Status of the Keck Planet Imager and Characterizer phase II development

Abstract

The Keck Planet Imager and Characterizer comprises of a series of upgrades to the Keck II adaptive optics system and instrument suite to improve the direct imaging and high resolution spectroscopy capabilities of the facility instruments NIRC2 and NIRSPEC, respectively. Phase I of KPIC includes a NIR pyramid wavefront sensor and a Fiber Injection Unit (FIU) to feed NIRSPEC with a single mode fiber, which have already been installed and are currently undergoing commissioning. KPIC will enable High Dispersion Coronagraphy (HDC) of directly imaged exoplanets for the first time, providing potentially improved detection significance and spectral characterization capabilities compared to direct imaging. In favorable cases, Doppler imaging, spin measurements, and molecule mapping are also possible. This science goal drives the development of phase II of KPIC, which is scheduled to be deployed in early 2020. Phase II optimizes the system throughput and contrast using a variety of additional submodules, including a 952 element deformable mirror, phase induced amplitude apodization lenses, an atmospheric dispersion compensator, multiple coronagraphs, a Zernike wavefront sensor, and multiple science ports. A testbed is being built in the Exoplanet Technology Lab at Caltech to characterize and test the design of each of these submodules before KPIC phase II is deployed to Keck. This paper presents an overview of the design of phase II and report on results from laboratory testing.

Update on the preliminary design of SCALES: the Santa Cruz Array of Lenslets for Exoplanet Spectroscopy

“…Another upgrade is to add in a single-mode (SM) fiber bundle that feeds a high-resolution (R∼ 100000) spectrograph (see §3.7, high contrast high dispersion spectroscopy 40 ). This would require an actuated pick-off mirror and reimaging optics, similar to the KPIC design, 41,42 and feed a separate spectrograph. The opto-mechanical design is discussed in §4.…”

“…High contrast, high dispersion spectroscopy (HCHD spectroscopy) utilizes Single-Mode (SM) optical fibers coupled to exoplanetary light after starlight suppression via coronagraphic techniques to feed a high-resolution (R∼ 100000) spectrograph. 40 Coupling SM fibers to exoplanetary light has been demonstrated on-sky by KPIC 41,42 using vortex coronagraphs and fiber nulling techniques with room-temperature optics feeding the cryogenic NIRSpec instrument. The SCALES HCHD spectrgraph mode, in comparison to KPIC, will have higher sensitivity due to its cryogenic coronagraph and injection optics.…”

The Keck Planet Imager and Characterizer: demonstrating advanced exoplanet characterization techniques for future extremely large telescopes (Conference Presentation)

“…To enhance the starlight suppression for the FIU arm and hence really demonstrate HDC, the 1000 element DM, as well as several coronagraphs, 15 an atmospheric dispersion compensator and pupil shaping optics will be installed upstream of the fiber feed during a later phase of the project. 16…”

Enhanced high-dispersion coronagraphy with KPIC phase II: design, assembly and status of sub-modules

“…7 Phase II consists of a series of upgrades to the FIU, which aim to maximize the planet light coupled to the fiber, while minimizing the amount of stellar leakage (important for HDC) so as to minimize the integration time to reach a given SNR. 8 Phase II is currently undergoing laboratory testing and will be deployed in the fall of 2021 to replace the phase I FIU optical layout at Keck. Here we provide an overview of the phase II design and present some of the laboratory characterization for the various sub-modules.…”