Supercontinuum Characterisation

Photonic crystal fibre based supercontinuum light sources, combining the brightness of lasers with the broad bandwidth of incandescent lamps, are a promising candidate for sources in spectroscopic applications.

A Bentham TMc300 triple grating monochromator was used to provide calibrated measurements of photonic crystal fibre based supercontinuum light sources from 320nm to 2600nm. Correct spectroradiometric calibration is essential to avoid the many systematic artefacts occurring over this broad spectral range.

Fully automated grating and detector selection as well as automated slit adjustment for constant bandwidth gives simple operation over this broad spectral range. The sensitivity of the detection system allows the use of an integrating sphere at the input, which permits measurement without regard to the variation of spatial output between different fibres.

Different monochromator configurations are available for the measurement of super continuum sources up to, and beyond 5µm. A double monochromator configuration gives the ability to measure bright narrow laser lines without scattering background, and to measure the weak ultraviolet components of a supercontinuum in the presence of broad band very bright light (multi-Watt laser power).