Since 1994, the Navy Precision Optical Interferometer (NPOI) has operated at visual wavelengths (450 to 850 nm). Its primary Classic backend is a pupil-plane combiner that disperses the light at a resolution R ≈ 50, uses avalanche photo-diodes as photon-counting detectors, and scans interference fringes by modulating the delay at 1 kHz. The newer NPOI image-plane combiner, VISION (Tennessee State University), which is similar to CHARA’s MIRC and is currently being upgraded, dispenses with delay modulation. We are now developing a third backend to expand into the near infrared. Its primary purpose will be to stabilize the NPOI for high-resolution observations by bootstrapping from the infrared to visual wavelengths.
J. Thomas Armstrong, Henrique R. Schmitt, Sergio R. Restaino, Ellyn K. Baines, and Gerard T. van Belle, "An infrared beam combiner for wavelength bootstrapping at the NPOI," Proc. SPIE 10701, Optical and Infrared Interferometry and Imaging VI, 107010B (Presented at SPIE Astronomical Telescopes + Instrumentation: June 11, 2018; Published: 9 July 2018); https://doi.org/10.1117/12.2312284.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the proceedings. They include the speaker's narration with video of the slides and animations. Most include full-text papers. Interactive, searchable transcripts and closed captioning are now available for most presentations.
Search our growing collection of more than 22,000 conference presentations, including many plenaries and keynotes.