She invented, developed, and applied the X-ray scanning tool for quality control essential to manufacturing indium gallium arsenide phosphide-based multi-quantum well lasers.
She worked for 4 years (1964–1968) at Royal Dutch Shell laboratory in Amsterdam, where she joined the research group on catalytic properties of transition metal-layered chalcogenides.
In 1986 Vandenberg turned her attention to the quality control of the crystal growth of InGaAsP multi-quantum well (MQW) layers, used as laser light sources and optical modulators designed to work in the 1.3 to 1.55 μm wavelength range.
To insure that these multiple failure modes do not impact the final device, Vandenberg designed a one-room (later bench-top) non-destructive high-resolution X-ray diffractometer[JAP87][JAP89] to provide immediate on-line feedback into the MQW growth process.
She constructed robust algorithms linking X-ray features to layer thickness and strain information essential to crystal growth control and optoelectronic device performance.
Vandenberg received the 1995 and 1997 Optoelectronics Award in recognition of contributions to the development of characterization and process control routines for manufacture of Lucent's world class semiconductor lasers.