Simon R. Bandler, Joseph S. Adams, Edward G. Amatucci, Edgar R. Canavan, James A. Chervenak, Renata S. Cumbee, Johannes P. D. Dercksen, Michael J. DiPirro, William B. Doriese, Megan E. Eckart, Manuel Gonzalez, Janice Houston, Brian Jackson, Amir E. Jahromi, Steven J. Kenyon, Caroline A. Kilbourne, Edmund Hodges-Kluck, Ralph Kraft, Xiaoyi Li, Maxim Markevitch, Dan McCammon, Jeffrey R. Olson, Elizabeth Osborne, Kazuhiro Sakai, Daniel Patnaude, Frederick S. Porter, Damien Prêle, Peter J. Shirron, Stephen J. Smith, Terrence M. Smith, Nicholas A. Wakeham, Henk J. van Weers
{"title":"Line emission mapper microcalorimeter spectrometer","authors":"Simon R. Bandler, Joseph S. Adams, Edward G. Amatucci, Edgar R. Canavan, James A. Chervenak, Renata S. Cumbee, Johannes P. D. Dercksen, Michael J. DiPirro, William B. Doriese, Megan E. Eckart, Manuel Gonzalez, Janice Houston, Brian Jackson, Amir E. Jahromi, Steven J. Kenyon, Caroline A. Kilbourne, Edmund Hodges-Kluck, Ralph Kraft, Xiaoyi Li, Maxim Markevitch, Dan McCammon, Jeffrey R. Olson, Elizabeth Osborne, Kazuhiro Sakai, Daniel Patnaude, Frederick S. Porter, Damien Prêle, Peter J. Shirron, Stephen J. Smith, Terrence M. Smith, Nicholas A. Wakeham, Henk J. van Weers","doi":"10.1117/1.jatis.9.4.041002","DOIUrl":"https://doi.org/10.1117/1.jatis.9.4.041002","url":null,"abstract":"The line emission mapper (LEM) is a probe-class mission concept that is designed to detect x-ray emission lines from hot ionized gas (T > 106 K) that will enable us to test galaxy evolution theories. It will permit us to study the effects of stellar and black-hole feedback and flows of baryonic matter into and out of galaxies. The key to being able to study the hot gases that are otherwise invisible to current imaging x-ray spectrometers is that the energy resolution is sufficient to use cosmological redshift to separate extragalactic source lines from foreground Milky Way emission. LEM incorporates a large-format microcalorimeter array instrument called the LEM microcalorimeter spectrometer (LMS) with a light-weight x-ray optic with 10” half power diameter angular resolution. The LMS microcalorimeter array has pixels with 15″ pixel pitch over a 33′ field of view (FOV) optimized for the 0.3 to 2 keV energy band. The central 7′ region of the array has an energy resolution of 1.3 eV at 1 keV and the rest of the FOV has 2.5 eV energy resolution at 1 keV. The array will be read out with state-of-the-art time-division multiplexing. We present an overview of the LMS instrument, including details of the entire detection chain, the focal plane assembly, as well as the cooling system and overall mechanical and thermal design. For each of the key technologies, we discuss the current technology readiness level and the plan to advance them to be ready for flight. We also describe the current system design and our estimate for the mass, power, and data rate of the instrument. The design details presented concentrate primarily on the unique aspects of the LMS design compared with prior missions and confirm that the type of microcalorimeter instrument needed for LEM is not only feasible but also technically mature.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135730787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kazuhiro Sakai, Joseph S. Adams, Simon R. Bandler, Si Chen, Manuel Gonzalez, Damien Prêle, Carl D. Reintsema, Adam J. Schoenwald, Stephen J. Smith, Terrence M. Smith, Nicholas A. Wakeham
{"title":"Development of space-flight room-temperature electronics for the Line Emission Mapper Microcalorimeter Spectrometer","authors":"Kazuhiro Sakai, Joseph S. Adams, Simon R. Bandler, Si Chen, Manuel Gonzalez, Damien Prêle, Carl D. Reintsema, Adam J. Schoenwald, Stephen J. Smith, Terrence M. Smith, Nicholas A. Wakeham","doi":"10.1117/1.jatis.9.4.041004","DOIUrl":"https://doi.org/10.1117/1.jatis.9.4.041004","url":null,"abstract":"We are developing space-flight room-temperature readout electronics for the Line Emission Mapper (LEM) Microcalorimeter Spectrometer (LMS) of the LEM mission. The LEM mission is an x-ray probe mission designed to study the physics of galaxy formation. The LMS is optimized for low-energy (0.2 to 2 keV) x-ray emission from extremely diffuse gas. The detector is a hybrid transition-edge sensor (TES) microcalorimeter array with a 33′ outer array and a 7 ′ × 7 ′ inner subarray. The outer array consists of 12,736 square pixels on a square grid with a 290 μm pitch but in a close-packed hexagonal shape. The inner subarray consists of 784 TES sensors arranged in a square area in the center of the outer array with the same pixel pitch. The outer array uses a sensor with 2 × 2 thermal multiplexing known as “Hydra,” and the inner array consists of a single absorber per TES. The baselined readout technology for the 3968 TES sensors is time-division multiplexing (TDM), which divides the sensors into 69 columns × 60 rows. The components of the room temperature readout electronics are the three boxes of the warm front-end electronics (WFEE) and the six boxes of the digital electronics and event processor (DEEP). The WFEE is an interface between the cold electronics and the DEEP, and the DEEP generates signals for the TDM and processes x-ray events. We present the detailed designs of the WFEE and DEEP. We also show the estimated power, mass, and size of the WFEE and DEEP flight electronics. Finally, we describe the performance of the TRL-6 prototypes for the WFEE and DEEP electronics.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135883303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stephen J. Smith, Joseph S. Adams, Simon R. Bandler, Rachel B. Borrelli, James A. Chervenak, Renata S. Cumbee, Enectali Figueroa-Feliciano, Fred M. Finkbeiner, Joshua Furhman, Samuel V. Hull, Richard L. Kelley, Caroline A. Kilbourne, Noah A. Kurinsky, Jennette N. Mateo, Asha Rani, Kazuhiro Sakai, Nicholas A. Wakeham, Edward J. Wassell, Sang H. Yoon
{"title":"Development of the microcalorimeter and anticoincidence detector for the Line Emission Mapper x-ray probe","authors":"Stephen J. Smith, Joseph S. Adams, Simon R. Bandler, Rachel B. Borrelli, James A. Chervenak, Renata S. Cumbee, Enectali Figueroa-Feliciano, Fred M. Finkbeiner, Joshua Furhman, Samuel V. Hull, Richard L. Kelley, Caroline A. Kilbourne, Noah A. Kurinsky, Jennette N. Mateo, Asha Rani, Kazuhiro Sakai, Nicholas A. Wakeham, Edward J. Wassell, Sang H. Yoon","doi":"10.1117/1.jatis.9.4.041005","DOIUrl":"https://doi.org/10.1117/1.jatis.9.4.041005","url":null,"abstract":"The Line Emission Mapper (LEM) is an x-ray probe mission concept that is designed to provide unprecedented insight into the physics of galaxy formation, including stellar and black-hole feedback and flows of baryonic matter into and out of galaxies. LEM incorporates a light-weight x-ray optic with a large-format microcalorimeter array. The LEM detector utilizes a 14k pixel array of transition-edge sensors (TESs) that will provide <2.5 eV spectral resolution over the energy range 0.2 to 2 keV, along with a field-of-view of 30 arcmin. The microcalorimeter array and readout builds upon the technology developed for the European Space Agency’s (ESA’s) Athena/x-ray Integral Field Unit. Here, we present a detailed overview of the baseline microcalorimeter design, its performance characteristics, including a detailed energy resolution budget and the expected count-rate capability. In addition, we outline the current status and plan for continued technology maturation. Behind the LEM array sits a high-efficiency TES-based anticoincidence (antico) detector that will reject cosmic-ray background events. We will briefly describe the design of the antico and plan for continued development.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135883458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ground calibration of visible emission line coronagraph on board Aditya-L1 mission","authors":"Raghavendra Prasad Budihal, Venkata Suresh Narra, Natarajan Venkatasubramanyam, Pawan Kumar Somasundaram, Umesh Kamath Padavu, Shalabh Mishra, Bhavana Hegde, Sasikumar Raja Kantepalli, Jagdev Singh","doi":"10.1117/1.jatis.9.4.044001","DOIUrl":"https://doi.org/10.1117/1.jatis.9.4.044001","url":null,"abstract":"Visible emission line coronagraph (VELC) is the prime payload on board India’s first space solar observatory