Numerous applications in medical technology require more than just knowing the overall power or energy of a laser beam. Many more parameters play a role, such as power distribution, power density or focal shift. Measurement is performed by camera-based technologies using conventional CCD or CMOS cameras that are intelligently combined with optical components and powerful software. Here, too, the measurements show clear differences in quality, in terms of both absolute measurement results and reproducibility. In addition to the type of camera chosen by the instrument’s manufacturer, the software algorithms and optical components implemented exert a major influence on this.
A high-quality, camera-based measuring instrument even allows the measurement of tunable lasers, which can be adjusted from UV to IR – and still delivers reliable results. This, in turn, results in direct cost savings for the user, as only one measurement setup is needed for wide spectral ranges. The camera resolution should also be taken into account: If a laser system requires special beam shaping, the manufacturer must know the energy distribution within the beam. For example, if a homogeneous energy distribution in the laser beam is required for an application in, say, dermatology, the camera resolution must be correspondingly high. Otherwise, the power peaks are simply not displayed.
Measuring laser beams in medical applications is beyond question: It is absolutely essential to measure power, energy and/or beam profile along the entire value chain, starting with the laser source manufacturer through to the end user of the laser system, whether in medical production or patient settings. It is certainly worth one’s time to be very exacting when selecting a measuring instrument. Quantitative criteria must be taken into account, including the power and energy range to be measured, the aperture size in relation to the beam size and the operating temperature of the sensor. However, qualitative aspects must also be considered, as they can impact the quality of the end product and/or the success of the therapy on the patient. If one tries to save money on the quality of the measuring devices, this can either mean forfeiting any optimization potential or require a significantly higher effort in terms of time and cost to achieve the same laser beam quality.