Heterodyne pump-probe and four-wave mixing in semiconductor optical amplifiers using balanced lock-in detection

Paola Borri, Wolfgang Langbein, Jesper Mørk, Jørn Marcher Hvam

Research output: Contribution to journalJournal articleResearchpeer-review


We demonstrate a new detection scheme for pump-probe and four-wave mixing heterodyne experiments, using balanced detection and a dual-phase lock-in for spectral filtering. The technique allows the use of low repetition-rate laser systems, as is demonstrated on an InGaAsP/InP bulk optical amplifier at 1.53 mym. Ultrafast pump-induced changes in the amplitude and phase of the transmitted probe signal are simultaneously measured, going from small to large signal changes and with no need of an absolute phase calibration, showing the versatility and the sensitivity of this detection scheme. The results for small perturbations are consistent with previous pump-probe experiments reported in literature. Time-resolved four-wave mixing in the absorption regime of the device is measured, and compared with numerical simulations, indicating a 100 fs dephasing time.
Original languageEnglish
JournalOptics Communications
Pages (from-to)317-324
Publication statusPublished - 1999

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