Aditya-L1. VELC is a unique payload with simultaneous observational capabilities in imaging, spectroscopy, and spectro polarimetry modes. VELC is capable of achieving high spatial, spectral, and temporal resolution closer to the solar limb 1.05 R ⊙ compared to the existing space and ground-based solar coronagraphs. VELC consists of a total of 44 optical elements in 18 groups, which are custom designed and developed to meet the desired performance requirements. In addition, it consists of four mechanisms out of which two are multioperational with expected life cycle of million operations. Four detectors (three sCMOS and one InGaAs) are used to record the data. The performance of the payload depends on the performance of individual element, subsystems, and the system level performance of all the elements (such as optics, mechanism, and detectors) together. To ensure the desired performance levels are achieved, each element/subsystem should be tested prior to integrating them together. Evaluation of performance of the integrated system is essential to validate the payload capabilities to meet the proposed science goals. This paper summarizes the calibration tests carried out on the integrated system and compares the results obtained with respect to the design requirements to meet the proposed science goals.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135992877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Charles Townsend-Rose, Thomas Buggey, James Ivory, Konstantin D. Stefanov, Lawrence Jones, Oliver Hetherington, Andrew D. Holland, Thibaut Prod’homme
{"title":"Electro-optical characterization of a CMOS image sensor optimized for soft x-ray astronomy","authors":"Charles Townsend-Rose, Thomas Buggey, James Ivory, Konstantin D. Stefanov, Lawrence Jones, Oliver Hetherington, Andrew D. Holland, Thibaut Prod’homme","doi":"10.1117/1.jatis.9.4.046001","DOIUrl":"https://doi.org/10.1117/1.jatis.9.4.046001","url":null,"abstract":"CIS221-X is a prototype complementary metal-oxide-semiconductor (CMOS) image sensor, optimized for soft x-ray astronomy and developed for the proposed ESA Transient High Energy Sky and Early Universe Surveyor (THESEUS) mission. The sensor features 40 μm pitch square pixels built on a 35 μm thick, high-resistivity epitaxial silicon that is fully depleted by reverse substrate bias. Backside illumination processing has been used to achieve high x-ray quantum efficiency, and an optical light-blocking filter has been applied to mitigate the influence of stray light. A comprehensive electro-optical characterization of CIS221-X has been completed. The median readout noise is 3.3 e − RMS with 90% of pixels reporting a value <3.6 e − RMS. At −40 ° C, the dark current is 12.4 ± 0.06 e − / pixel / s. The pixel photo-response is linear to within 1% for 0.3 to 5 keV photons (82 to 1370 e − ) with <0.1 % image lag. Following per-pixel gain correction, an energy resolution of 130.2 ± 0.4 eV has been measured at 5898 eV. In the 0.3 to 1.8 keV energy range, CIS221-X achieves >80 % quantum efficiency. With the exception of dark current, these results either meet or outperform the requirements for the THESEUS mission, strongly supporting the consideration of CMOS technology for soft x-ray astronomy.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135766510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jonah T. Hansen, Samuel Wade, Michael J. Ireland, Tony D. Travouillon, Tiphaine Lagadec, Nicholas Herrald, Joice Mathew, Stephanie Monty, Adam D. Rains
{"title":"Pyxis: a ground-based demonstrator for formation-flying optical interferometry","authors":"Jonah T. Hansen, Samuel Wade, Michael J. Ireland, Tony D. Travouillon, Tiphaine Lagadec, Nicholas Herrald, Joice Mathew, Stephanie Monty, Adam D. Rains","doi":"10.1117/1.jatis.9.4.045001","DOIUrl":"https://doi.org/10.1117/1.jatis.9.4.045001","url":null,"abstract":"In the past few years, there has been a resurgence in studies of space-based optical/infrared interferometry, particularly with the vision to use the technique to discover and characterize temperate Earth-like exoplanets around solar analogs. One of the key technological leaps needed to make