We have demonstrated operation of a new photon momentum radiometer for measuring laser power levels above 1 kW by use of radiation pressure. The ‘axial’ design allows the input and output laser beams to remain collinear and the force sensing can be carried out with any analytical balance having a vertical sensing direction and sufficient readability (sensitivity). The design also provides for a parasitic fast photodiode power measurement that is calibrated in situ by the slower radiation pressure-based power measurement. This permits a short-time-constant measurement limited primarily by the photodiode bandwidth, rather than the response time of the force balance. Uncertainty contributions yield a relative expanded uncertainty of 2.1% for (1–2) kW and 1.2% above 2 kW (for laboratory environmental conditions). We perform a direct comparison between this new power meter and the existing primary standard radiation pressure power meter. We find the two techniques agree with an average inequivalence of 0.12% for continuous wave (CW) optical powers from (1–10.8) kW. This disagreement is well-explained by the quadrature-summed uncertainties of the two techniques.

我们已经演示了一种新的光子动量辐射计的运行情况，该光子动量辐射计用于通过辐射压力测量1 kW以上的激光功率。“轴向”设计允许输入和输出激光束保持共线，并且可以使用具有垂直感测方向和足够的可读性（灵敏度）的任何分析天平进行力感测。该设计还提供了寄生快速光电二极管功率测量，该测量可在现场进行校准通过较慢的辐射压力为基础的功率测量。这允许主要由光电二极管带宽而不是受力平衡的响应时间限制的短时恒定测量。不确定性因素产生的相对扩展不确定性为（1-2）kW为2.1％，高于2 kW为1.2％（针对实验室环境条件）。我们将这种新型功率计与现有的主要标准辐射压力功率计进行直接比较。我们发现，对于（1–10.8）kW的连续波（CW）光功率，这两种技术的平均不平等度为0.12％。两种技术的求和不确定性很好地解释了这种分歧。