Cascaded Arrayed Waveguide Gratings for High Resolution Integrated Photonic Spectrographs

We arenbsp;proposing to develop an integrated photonic chip for implementing a cascadednbsp;arrayed waveguide gratings (AWG) spectrometers on a Si3N4/SiO2 platform for use in the detection of exoplanets based on Precision Radial Velocity (PRV) method.nbsp;In Phase I of this proposal, an integrated high spectral resolving power (R~150,000), high throughput (~25%) AWG spectrometer with multiple fiber inputs for simultaneous calibration on a Si3N4/SiO2 platform is proposed, which will be followed by a Phase II proposal for designing a flat focal field AWG spectrometer, with the focal signals of all wavelengths of operation focusing along a straight line, and for designing a polarization insensitive AWG for measuring the optical spectra of the star and the planet.nbsp;Integration on a chip reduces the size, the weight, the cost, and increases the stability of astronomical spectrographs.nbsp;An external calibration sources, like Optical Frequency Combs (OFCs), can be coupled to the AWG spectrometers through the additional fiber inputs to provide the broad spectral coverage and long-term (years) stability needed for extreme PRV detection of exoplanets.