such a mission feasible is demonstrating that formation flying precision at the level needed for interferometry is possible. Here, we present Pyxis, a ground-based demonstrator for a future small satellite mission with the aim to demonstrate the precision metrology needed for space-based interferometry. We describe the science potential of such a ground-based instrument and detail the various subsystems: three six-axis robots, a multi-stage metrology system, an integrated optics beam combiner, and the control systems required for the necessary precision and stability. We conclude by looking toward the next stage of Pyxis: a collection of small satellites in Earth orbit.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136098358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
John E. Krist, John B. Steeves, Brandon D. Dube, A J Eldorado Riggs, Brian D. Kern, David S. Marx, Eric J. Cady, Hanying Zhou, Ilya Y. Poberezhskiy, Caleb W. Baker, James P. McGuire, Bijan Nemati, Gary M. Kuan, Bertrand Mennesson, John T. Trauger, Navtej S. Saini, Sergi Hildebrandt Rafels
{"title":"End-to-end numerical modeling of the Roman Space Telescope coronagraph","authors":"John E. Krist, John B. Steeves, Brandon D. Dube, A J Eldorado Riggs, Brian D. Kern, David S. Marx, Eric J. Cady, Hanying Zhou, Ilya Y. Poberezhskiy, Caleb W. Baker, James P. McGuire, Bijan Nemati, Gary M. Kuan, Bertrand Mennesson, John T. Trauger, Navtej S. Saini, Sergi Hildebrandt Rafels","doi":"10.1117/1.jatis.9.4.045002","DOIUrl":"https://doi.org/10.1117/1.jatis.9.4.045002","url":null,"abstract":"The Roman Space Telescope will have the first advanced coronagraph in space, with deformable mirrors (DMs) for wavefront control (WFC), low-order wavefront sensing and maintenance, and a photon-counting detector. It is expected to be able to detect and characterize mature, giant exoplanets in reflected visible light. Over the past decade, the performance of the coronagraph in its flight environment has been simulated with increasingly detailed diffraction and structural/thermal finite-element modeling. With the instrument now being integrated in preparation for launch within the next few years, the present state of the end-to-end modeling, including the measured flight components such as DMs, is described. The coronagraphic modes, including characteristics most readily derived from modeling, are thoroughly described. The methods for diffraction propagation, WFC, and structural and thermal finite-element modeling are detailed. The techniques and procedures developed for the instrument will serve as a foundation for future coronagraphic missions, such as the Habitable Worlds Observatory.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136062728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bijan Nemati, John Krist, Ilya Poberezhskiy, Brian Kern
{"title":"Analytical performance model and error budget for the Roman coronagraph instrument","authors":"Bijan Nemati, John Krist, Ilya Poberezhskiy, Brian Kern","doi":"10.1117/1.jatis.9.3.034007","DOIUrl":"https://doi.org/10.1117/1.jatis.9.3.034007","url":null,"abstract":"The Nancy Grace Roman Space Telescope (“Roman”), under development by NASA, will investigate possible causes for the phenomenon of dark energy and detect and characterize extrasolar planets. The 2.4 m space telescope has two main instruments: a wide-field, infrared imager and a coronagraph. The coronagraph instrument (CGI) is a technology demonstrator designed to help bridge the gap between the current state-of-the-art space and ground instruments and future high-contrast space coronagraphs that will be capable of detecting and characterizing Earth-like planets in the habitable zones of other stars. Using adaptive optics, including two high-density deformable mirrors and low- and high-order wavefront sensing and control, CGI is designed to suppress the star light by up to nine orders of magnitude, potentially enabling the direct detection and characterization of Jupiter-class exoplanets. Contrast is the measure of starlight suppression, and high contrast is the chief virtue of a coronagraph. But it is not the only important characteristic: contrast must