Near InfraRed and Optical Search for Extraterrestrial Intelligence (NIROSETI) instrument


NIROSETI Description

The Near-Infrared Optical SETI (NIROSETI) instrument is the first instrument of its kind designed to search for signals from extraterrestrials at near-Infrared wavelengths. The near-infrared regime is an optimal spectral region to search for signals from extraterrestrials, since it offers a unique window for interstellar communication with less interstellar extinction than in the visible regime.

The NIROSETI instrument utilizes two near-infrared (950 - 1650 nm) discrete amplification Avalanche Photodiodes (APD), each with > 1 GHz bandwidths and low noise characteristics, to be able to detect artificial, very fast (nanosecond) pulses of infrared radiation.

The NIROSETI instrument, which is mounted on the Nickel 1-m telescope at Lick Observatory, splits the incoming near-infrared light onto two channels, and then uses APDs to check for coincident events, which indicate signals that are detected by both detectors simultaneously.


First light on March 14th, 2015

Observing about 2,000 celestial objects

High-speed infrared detectors working in coincidence

High-time resolution Astronomy

The NIROSETI experiment

There has been growing interest in searches for fast (nanosecond) optical pulses emanating from transmitting beacons from extraterrestrial intelligence (e.g. OSETI). Near-infrared offers a unique window to search for nanosecond pulses that has remained unexplored. One major advantage for interstellar communication of using near-infrared wavelengths rather than visible is the decrease in interstellar extinction, which is of particular importance for communicating in Milky Way plane. Near-infrared (1000 - 3500 nm) astronomy has matured rapidly in the last decade, with more advanced infrared detectors offering higher quantum efficiencies and lower detector noise. At the same time, near-infrared lasers and detectors are being developed and explored for a variety of applications, in particular within the telecommunications industry. Taken together this makes the near-infrared a viable area for SETI searches, and currently today’s technology has the necessary capabilities for conducting such a search.

On Right: NIROSETI initial 3-D design (© R. Treffers, Starman Systems)

The NIROSETI instrument

The most powerful laser beams ever created (e.g. LFEX) can produce optical pulses with 2 petawatts (2.1015W) peak power for an incredibly short duration, approximately one picosecond. Such lasers would outshine our sun by several order of magnitudes if seen by a distant receiver. It can be shown that strong pulsed signals at nanosecond (or faster) intervals can be distinguishable from any known astrophysical sources. We have constructed a new innovative near-infrared SETI instrument (referred to as NIROSETI) to search for near-infrared nanosecond pulses. This project makes use of near-infrared (950 – 1650 nm) discrete amplification Avalanche Photodiodes (APDs) that have > 1 GHz bandwidths with low noise characteristics and moderate gain. The detection system uses beam splitters and two fast APDs to check for coincident events (signals in both detectors simultaneously). This instrument was recently commissioned at the Nickel 1-m telescope ( Lick Observatory ). Our primary aim is to search not only for transient phenomena from technological activity, but also from natural objects that might produce very short time scale pulses from transient sources.

On Left: Example of simultaneous raw waveforms produced with the two APDs.

Innovative instrumentation

The NIROSETI instrument is equipped with two near-infrared Discrete Amplification Photo-Diode (APDs), which are InGaAs photo-detectors designed for the analog detection of extremely low-level light signals (from one photon to several thousand photons), in the (950nm to 1650nm) spectral range. A camera working in the visible is also used for accurate guiding and for alignment purposes. Several reimaging optics, in addition to a dichroic splitting visible and near-infrared light, as well as a beam splitter to split the near-infrared light onto the two detectors have been implemented. A source unit, capable of generating near-infrared nanosecond pulses have been designed, built and integrated into the instrument to test the instrument capability to detect short pulses. The pulses are produced with a near-infrared laser, a pulser, an optical fiber and a collimator mounted on a stage to send the light onto the optical axis.

On Right: Inside view of the NIROSETI instrument (© Laurie Hatch).

Collaborative Research

This instrument and project is made possible by the generous support of the Bloomfield Family Foundation. The NIROSETI instrument design builds upon the past Lick optical SETI instrument and is the first step toward a new, more versatile and sophisticated generation of very fast near-infrared pulse search devices. We also would like to give special thanks to Lick Observatory and Amplification Technologies for giving support.
  • University of California, San Diego: Shelley Wright (PI), Melisa Tallis, Andres Duenas
  • University of California, Berkeley: Dan Werthimer (co-PI, Space Sciences Laboratory), Andrew Siemon (Berkeley SETI Research Center), Geoff Marcy
  • University of California, Lick Observatory: Rem Stone
  • University of Toronto: Jérôme Maire (Dunlap Institute), Patrick Dorval (Dunlap Institute)
  • Starman Systems: Richard Treffers
  • SETI Institute: Frank Drake
For information on observing with NIROSETI, please visit the NIROSETI observers page (internal use only). NIROSETI Observers page For more optical SETI photographs, please visit Laurie Hatch’s collection: Laurie Hatch Photography

On Left: NIROSETI team (from left to right): Rem Stone (UCO/Lick Observatory), Dan Werthimer (UC Berkeley), Jérôme Maire (University of Toronto), Shelley Wright (UC San Diego), Patrick Dorval (University of Toronto), Richard Treffers (Starman Systems). (Image © Laurie Hatch)

Bottom images: Various pics of the instrument being mounted at the Nickel telescope (© Laurie Hatch). On-sky microsecond-exposure images. Measured periodograms. All-sky Lick Observatory camera image (© UCOLick).