Calculating the total transmitted power through a monitor is very easy to do with the transmission function.  However, it is sometimes necessary to calculate the power scattered into a particular grating order of a periodic structure.  This calculation is more challenging, requiring both the grating and transmission functions, plus a reasonable amount of matrix manipulation.  The analysis object also calculates the number of supported grating orders.

The associated simulation files use the grating order transmission analysis object to do these calculations. You can insert this object from the object library in the far field projections section.

Results

To reproduce these results, open grating_order_transmission.fsp, then run grating_order_transmission.lsf. The script will run the simulation, then run the analysis object scripts and create some final plots, as shown below. Note that we used BFAST  source so all the interested wavelengths have the same incident angle.

Figures created by the analysis objects:

 Transmission monitor Reflection monitor Number of supported grating orders   Notice that the -Z direction (reflection) supports more orders. This is due to the higher index of the substrate. Also notice that more grating orders are supported at shorter wavelengths.  Total transmission through the monitor, and the transmission to the (0,0) grating order.     Notice that when there is only one supported grating order, T_(total) is equal to T_(0,0)  Propagation direction of the (0,0) grating order, in terms of theta, phi.  The propagation direction and strength of the grating orders at 0.8um.  Figures created by the script grating_order_transmission.lsf.

 Number of supported grating orders in both reflection and transmission. Total reflection and transmission, and the reflection and transmission into the (0,0) grating order. Copyright Lumerical Inc. | Privacy | Site Map