Feature Of The Week 7/3/11: Swept-Source Laser Based on a Quantum Dot Semiconductor Optical Amplifier
Researchers at the University of Sheffield have been very active in publishing novel results on high performance semiconductors for Optical Coherence Tomography. Recently in collaboration with Innolume they published on a swept-source laser based on a quantum-dot semiconductor optical amplifier. Below is a summary of that work.
Swept source lasers (SSL) are a crucial component in Fourier domain optical coherence tomography (OCT) systems. Most SSLs use semiconductor optical amplifiers (SOA) as the gain medium. By cleverly manipulating cavity configurations, SSLs have achieved amazing speeds up to MHz sweep frequencies. Most SOAs used are quantum well (QW) designs. Here we present work done on a novel quantum dot (QD) SOA. QD designs hold promise for higher power and bandwidth while keeping the prices similar to QW devices. We present a swept-source laser based on a QD SOA (designed and manufactured by Innolume GmbH, Germany) as the gain medium. The properties of the laser are as follows: center wavelength is 1220 nm, sweep range is 94 nm (up to 120 nm in manual mode), the peak laser power is 16 mW, and the sweep speed is 100 Hz. We apply the laser in an OCT configuration and present images of in vivo skin. QD SOA are well suited to OCT and we show the setup can be improved for power, sweep range and sweep speed.
For more information see recent Article. Courtesy Nikola Krstajic.