| Pulse duration | 1 picosecond (ps) = 10−12 seconds; 1 nanosecond (ns) = 1,000 ps. “Picosecond” describes pulse duration, not overall treatment quality. | Request the measured pulse duration at the treatment handpiece, the measurement method, and whether the specification is a nominal value or a tested range. Ask how pulse duration is defined, such as full width at half maximum (FWHM). |
| Wavelength options | Commonly encountered options include 1064 nm and 532 nm; 532 nm is the frequency-doubled wavelength of 1064 nm. Some systems also offer wavelengths around 730–755 nm, depending on the laser design. | Match wavelengths to the intended indication, operator training, and applicable labeling. Confirm that each wavelength is available at the stated output and spot sizes; wavelength alone does not establish suitability or results. |
| Pulse energy | Usually stated in millijoules (mJ) per pulse. Pulse energy and fluence are different measurements: energy is the amount delivered in a pulse, while fluence is energy per unit area. | Compare energy at the handpiece—not only inside the laser—and check the available energy at each wavelength, spot size, and repetition rate. Ask for calibration and measurement uncertainty information. |
| Fluence | Fluence is commonly expressed in J/cm². For a uniform beam, fluence = pulse energy ÷ illuminated area. For non-uniform or Gaussian beams, the stated value depends on the measurement and beam-area convention. | Request the calculation method, beam profile, and usable fluence range for each spot size. There is no single fluence value that is appropriate for every indication, skin type, or treatment protocol. |
| Repetition rate and average power | Repetition rate is measured in hertz (Hz), or pulses per second. At a constant pulse energy, average optical power is pulse energy (J) × repetition rate (Hz). | Check whether maximum pulse energy is maintained at the highest stated repetition rate. Ask about thermal management, output stability, and any duty-cycle limits during extended operation. |
| Spot size and beam profile | Spot size is generally reported in millimetres (mm). Changing spot size changes the illuminated area and therefore affects fluence for a given pulse energy. | Verify spot-size options, measurement tolerance, beam uniformity, and output across the usable treatment area. Ask whether the reported spot size refers to the aperture, the skin plane, or another defined measurement plane. |
| Output stability | Stability can be reported as variation in pulse energy or output over a stated number of pulses and operating period. A commonly used statistical description is coefficient of variation (CV) = standard deviation ÷ mean. | Request test conditions, sample size, warm-up requirements, and results at representative settings. Compare like-for-like measurements; a stability claim without test conditions is difficult to assess. |
| Cooling and operating duty | Cooling design and permitted duty cycle affect practical operating continuity and maintenance needs. These depend on the system design and room conditions; there is no single universal cooling benchmark. | Check the specified ambient temperature and humidity range, cooling method, maintenance schedule, and performance limits during prolonged use. Confirm local service and replacement-part availability. |
| Electrical safety | IEC 60601-1 is a general standard for basic safety and essential performance of medical electrical equipment. Applicability depends on the product and its intended use. | Request applicable test reports or conformity documentation for the exact device configuration. Confirm that power, grounding, and plug requirements match the destination market. |
| Electromagnetic compatibility (EMC) | IEC 60601-1-2 addresses electromagnetic disturbances for medical electrical equipment and systems. | Check the applicable EMC documentation and any installation requirements, especially where the device will operate near other medical or wireless equipment. |
| Laser classification and user protection | IEC 60825-1 covers the safety of laser products, including classification and related labeling requirements. High-powered treatment lasers require appropriate controls and trained users. | Verify the device’s laser classification, labels, key control, interlocks, emergency stop, protective eyewear specifications, and user training materials. Eyewear must be suitable for the emitted wavelengths and optical density requirements. |
| Quality management documentation | ISO 13485 specifies requirements for a medical-device quality management system. It is not, by itself, proof that an individual device meets every performance or regulatory requirement. | Check the certificate scope, validity, and issuing body, and separately review device-specific technical and regulatory documentation. |
| Market authorization and labeling | Requirements vary by country and intended use. CE marking, where applicable, relates to relevant EU requirements; U.S. FDA pathways and status depend on the device and its intended use. | Verify the exact model, intended use, authorized claims, importer obligations, and required local registrations or approvals in every destination market. Do not treat one market’s documentation as automatic approval elsewhere. |
| Serviceability and total cost | Purchase price alone does not capture operating cost. Training, maintenance, consumables, shipping, downtime, and local service can affect lifetime cost. | Compare warranty terms, response times, technician coverage, spare-part lead times, preventive maintenance, and training provisions in writing. |