Emitter Setup

This guide explains how to mark an emissive layer in Structure and set an Emitter spectrum, position, orientation, and efficiency. Afterward, you can create a usable light source for an emission simulation.

Marking an emissive layer

In the Structure page layer table, every Layer row has an Emis. column (header Emis.). Click the toggle switch in that column to mark the layer as an emissive layer (EML).

Toggle-on behavior

• If the layer's emitter list is empty, the system automatically seeds one default emitter (named Emitter 1) and expands the emitter editor for that layer.
• The emitter editor appears as an expansion row beneath the layer; click the EML pill in the layer type column to collapse or expand it.

Toggle-off behavior (non-destructive)

• Turning off the Emis. switch does not delete existing emitter data; the editor collapses but data is preserved.
• Re-enabling the switch restores the full emitter list.

Multi-EML support

Multiple layers can be marked as EML simultaneously. Each layer holds its own independent emitter list.

Layer Group-nested layers

Layers inside a Layer Group also support the Emis. toggle. The Optics page inspects both top-level and group-nested layers to determine whether any emissive layer (EML) is active.

Emitter editor

The emitter editor displays all emitter cards for the selected layer. Each card header provides an enable/disable toggle, move up, move down, duplicate, and delete controls; the card body is a 4-column grid containing all fields below.

Gaussian Spectrum Generation

When only the peak wavelength, full width at half maximum (FWHM), and an approximate lineshape are available, you can synthesize a normalized Gaussian spectrum in the emitter editor without preparing a two-column spectrum file. One component provides an idealized narrowband or broadband starting point; several components can approximate shoulders, broad envelopes, and multipeak emission.

Set Spectrum Type to File, then click Generate in the Spectrum File row. The generator keeps the Gaussian components, wavelength range, and live preview in one dialog:

1. Select a parameter preset as a starting point, or edit the components directly. Peak, FWHM, and Weight must each be greater than 0, and at least one component must remain.
2. Use Add component to add peaks. Weight is the relative amplitude before combination and normalization; the global maximum of the final spectrum is normalized to 1.
3. Set From, To, and Step. Clicking Auto-fit Range once reads the wavelength settings of all enabled detectors and fills their combined range. If no usable range exists, Dreapex TMM estimates a range that covers the tails of the current Gaussian components.
4. Check the live preview and click Apply. The generated data is written to the current emitter; afterward, use the preview button at the right of the spectrum row to inspect it, add a description, or export the data.

Auto-fit Range updates the values only when clicked. Editing a component afterward does not recalculate the range, and manual range edits remain in place for the current application.

Choose the spectrum unit

Probability denotes a photon-number spectrum and is appropriate for most photon-counted PL / EL measurements. Power denotes a radiant-power spectrum and should be used only for spectra calibrated as power. The two descriptions are related by the photon energy:

Here, $E_\gamma(\lambda)$ is the energy of one photon at wavelength $\lambda$, $h$ is the Planck constant, and $c$ is the speed of light in vacuum. $\Lambda_N(\lambda)$ is the photon-number spectral density, while $\Lambda_P(\lambda)$ is the radiant-power spectral density. Because shorter-wavelength photons carry more energy, the same vertical-axis values declared as Probability and Power represent different physical spectra.

Unit White means constant only in the selected unit. Unit White + Probability is flat in photon number; Unit White + Power is flat in radiant power and gives progressively greater photon-number weight to longer wavelengths.

Dipole distribution

The Distribution field sets the spatial profile of emitting dipoles across the layer thickness.

Click the preview button next to the Distribution dropdown to open a dialog showing the sampled distribution curve under the current parameters.

The distribution is sampled inside the layer and renormalized so the total integral equals 1; absolute amplitude is governed by Multiplication Factor and Conversion Efficiency independently of the profile shape.

Conversion Efficiency is the probability that recombining charges form emitting excitons. For one emitter, it scales Intensity and Power Dissipation linearly but does not change the relative Mode composition. With several emitters, different conversion efficiencies also change their relative weights in the combined Mode, spectrum, and color.

Validation

Next

After configuring emissive layers and their emitters, go to Emission Detectors to select which emission detectors to run (Power Dissipation, Intensity, Mode) and configure their wavelength ranges.