Measure performance across diffraction orders with quick inputs. Compare raw and corrected efficiency for experiments. Download CSV reports and print clean PDF result sheets.
| Case | Incident Power (mW) | Diffracted Power (mW) | Wavelength (nm) | Groove Density | Order | Raw Efficiency (%) |
|---|---|---|---|---|---|---|
| Green Laser Test | 10.0 | 3.8 | 532 | 1200 | 1 | 38.00 |
| Red Laser Test | 8.5 | 2.9 | 650 | 600 | 1 | 34.12 |
| UV Order Check | 12.0 | 4.4 | 405 | 1800 | 1 | 36.67 |
Primary efficiency formula: η = (Pd / Pi) × 100
Here, Pd is diffracted power in the selected order, and Pi is the incident optical power.
Corrected efficiency formula: ηc = [(Pd × C) / (Pi × (1 - L/100))] × 100
C is detector correction as a decimal factor. L is the pre-grating loss percentage.
Grating equation: mλ = d sin θ
m is diffraction order, λ is wavelength, d is groove spacing, and θ is diffraction angle.
Groove spacing: d = 1,000,000 / N
N is groove density in lines per millimeter, and d is shown in nanometers.
Diffraction grating efficiency tells you how much incident optical power is redirected into a chosen diffraction order. This value matters in spectroscopy, laser routing, wavelength selection, and optical bench testing. A higher efficiency means more useful light reaches the detector, fiber, or imaging path. This calculator helps you estimate raw and corrected efficiency from measured powers. It also checks groove spacing, diffraction angle, and illuminated width coverage. That makes it useful for quick lab evaluation and practical comparison between gratings.
A diffraction grating never sends all light into one order. Some energy stays in the zero order. Some goes to higher orders. Some is lost through absorption, scatter, coating limits, or alignment errors. Because of that, efficiency becomes a key performance metric. Engineers use it to compare reflective and transmissive gratings. Researchers use it to verify setup quality. Students use it to connect measured power with diffraction theory. When efficiency drops, signal quality can fall and exposure time can rise.
Incident power is the optical power reaching the grating system. Diffracted power is the measured output in one selected order. Wavelength and groove density determine the angular response through the grating equation. Diffraction order identifies which beam you are studying. Pre-grating loss accounts for upstream attenuation. Detector correction adjusts readings when your sensor calibration requires scaling. Grating width and illuminated width show how much of the grating face is being used during the measurement.
Raw efficiency is the direct power ratio. Corrected efficiency includes detector and loss adjustments. Groove spacing helps confirm the geometry of the grating. The angle result shows whether the selected order is physically possible for the entered wavelength and line density. If the corrected value exceeds one hundred percent, the input data should be checked. Use the example table, formula section, and export tools to document your optical tests with a clean and repeatable workflow.
It is the percentage of incident optical power directed into a selected diffraction order. It helps you judge how effectively the grating sends light where your system needs it.
Raw efficiency uses the measured power ratio only. Corrected efficiency also includes detector scaling and upstream loss, so it better reflects the actual optical performance of the grating setup.
Yes, but that usually signals inconsistent measurements, incorrect detector correction, or inaccurate loss assumptions. In normal conditions, a physically realistic result should stay at or below 100%.
Each order sends light in a different direction and often with different intensity. Measuring the correct order is essential when you compare gratings or align an optical system.
The chosen wavelength, groove density, and order combination does not satisfy the grating equation. In that case, the selected order cannot propagate as a real diffracted beam.
Yes. Both power values should use the same unit, such as milliwatts. The efficiency ratio stays valid because the unit cancels during calculation.
Those inputs show how much of the grating surface the beam covers. They help you understand beam usage and whether the illuminated region exceeds the available ruled width.
No. Higher groove density changes diffraction angle and can improve performance for some wavelengths, but it may reduce efficiency in other conditions. The best choice depends on wavelength, order, coating, and blaze design.