Frequency tuning of self-pulsations in a VCSEL with a voltage-controlled saturable absorber

Summary form only given. Self-pulsating lasers are extremely useful in a variety of applications, including multimode fiber systems and optical disk readout. It is desirable to attain self-pulsating vertical-cavity surface-emitting lasers (VCSELs) because the surface-normal geometry facilitates two-dimensional array configurations and wafer-scale fabrication. We previously demonstrated on-off control of GHz-range self-pulsations in a VCSEL. In this work, we believe we demonstrate for the first time 700 MHz frequency tuning of self-pulsations in a VCSEL by using an active quantum well absorber integrated in the mirror stack. These pulsations have a 700 kHz relative frequency linewidth. We present theoretical and experimental demonstrations of a novel design criterion, whereby the absorber wavelength is slightly shorter than the lasing wavelength, leading to the negative differential resistance, which is essential to obtaining self-pulsation. By careful device design, the VCSEL can be made to self-pulsate at low absorber biases, GHz-range frequencies, and potentially at high output powers.