Detection of Ionized Space Charges

In Space Static Electricity Accidents to zero. (1)

スクリーンショット 2023-11-01 144058

Yasushi Takahashi

Osaka Metropolitan University

  • SPACE SAFE (provisional)
  • PhD, University of Tokyo (2006)
  • Post doc at Kyoto University
  • Currently heads the Silicon Photonics Laboratory at Osaka Metropolitan University
  • Research area: Silicon photonics, semiconductor laser.
  • Major paper: Nature 498, 470 (2013).

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We are developing compact space charge sensors that can be used in the space industry, using silicon photonic crystal elements. 

In space, various space charges are flying around at high speeds and adversely affect electronic devices on spacecraft. Several cases of satellite abandonment caused by electronic equipment failure due to electrostatic discharge have been reported in large-scale projects in Japan. Detailed measurement data on space charge distribution in space is an indispensable piece in the new space age.

Real-time information on charged particles is essential. Our vision is to develop compact charged particle sensor that can be installed on a small satellite.


In Space Static Electricity Accidents to zero. (3)-1

Our study

We've been studying silicon (Si) photonics and recently showed that it is possible to detect ionized air molecules in space by using a variety of Si photonic crystal (PC) devices; Raman Si lasers, high-Q nanocavities, and line-defect waveguides. When ionized molecules reach the surface of these devices, surplus charges are transferred to the inside of the PC and light is absorbed (free carrier absorption). Using these properties, we have developed sensors that can detect space charge.


The sensor we have developed does not require a PiN structure, so it is highly resistant to electrostatic discharge (ESD). Compared to existing detection methods, detection by PC devices is superior in terms of size, weight, and accessibility. Furthermore, they can be placed over a wide area and simultaneously detect charged particles in various locations by fiber connection.

Detection of Ionized Space Charges-1

Our sensors will be able to prevent satellite failures due to ESD. Preventing ESD failures of small satellites, which have increased significantly in recent years, is very important in terms of reducing space debris.


If there’s anything unclear, please let me know.

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