Learning Forum

[arezoo.tahmasebi]

Hello colleagues, 
I have a question about detector view in Zemax. Once you've got the detector view after the ray tracing, you can go to the settings for the detector view window to change how the data is shown, including things like incoherent irradiance, coherent irradiance, radiant intensity, coherent phase and so on. I'm more interested in how the light energy is distributed over the detector plane and also the exact geometry(outline) of the output beam. I'm trying to simulate a design where I can get a rectangular or square beam geometry (beam outline) on the detector, with the energy distributed evenly across the whole rectangular or square beam profile. I was just wondering which type of show data would tell me about how the energy is distributed on the detector. I've attached two screenshots of my design, where I switch from incoherent irradiance to radiant intensity. By the way, I alread  checked the zemax help.

Regards
Arezoo

[Elham Sarbazi]

Hi Arezoo,

Thanks for reaching out to us!

Incoherent Irradiance is the power per area, so it is a function of spatial position on the detector with units Watts/area (e.g, Watts/cm2 as in your screenshot). Radiant Intensity is the power per solid angle, so it is a function of ray’s incident angle upon the detector, with unit Watts/steradians.

If you need to check the distributed power on the detector then coherent/incoherent irradiance metrics seems more relevant. Note that, when computing the incoherent irradiance, OpticStudio adds up the power of each ray that strikes the same pixel without considering the phase of the rays. On the other hand, when obtaining the coherent irradiance, OpticStudio sums the complex amplitude of each ray that strikes the same pixel, keeping track of the real and imaginary parts separately considering the phase of each ray.

You can find these details at the link below (section “Discussion”).
Detector Viewer

Please also refer to section “Comments on coherent data computations” at Detector Rectangle Object  to check the assumptions made by OpticStudio when calculating the coherent irradiance.