Learning Forum

[Kenny Chen]

Hello,

I am simulating the propagation of light in a silicon waveguide along the x-axis at a wavelength of 1550nm. My goal is to calculate the remaining power of light after propagating a certain distance.

I have placed a DFT monitor at x = 100 um (with the light starting at x=0), but I am unsure about which properties (E, P, T) should be choose for the monitor.

Additionally, would the monitor type "Linear X" be suitable for calculating the light energy distribution along the propagation axis (x-axis)?

Thank you.

[Devika Padmakumar Nair]

Hello, You like to calculate tranmission after a particular length right?

While analyzing the result using DFT monitor, keep this in mind. 

E: Electric field data as a function of position and frequency/wavelength.
H: Magnetic field data as a function of position and frequency/wavelength.
P: Poynting vector as a function of position and frequency/wavelength.
T: Transmission as a function of frequency/wavelength.

You can get more information here :Frequency-domain Profile and Power monitor - Simulation object – Ansys Optics

I would suggest to use "2D X-normal" monitor type. 

Thanks

[Kenny Chen]

Thank you for your response.

I have placed 2D-X normal DFT monitors at x=0 and x=100. However, I'm unsure about the appropriate size for these monitors.

For instance, the dimensions of the waveguide are 400nm x 220 nm, and I intend to simulate light propagation at 1550 nm (even a broadband light source).

Could you please advise on the suitable size for the light source (mode source) and the monitors?

Should the light source be larger than the waveguide to ensure full injection of light into the waveguide?

Also, I wonder if the monitors should be larger than the waveguide to capture the entire light distribution around the waveguide boundary?

Thanks.

[Devika Padmakumar Nair]

 

Hello,

In the geometry tab, make sure the monitor is centered and set the x span and y span to match the span of the simulation region.

Please see the video to understand more about mode sources:

Optical Sources – Mode Source – Introduction & Applications – Ansys Optics

Optical Sources – Mode Source – Setup & Tips – Ansys Optics

Monitors: 

Monitors – Introduction and Common Settings – Ansys Optics

Monitors – Frequency-Domain Field – Results & Applications – Ansys Optics

Monitors – Frequency-Domain Field – Setup & Tips – Ansys Optics

And yes, the monitors should be larger than the waveguide to capture the entire light distribution around the waveguide boundary.

I would also recommend the following course : Ansys Lumerical FDTD – ANSYS Innovation Courses

Thnak you