Diode lasers in external cavities with frequency-shifted feedback

P. I. Richter, T. W. Hänsch

Research output: Contribution to journalArticle

33 Citations (Scopus)


We have investigated the spectral broadening of diode lasers in an external linear cavity with frequency-shifted feedback. With an 850 nm infrared diode of 30 MHz free running bandwidth, we observe a feedback level dependent frequency shift and continuous line broadening up to 5 GHz. A 660 nm visible laser diode exhibits a symmetric broadening enhanced by relaxation oscillations and, at large feedback levels, multimode operation over a bandwidth up to 1 THz, tunable over 3.1 THz (44 Å). In each case, the acousto-optic frequency shifter prevents constructive interference of successive roundtrips inside the external cavity and thus the build-up of a discrete axial mode spectrum.

Original languageEnglish
Pages (from-to)414-418
Number of pages5
JournalOptics Communications
Issue number5-6
Publication statusPublished - Oct 1 1991


ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Physical and Theoretical Chemistry
  • Electrical and Electronic Engineering

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