Dynamics and feedback sensitivity of vertical-cavity surface-emitting lasers with arbitrary optical feedback intensity

Abstract

Vertical cavity surface emitting lasers (VCSELs) are the key laser sources in the high-performance computers and data centers. The explosive growth of data traffic in the high-performance computers and data centers requires increased bandwidths of VCSELs. In this paper, we deduce the Time-Delay (T-D) model with considering the multiple round trips of light in VCSELs with an optical feedback cavity to enhance the modulation bandwidth. The T-D model is suitable for the VCSEL with an arbitrary optical feedback intensity. The influences of the round trip time m of light in the optical feedback cavity on the intensity-modulation responses (IM-responses) with strong and weak optical feedback are studied. The feedback coefficients with considering the multiple round trips of light in the optical feedback cavity and the dispersions of the distributed Bragg reflector (DBR) are deduced, and are suitable for the arbitrary optical feedback intensity. The feedback coefficients are influenced by the value of m and the optical feedback intensity, and decrease as the increase of the value of m under arbitrary optical feedback intensity. The feedback coefficients under strong optical feedback are larger than that under weak optical feedback with the same value of m. The theories are useful for the high-speed VCSELs with optical feedback.

Dynamics of Semiconductor Laser Coupled with Two External Cavities

“…We will start by assuming that the distance between the first and second reflectors is 5 × 10 −3 m, making the cavity of the double OFB in the short cavity region (L ex2 = 3.5 × 10 −2 m). Dynamic states of lasers with short external cavities are highly influenced by the number of round-trips in short external cavities [32]. In this paper, we consider the number of round-trips in our simulations.…”