Micromachined Fourier transform spectrometer on silicon optical bench platform

We present a miniaturized Fourier transform spectrometer implemented on a silicon optical bench platform. Both optical and opto-mechanical components of a Michelson interferometer, including a silicon beam splitter, micromirrors, MEMS actuators, and fiber U-grooves, are simultaneously fabricated by micromachining of the device layer of a silicon-on-insulator wafer. Our specialized bulk micromachining process combines the flexible definition capability of deep reactive ion etching with the good surface quality provided by anisotropic KOH wet etching. This integrated Fourier transform spectrometer has a measured spectral resolution of approximately 45 nm near 1500 nm wavelength.