High resolution spectrographs with spectral resolution R = λ/∆λ > 5,000 are one of the most important tools for nearly every discipline in astronomy, but the design of high resolution spectrographs have not experienced significant changes in last several decades. A conventional high resolution spectrograph usually contains a collimator, echelle grating, cross disperser, and finally a camera and science detector—both typically semiconductor detectors. Here we propose developing a spectrometer where the light is separated and channelized by a photonic circuit and is then detected by an energy-resolving superconducting detector. The instrument would be a radical new type of high resolution spectrograph applicable for both multiobject and integral field unit (IFU) spectroscopy and other fiber fed light applications. Our goal is to create a high resolution multi-object spectrograph by marrying two breakthrough technologies, ultra-low loss arrayed waveguide gratings (AWG) and Microwave Kinetic Inductance Detectors, or MKIDs. MKIDs can determine the energy of each arriving photon without read noise or dark current, and with high temporal resolution. The AWG allows us to disperse light from the telescope, in a compact way and to position the dispersed light into numerous output channels which we can conveniently position (i.e. dispersed not just by the angle at which it diffracts off a prism or grating). The MKID allows us to distinguish between the orders in the disperse light contained within the channels, eliminated the need for a cross-disperser. In other words, the energy resolution of the MKID allows us to determine from which echelle order the photon came.
The most promising application for the High Resolution Photonic MKIDS Spectrograph is for High Dispersion Coronagraphy (HDC) for the detection and characterization of exoplanets. Having many fibers in a high-resolution spectrograph instead of one allows HDC to go from being a follow-up technique only to an incredibly powerful tool for both detection and characterization. Another science application is looking at resolved stellar populations with adaptive optics across the local group but increasing the observational efficiency by 100×.
The development of broadband high-resolution visible wavelengths spectrometers finds increasing applications in the life sciences and medical field, including spectral tissue sensing and optical coherence tomography. In addition, the PICs developed in this program operating at cryogenic temperatures can also be fundamental building blocks for quantum computing and communications.