In the cutback measurement, the fiber is rewound in loops in 1 m diameter. Ando AQ6315A and Ocean spectrometer USB4000 are used to measure the transmitted power before and after cut at visible and UV wavelengths respectively.

The measurement of 266 nm laser transmitted through hollow-core fiber is by using power meter to directly measure the laser power at the output of fiber. Recording the reading usually takes a few seconds and the average of minimum and maximum power during this period of time is recognized as the transmitted power.

The fluorescence is measured by using a short piece of multimode (approx. 15cm) fiber to sample light into Ocean spectrometer.