Q-switched Erbium-doped fiber laser at 1600 nm for photoacoustic imaging application

• Published in: Applied physics letters Vol. 108; no. 14; p. 143701
• Main Authors: Piao, Zhonglie, Zeng, Lvming, Chen, Zhongping, Kim, Chang-Seok
• Format: Journal Article
• Language: English
• Published: United States 04.04.2016
• DOI: 10.1063/1.4945711
• ISSN: 0003-6951

We present a nanosecond Q-switched Erbium-doped fiber (EDF) laser system operating at 1600 nm with a tunable repetition rate from 100 kHz to 1 MHz. A compact fiber coupled, acousto-optic modulator-based EDF ring cavity was used to generate a nanosecond seed laser at 1600 nm, and a double-cladding EDF based power amplifier was applied to achieve the maximum average power of 250 mW. In addition, 12 ns laser pulses with the maximum pulse energy of 2.4  J were obtained at 100 kHz. Furthermore, the Stokes shift by Raman scattering over a 25 km long fiber was measured, indicating that the laser can be potentially used to generate the high repetition rate pulses at the 1.7  m region. Finally, we detected the photoacoustic signal from a human hair at 200 kHz repetition rate with a pulse energy of 1.2  J, which demonstrates that a Q-switched Er-doped fiber laser can be a promising light source for the high speed functional photoacoustic imaging.