Multilayered MOEMS Tunable Spectrometer for Fluorescence Lifetime Detection

Spectral and time-domain fluorescence from biological samples are powerful diagnostic tools. For applications requiring a compact integrated spectrometer, the microoptoelectromechanical system (MOEMS) is an enabling technology. To improve upon previous microspectrometers, a multilayered, folded design is taken here to improve theoretical resolution and throughput. This sub-cm³ prototype, based on MOEMS piezoelectric diffractive micrograting, demonstrates over 100-nm tuning in the visible range. Moreover, it integrates a microlens with f = 2.2 mm within a microoptics package that is fabricated at wafer-level. The microspectrometer capably records both spectral and lifetime information for fluorescence standards fluorescein isothiocyanate (FITC, 2.5 ns) and Rhodamine B (2.9 ns), and also Collagen Type II (2.4 ns).