be balanced against acceptance of planet light. The remaining unsuppressed starlight must also have a stable morphology to allow further estimation and subtraction. To achieve all these goals in the presence of the disturbance and radiation environment of space, the coronagraph must be designed and fabricated as a highly optimized system. The CGI error budget is the top-level tool used to guide the optimization, enabling trades of various competing errors. The error budget is based on an analytical model, which enables rapid calculation and tracking of performance for the numerous and diverse questions that arise in the system engineering process. We outline the coronagraph system engineering approach and the error budget. We then describe in detail the analytical model for direct imaging and spectroscopy and show how it connects to the error budget. We introduce a number of useful ancillary metrics that provide insight into the capabilities of the instrument. Since models always need to be validated, we describe the validation approach for the CGI analytical model.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135470984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Daniel Echeverri, Jerry Xuan, Nemanja Jovanovic, Garreth Ruane, Jacques-Robert Delorme, Dimitri Mawet, Bertrand Mennesson, Eugene Serabyn, J. Kent Wallace, Jason Wang, Jean-Baptiste Ruffio, Luke Finnerty, Yinzi Xin, Maxwell Millar-Blanchaer, Ashley Baker, Randall Bartos, Benjamin Calvin, Sylvain Cetre, Greg Doppmann, Michael P. Fitzgerald, Sofia Hillman, Katelyn Horstman, Chih-Chun Hsu, Joshua Liberman, Ronald Lopez, Evan Morris, Jacklyn Pezzato, Caprice L. Phillips, Bin B. Ren, Ben Sappey, Tobias Schofield, Andrew J. Skemer, Connor Vancil, Ji Wang
{"title":"Vortex fiber nulling for exoplanet observations: implementation and first light","authors":"Daniel Echeverri, Jerry Xuan, Nemanja Jovanovic, Garreth Ruane, Jacques-Robert Delorme, Dimitri Mawet, Bertrand Mennesson, Eugene Serabyn, J. Kent Wallace, Jason Wang, Jean-Baptiste Ruffio, Luke Finnerty, Yinzi Xin, Maxwell Millar-Blanchaer, Ashley Baker, Randall Bartos, Benjamin Calvin, Sylvain Cetre, Greg Doppmann, Michael P. Fitzgerald, Sofia Hillman, Katelyn Horstman, Chih-Chun Hsu, Joshua Liberman, Ronald Lopez, Evan Morris, Jacklyn Pezzato, Caprice L. Phillips, Bin B. Ren, Ben Sappey, Tobias Schofield, Andrew J. Skemer, Connor Vancil, Ji Wang","doi":"10.1117/1.jatis.9.3.035002","DOIUrl":"https://doi.org/10.1117/1.jatis.9.3.035002","url":null,"abstract":"Vortex fiber nulling (VFN) is a single-aperture interferometric technique for detecting and characterizing exoplanets separated from their host star by less than a diffracted beam width. VFN uses a vortex mask and single mode fiber to selectively reject starlight while coupling off-axis planet light with a simple optical design that can be readily implemented on existing direct imaging instruments that can feed light to an optical fiber. With its axially symmetric coupling region peaking within the inner working angle of conventional coronagraphs, VFN is more efficient at detecting new companions at small separations than conventional direct imaging, thereby increasing the yield of on-going exoplanet search campaigns. We deployed a VFN mode operating in K band ($2.0{-}2.5~mu$m) on the Keck Planet Imager and Characterizer (KPIC) instrument at the Keck II Telescope. In this paper we present the instrument design of this first on-sky demonstration of VFN and the results from on-sky commissioning, including planet and star throughput measurements and predicted flux-ratio detection limits for close-in companions. The instrument performance is shown to be sufficient for detecting a companion $10^3$ times fainter than a $5^{mathrm{th}}$ magnitude host star in 1 hour at a separation of 50 mas (1.1$lambda/D$). This makes the instrument capable of efficiently detecting substellar companions around young stars. We also discuss several routes for improvement that will reduce the required integration time for a detection by a factor ${>}$3.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135826998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}