Estimate pulse energy from power, duration, or fluence. Choose practical units for optics labs, classrooms. Export clean results to CSV, PDF, and reports anytime.
| Method | Inputs | Computed Pulse Energy | Notes |
|---|---|---|---|
| Average power | 2 W, 1 kHz | 2 mJ | Energy = Pavg/f |
| Peak power | 50 kW, 20 ns | 1 mJ | Energy = Ppeak·τ |
| Fluence | 0.5 J/cm², 2 mm diameter | ≈ 15.7 mJ | Energy = F·A, A = π(d/2)² |
E = Pavg / fE = Ppeak · τE = F · A, where A = π(d/2)² for a circular spotPulse energy is the joules in one shot. It influences microscopy excitation, ranging return strength, and processing thresholds. It also lets you compare sources fairly when repetition rate and pulse width are different.
With an average-power reading, use E = Pavg/f. Example: 2 W at 1 kHz equals 2 mJ per pulse. Selecting kHz instead of Hz changes the result by 1,000.
When peak power and duration are known, apply E = Ppeak·τ. A 50 kW pulse lasting 20 ns gives 1 mJ. Non-rectangular pulses can shift the true peak power.
Fluence (J/cm²) is energy per area, so E = F·A. The calculator can compute area from diameter using A = π(d/2)². Because area scales with d², measure beam size carefully at the target plane.
Q-switched sources often deliver 0.1–500 mJ from ~10 Hz to kHz. Mode-locked systems may run near tens of MHz with nanojoule pulses, yet high peak power from femtosecond durations. Fiber systems commonly sit between.
Use computed fluence to compare against optic and sensor limits. If margins are small, reduce energy, expand the beam, or add attenuation. Start alignment at low settings, then step upward while watching scatter and heating.
Optional repetition rate enables average-power reporting, and optional duration enables peak-power and intensity estimates. These are planning numbers, not replacements for calibrated measurements. Note assumptions such as beam shape, measurement plane, and transmission losses.
Use CSV for spreadsheets and PDF for logs. Record the method, units, and where energy was measured (source, after optics, or target). Consistent reporting prevents unit mistakes and improves repeatability.
If you know average power and repetition rate, use E = Pavg/f. It is the most common measurement workflow because many meters report average power directly. Ensure the repetition rate is correct.
Energy formulas are exact, but peak power depends on pulse shape. The calculator uses a simple E/τ estimate for peak power, which corresponds to a flat-top approximation. Use an oscilloscope or autocorrelator for detailed profiles.
Area depends on the square of the diameter. A 10% diameter error creates about a 21% area change, which directly affects fluence and intensity. Measure beam size carefully at the target plane.
Use beam area when the spot is elliptical, clipped, or measured by imaging. A direct area value avoids circular assumptions and improves fluence and intensity estimates, especially for shaped beams and apertured systems.
Yes. Select appropriate time units such as fs and provide pulse energy. The tool can estimate peak power and intensity, but note that ultrafast systems may require dispersion and temporal-shape considerations for precision.
Provide pulse energy and repetition rate. The calculator reports average power using Pavg = E·f. This is useful when an energy meter is available but a power meter is not.
Intensity is power per area, so SI units are W/m². It is helpful for comparing to nonlinear thresholds and damage limits. You can convert to W/cm² by dividing the W/m² value by 10,000.
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.