By Vvon Engineering Team | Published
Match a laser power meter or energy sensor to wavelength, CW or pulsed operation, beam size, damage limits and console compatibility before requesting a quotation.
Choose the sensor before choosing the display. A console can show a stable number while the connected head is unsuitable for the wavelength, pulse energy or beam diameter. For a useful quotation, describe the light reaching the sensor and the measurement you need, including whether you need average power, energy per pulse or a time-resolved waveform.
Power is energy per unit time, expressed in watts. Pulse energy is the energy in an individual pulse, expressed in joules. For a stable train of equal pulses, average power equals pulse energy multiplied by repetition rate. An average-power reading alone does not reveal pulse-to-pulse variation or the temporal shape of each pulse.
As a calculation example, 1 mJ pulses at 1 kHz give 1 W average power. That does not make them equivalent to a 1 W continuous beam for sensor damage or detector saturation. Pulse duration and beam area are still needed. Estimating peak power by energy divided by pulse duration also depends on the pulse-shape and duration definition.
| Sensor family | Measurement to consider | Key selection limits |
|---|---|---|
| Photodiode power sensor | Power of a suitable narrowband source within the detector range | Wavelength response, saturation, active area and permitted peak loading |
| Thermal power sensor | Average power over an appropriate spectral and power range | Absorber coating, response time, cooling and power/energy density |
| Pyroelectric energy sensor | Energy of individual compatible light pulses | Minimum/maximum pulse energy, pulse duration, repetition rate and damage limit |
Thorlabs’ power-meter interface and sensor guide explains the different sensor signals and the need to apply the correct wavelength responsivity. Start in Vvon’s photodetectors and beam-diagnostics category, then compare a named sensor model rather than only the family heading.
The catalogue groups C-Series photodiode power sensors, C-Series thermal power sensors and ES-Series pyroelectric energy sensors. Each family contains different ranges and apertures. The final offer should identify the exact head, any attenuator or adapter and its calibration.
A beam can fit through the entrance aperture but exceed the absorber’s permitted local loading. Check total power, power density, pulse energy and pulse-energy density under the wavelength and pulse conditions stated in the datasheet. A sensor rated for the average power may still be unsuitable for a short, intense pulse.
If attenuation or a beam sampler is required, specify its wavelength, angle, polarisation and power limits and include its measured transmission or splitting ratio in the result. Keep the beam safely terminated. Do not use an unverified attenuation factor to protect the head or report the original beam power.
The PM100D2/PM100D3 handheld consoles and PM5020 dual-channel console serve different readout and acquisition requirements. Confirm that the chosen head and measurement mode are supported by the exact console and firmware. Matching the connector alone is insufficient.
For two-channel transmission or stability measurements, define whether channels must be sampled together and how the ratio is calculated. For pulsed work, confirm the maximum supported event rate and whether the software records each pulse or averaged values. Thorlabs’ Optical Power Monitor manual documents mode-specific operation; software display and export rates should not be assumed equal to the optical detector’s response speed.
Ask for the head and readout calibration information, applicable wavelength/range, stated uncertainty and any correction factors. Include repeatability, background subtraction, alignment, attenuation and temperature effects in the measurement procedure. Recalibration and intermediate checks should reflect use, drift history and the consequences of an incorrect result. Our calibration and traceability guide explains what to review in the record.
Send the application, wavelength/spectrum, CW or pulsed parameters, beam diameter/profile, minimum and maximum expected reading, required uncertainty, free-space or fibre geometry, logging needs and any existing head or console model. Include a source datasheet where available and describe whether the setup is for teaching, research, alignment checks or production measurements.
Share your application, equipment requirements and procurement timeline. Our engineers can help clarify the configuration and scope for your enquiry.