Self pulsing quantum dot lasers for optical coherence tomography

摘要

In this paper, we will discuss the necessary properties of the light source needed for high resolution and high penetration OCT. We examine the performance of a self pulsating edge emitting quantum dot laser diode light source emitting at ～1050nm and configured as a split contact device with separate gain and absorber sections. The device can be configured to operate with a reverse biased saturable absorber section or with the whole device forward biased into gain. With the device operated without a saturable absorber section the laser emits a number of discrete narrow modes, which merge to form a broad continuous lasing spectrum (width up to 10nm) on application of the saturable absorber. In the time domain we observe continuous emission that becomes self pulsation, with pulse widths of 200-300ps and frequency of 0.6 -1.5GHz depending on drive current and reverse bias, on application of the saturable absorber.