An ultra compact spectrometer based on the optical transmission through a micro interferometer array

We present a chip-level integrated optical spectrometer and demonstrate its high resolution performance by using finite-difference time-domain (FDTD) simulations. In this miniature interferometer-based spectrometer, a two-dimensional array of micron-scale phase objects made from polymethyl methacrylate (PMMA) is mounted on an imaging device. Our analysis shows that the two-dimensional intensity distribution obtained by the imaging device can be described by a system of simultaneous linear equations when the phase delay within each interferometer element is pre-designed appropriately. One can readily recover the spectral contents of the input radiation with picometer resolution. The proposed design takes advantage of the well-established imaging integrated circuits and precision molding technologies for producing miniature, low-cost and high performance optical spectrometers, which may find applications in a wide range of applications.