Mode & Emission
The Mode page shows how emitted power is distributed across the optical loss channels of the device stack. The Emission page derives per-emitter radiative properties — Purcell Factor, effective Quantum Efficiency, and Lifetime — from the Mode detector results. Running the Mode detector is therefore a prerequisite for any data to appear in the Emission view.
Mode fractions
The Mode page decomposes total emitted power into 7 channels:
| Channel (UI label) | Abbreviation | Physical meaning |
|---|---|---|
| Top Outcoupling | TOC | Light exiting from the top into the environment medium |
| Bottom Outcoupling | BOC | Light exiting from the bottom into the environment medium |
| Substrate | SUB | Light confined in the substrate by total internal reflection at the substrate–air interface |
| Waveguide | WVG | Light trapped in the organic stack by total internal reflection and interference |
| Evanescent | EVA | Energy dissipated as evanescent waves, generally SPP loss |
| Absorption | ABS | Power absorbed on the TOC/SUB outcoupling paths |
| Non-radiative | NRA | Intrinsic non-radiative decay of the emitter (appears when Quantum Efficiency < 1) |
The k_in integration intervals defining each channel and the underlying derivations are covered in Emission Theory.
When the top surrounding medium is air, TOC equals the light extraction efficiency (LEE). When both Conversion Efficiency and Quantum Efficiency are 1 (their defaults), TOC = LEE = EQE.
Single / Weighted Average: donut chart
When the Wavelength Mode is Single or Weighted Average, the Mode page displays a donut chart showing the power fraction of all 7 channels at a single effective wavelength. The legend lists each channel name and its percentage.
Sweep mode: stacked area / line chart
When Wavelength Mode is Sweep, the x-axis becomes wavelength (nm) and the y-axis shows per-channel fraction. The default is a Stacked Area chart — the 7 channels sum to approximately 1 across the wavelength range, making it easy to see how each channel evolves with wavelength. Switch to the Line chart type to inspect individual channels without overlap.
Not-converged marker (*)
When one or more modes at a given wavelength fail to converge, the wavelength label is appended with *. A legend hint reads: * marks wavelengths with one or more modes that failed to converge.
Non-convergence typically occurs when the numerical tolerance is too loose or when the structure contains a very strong SPP resonance. Reduce the Tolerance value in the Mode detector configuration on the Optics page and re-run.
Sweep vs Weighted Average
In Sweep mode, the Mode page outputs a separate set of 7 channel fractions for each wavelength point, with the x-axis spanning the full wavelength range.
In Weighted Average mode, the wavelength dimension collapses to a single weighted value and the Mode page reverts to the donut chart display, behaving the same as Single mode.
Non-radiative channel (NRA): NRA appears only when the emitter's Quantum Efficiency is less than 1. Its fraction is not equal to 1 − q₀, because the Purcell effect changes the relative balance between radiative and non-radiative decay rates. The exact relationship is given in Emission Theory.
Emission (Purcell / effective QE)
The Emission view extracts the following per-emitter properties from the Mode detector results:
| Property (UI label) | Physical meaning |
|---|---|
| Purcell Factor | Enhancement factor F for spontaneous emission rate by the optical environment |
| Decay Rate Enhancement | Ratio of environment-modified to intrinsic total decay rate, b/b₀ |
| Quantum Eff. (Intrinsic) | Input intrinsic quantum efficiency q₀ (not affected by Purcell) |
| Quantum Eff. | Purcell-corrected effective quantum efficiency q_eff |
| Lifetime (Intrinsic) | Input intrinsic radiative lifetime τ₀ |
| Lifetime | Purcell-corrected effective lifetime τ |
Formulas for effective quantum efficiency and lifetime are given in Emission Theory.
Single / Weighted Average mode
When Wavelength Mode is Single or Weighted Average, each emitter is shown as a description card listing all properties (both intrinsic and effective values). There is no chart and no view toggle.
Sweep mode
When Wavelength Mode is Sweep (≥ 2 wavelength points), the page switches to chart/table mode. The right sidebar displays:
- Property: a RadioButton group to select Purcell Factor / Decay Rate Enhancement / Quantum Eff. / Lifetime
- Emitter: a dropdown showing all emitter names; selecting
All emittersplots one line per emitter
The x-axis is wavelength (nm); the y-axis is the selected property. The Purcell Factor typically shows a peak at wavelengths coinciding with microcavity resonances.
Controls
The common chart/table toggle and export controls (Export CSV, Export Image, Copy Image) are described in Basic Optical Results. Page-specific controls:
| Control | Function |
|---|---|
| Chart type selector | Stacked Area / Line (Mode sweep mode only) |
| Property (RadioButton) | Select which physical quantity to display in the Emission view (Sweep mode only) |
| Emitter selector | Select a single emitter or all emitters (Sweep mode only) |
If the page shows "No data", the most common causes are:
- no calculation has been run yet
- no layer is marked as emissive (enable the
Emis.toggle in the Structure page) - the Mode detector is not checked in the Emission detector lane of the Optics page (Emission view also depends on this)
Next
- Understand the k_in integration boundaries for each of the 7 channels, the Purcell factor derivation, and the effective QE formula: Emission Theory
- Observe how mode fractions and Purcell Factor change across a parameter sweep: Emission Sweep