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Practical application of LEDs - this page is a stub

Anwendung von Lumineszenzdioden (ALD), was a multi-year research project into the practical application of light-emitting diodes (LEDs), carried out between July 1968 and March 1969 by the Institut für nachrichtentechnik (INT) – the Information Technology Institute – in East-Berlin (DDR).

The results were shared with the Ministerium für Staatssicherheit (MfS), the repressive security service of the DDR — the Stasi, where they were used for covert wireless communication [3][A].

Although INT was responsible for the research and in some cases also for the development of actual devices — a good example is the ALD-3K — the production was done elsewhere by (or on behalf of) the Stasi, whilst the practical use of the equipment was kept outside INT's view [3].

 Read the final report
ALD research for practical LED applications

ALD devices on this website
Covert infrared telephony
  1. ALD final report (German) 1
    Dipl.-Ing. E. Kube, Abschlußbericht.
    INT, July 1968 — March 1969.
  1. Document obtained from BStU [2] and kindly supplied by Detlev Vreisleben [1].

  1. Detlev Vreisleben, Personal correspondence
    November 2021.

  2. Bundesbeauftragte für die Stasi-Unterlagen (BStU) 1
    Federal Commissioner for the Stasi-Records.

  3. Dipl.-Ing. Erhard Kube, personal correspondence with Detlev Vreisleben
    Dresden, 15 October 2008.
  1. Full name: Bundesbeauftragte für die Unterlagen des Staatssicherheitsdienstes der ehemaligen Deutschen Demokratischen Republik (DDR) — Federal Commissioner for the Records of the State Security Service of the former German Democratic Republic (GDR) — officially abbreviated to BStU.
  2. Document obtained from BStU [2] and kindly supplied by Detlev Vreisleben [1].

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