Interstellar communication. II. Application to the solar gravitational lens

Abstract

We have shown in paper I of this series (arXiv:1706.03795) that interstellar communication to nearby (pc) stars is possible at data rates of bits per second per Watt between a 1 m sized probe and a large receiving telescope (E-ELT, 39 m), when optimizing all parameters such as frequency at 300-400 nm. We now apply our framework of interstellar extinction and quantum state calculations for photon encoding to the solar gravitational lens (SGL), which enlarges the aperture (and thus the photon flux) of the receiving telescope by a factor of $>10^9$. For the first time, we show that the use of the SGL for communication purposes is possible. This was previously unclear because the Einstein ring is placed inside the solar coronal noise, and contributing factors are difficult to determine. We calculate point-spread functions, aperture sizes, heliocentric distance, and optimum communication frequency. The best wavelength for nearby (<100 pc) interstellar communication is limited by current technology to the UV and optical band. To suppress coronal noise, an advanced coronograph is required, alternatively an occulter could be used which would require a second spacecraft in formation flight 78 km from the receiver, and ~10 m in size. Data rates scale approximately linear with the SGL telescope size and with heliocentric distance. Achievable (receiving) data rates from Alpha Cen are 1-10 Mbits per second per Watt for a pair of meter-sized telescopes, an improvement of $10^6$ compared to using the same receiving telescope without the SGL. A 1 m telescope in the SGL can receive data at rates comparable to a km-class "normal" telescope.

arXiv comment14 pages, 11 figures. Accepted for publication in Acta Astronautica

References in corpus (18)

• A terrestrial planet candidate in a temperate orbit around Proxima Centauri
• A sub-40 mHz linewidth laser based on a silicon single-crystal optical cavity
• Prospects for a mHz-linewidth laser
• Theoretical Limits on Extrasolar Terrestrial Planet Detection with Coronagraphs
• Proxima's orbit around Alpha Centauri
• Science performance of Gaia, ESA's space-astrometry mission
• Ultimate communication capacity of quantum optical channels by solving the Gaussian minimum-entropy conjecture
• Optimal Occulter Design for Finding Extrasolar Planets
• Diffraction of electromagnetic waves in the gravitational field of the Sun
• Close stellar conjunctions of alpha Centauri A and B until 2050 - An mK = 7.8 star may enter the Einstein ring of alpha Cen A in 2028
• Analytic Modeling of Starshades
• Gravitational Lensing Characteristics of the Transparent Sun
• Deceleration of high-velocity interstellar photon sails into bound orbits at $\alpha$ Centauri
• The 550 AU Mission: A Critical Discussion
• Optimized trajectories to the nearest stars using lightweight high-velocity photon sails
• A novel SETI strategy targeting the solar focal regions of the most nearby stars
• Design of a telescope-occulter system for THEIA
• Interstellar communication. I. Maximized data rate for lightweight space-probes

Cited by in corpus (6)

• Relative Likelihood of Success in the Searches for Primitive versus Intelligent Extraterrestrial Life
• A mission architecture to reach and operate at the focal region of the solar gravitational lens
• Interstellar communication network. I. Overview and assumptions
• Gravitational lensing for interstellar power transmission
• Interstellar communication. III. Optimal frequency to maximize data rate
• Wave optics of the solar gravity lens