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Lasing and Anti-Lasing in a Single Cavity

Lasing and Anti-Lasing in a Single Cavity(A) SEM image of the device. (B) Coherent amplification and absorption of ±15 dB are attained at the same wavelength of 1555.8 nm.

Scientific Achievement
We experimentally demonstrated lasing and anti-lasing at the same frequency in a single device

Significance and Impact
Offers a new route for light modulation with extremely high contrast approaching the ultimate limit

Research Details

  • Laser and anti-laser (or coherent perfect absorber) fundamentally contradict each other
  • By carefully engineering the loss (Cr/Ge) and gain (InGaAsP) materials to satisfy the parity-time symmetric condition, lasing and anti-lasing can both be attained in a single device
  • In-phase coherent amplification (due to lasing mode) and coherent absorption (due to anti-lasing mode) are experimentally observed at the same wavelength using a pump-probe measurement setup

Z. J. Wong, Y-L Xu, J Kim, K O’Brien, Y Wang, L Feng, X Zhang, Nature Photonics (2016) DOI: 10.1038/nphoton.2016.216