Wafer-level packaging of three-dimensional MOEMS device with lens diaphragm

This paper presents wafer level packaging of a miniature MOEMS monochromator for biomedical spectroscopy. Optical microlens and piezoelectrically-actuated diffraction grating are fabricated, and packaged at a wafer level into a complete, integrated monochromator with a fiber input. The packaged monochromator is an optical and mechanical system derived from a macroscale Czerny Turner monochromator. It integrates an angled mirror for folding and directing the input light path. A lithographically-defined reflective diffraction grating accepts and spectrally separates the input light from a fiber that is inserted into the built-in groove. The diffracted light is then collected through a diaphragm-suspended microlens and spatially separated on its path towards the output of the system. The packaging, done via encapsulated silicon cavities, provides batch processing and finishing of the complete device. The MLD is characterized with a Gaussian beam propagation model and the SSC packaged device is measured by its resolution and stray light through profiling with a CCD array.