White Light Interferometer | SIMTRUM Photonics Store

Our White Light Interferometer GOBI uses spectrally resolved interferometry to accurately measure the Group Delay Dispersion (GDD) of multi-layered ultrafast optics. The device has been developed at the MaxPlanck-Institute of Quantum Optics (Garching, Germany) to characterize and refine some of the most advanced coatings to date [1-3]. Combining spectral with temporal information and the possibility to accumulate multiple passes over the same optic ensures reliable results with unique spectral coverage of up to 250-1060 nm (UV/VIS/NIR version) and 900-2400 nm (IR version). 

Spectrally resolved detection makes reference lasers together with any related test sample restrictions on specific reflection or transmission bands obsolete. This opens the full spectral range to characterize even ultra-broadband or advanced narrowband coatings. The flexible optical setup can measure mirrors and transparent samples under angles of incidence variable between 0 and 70 degrees.

In contrast to other devices GOBI is able to resolve strong GDD oscillations. Note that differences between measured and theoretical curves reflect tolerances in the manufacturing process of the coatings.

Examples of GDD measurements with our White Light Interferometer GOBI, and comparison to the theoretical design. 

(a) Ultrabroadband PC70 mirrors with our unique doubleangle design, measured at 5° and 19° angle of normal incidence, together with the average. 

(b) Pulse Compression Mirror PC1921 for the infrared.

(c) High dispersive HD73 mirror with -3000 fs2 per bounce at 1030 nm.