Positive and negative optical responses in high-electron mobility transistors and their applications to optically controlled microwave oscillators

Atsushi Ishikawa, Hiroshi Murata, Takuo Tanaka, Hidehisa Shiomi, Yasuyuki Okamura, Sadahiko Yamamoto

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6 Citations (Scopus)


We investigated optical responses of high-electron mobility transistors (HEMTs) by the use of a tightly focused optical beam. Positive and negative optical responses in the HEMTs were observed according to the irradiation position of the optical beam. The positive optical response was obtained by the optical beam irradiation close to the gate electrodes of the HEMTs with appropriate DC-bias voltages. While the negative optical response was obtained by the optical beam irradiation away from the gate electrodes. The light-induced increase and decrease of the drain currents were observed over 1 mA by the irradiation of a 10 μW CW light beam. The increase and decrease by as much as 5 dB of the small signal gain of the HEMTs in the microwave frequency range were also observed. We also applied these irradiation-position-dependent positive and negative optical responses to the optical control of the microwave oscillator composed of the HEMT. Microwave oscillations at 11.7 GHz from the oscillator were switched between "ON" and "OFF" by the selective irradiation of the successive focused light pulses.

Original languageEnglish
Pages (from-to)997-1001
Number of pages5
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Issue number3
Publication statusPublished - Mar 2004



  • HEMT
  • Microwave oscillator
  • Negative optical response
  • Optical mixing
  • Side-gating effect

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)

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