Compare transmission and reflection gratings using detailed inputs. Review blaze alignment, losses, orders, and angles. Get fast estimates for smarter optical component selection today.
| Parameter | Example Value |
|---|---|
| Wavelength | 633 nm |
| Groove density | 1200 lines/mm |
| Order | 1 |
| Incidence angle | 20° |
| Diffraction angle | 28° |
| Blaze angle | 18° |
| Duty cycle | 0.50 |
| Substrate transmission | 92% |
| Coating reflectance | 88% |
| Surface scatter loss | 4% |
| Absorption loss | 3% |
| Shadow loss | 5% |
| Fill factor | 96% |
| TE share | 50% |
| Typical comparison goal | Choose the higher screening estimate |
This calculator uses a practical screening model for optics design work.
Groove spacing: d = 106 / G
Order ratio: r = mλ / d
Equation check: s = sin(α) + sin(β)
Mismatch: |r - s|
Alignment factor: exp(-((mismatch / 0.08)2))
Duty factor: [sin(πfm) / (πfm)]2
Order factor: 1 / (1 + 0.35(m - 1)2)
Geometry factor: √(cos α × cos β)
Polarization factor: weighted average of TE and TM response
Transmission estimate: 100 × common × substrate transmission × absorption factor × transmission blaze factor
Reflection estimate: 100 × common × coating reflectance × shadow factor × reflection blaze factor
This is an engineering estimate. It is not a full electromagnetic solver. Use RCWA or measured data for final procurement decisions.
Enter the operating wavelength in nanometers.
Enter groove density in lines per millimeter.
Select the diffraction order you want to compare.
Provide incidence, diffraction, and blaze angles in degrees.
Set duty cycle, fill factor, and TE share.
Enter material and loss values for the optical structure.
Click the calculate button to compare both grating types.
Review the efficiency values and the higher estimate.
Use the CSV button to export the result table.
Use the PDF button to save the page as a PDF.
Transmission and reflection gratings solve different optical design problems. This calculator helps compare both options with one consistent workflow. It is useful during concept studies, bench planning, and fast engineering checks. You can test wavelength, groove density, order, angle, and loss assumptions in seconds. That saves time before detailed simulation starts. The result section appears above the form after submission. This keeps the answer visible while you refine inputs.
The calculation combines grating spacing, order loading, angular alignment, blaze response, polarization weighting, aperture fill, and practical losses. Transmission efficiency depends strongly on substrate transmission and absorption. Reflection efficiency depends strongly on coating reflectance and groove shadowing. Both paths also lose performance from scatter and geometry mismatch. The model uses a scalar screening approach. It does not replace rigorous coupled wave analysis. Still, it gives a clean first estimate for engineering tradeoffs.
Transmission gratings are often attractive when compact layouts, straight optical paths, or lighter assemblies are needed. They can simplify some instrument geometries. They also work well when substrate transmission stays high at the target wavelength. In these cases, internal absorption stays low and the estimated transmission score can rise. This calculator lets you see that behavior quickly. Adjust blaze angle and diffraction angle together to inspect sensitivity.
Reflection gratings are common in spectrometers, monochromators, and laser systems. High reflectance coatings can improve throughput at specific bands. Reflection devices can also tolerate applications where substrate transmission is less attractive. Shadow loss and blaze mismatch still matter. That is why this page compares both estimates side by side. Use the example data table as a starting point. Then export results with CSV or save the page as PDF for design notes.
No. It is a screening calculator for fast engineering estimates. It combines geometry, blaze, polarization, and loss terms into a practical comparison. Use measured efficiency curves or RCWA tools for final design validation.
It means the model predicts a larger usable diffraction efficiency under the entered assumptions. The higher estimate can guide early design direction, but it does not guarantee better real hardware performance in every wavelength band.
The selected order performs best when the grating equation is closely satisfied. If the entered wavelength, groove density, and angles disagree, the alignment factor drops and both estimated efficiencies become lower.
Blaze angle pushes energy toward a preferred diffraction condition. When your operating geometry is close to the blaze condition, the related blaze factor rises. That often improves the estimated result for the chosen grating type.
Duty cycle describes how the groove profile period is divided. It affects the scalar diffraction term. Values near the wrong range for the selected order can reduce the model’s duty factor and lower the estimate.
Many optical systems carry mixed polarization. TE share lets you weight the response between TE and TM assumptions. This helps produce a more realistic screening estimate when polarization balance matters in your setup.
Transmission gratings often suit compact layouts, low absorption materials, and systems where forward propagation simplifies alignment. This calculator helps test whether those advantages overcome loss and blaze penalties in your case.
Reflection gratings often suit coated optics, spectrometers, and bands where reflectance stays strong. They can outperform transmission designs when coating quality is high and groove shadow loss remains controlled.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.