Vertical‐Cavity Surface‐Emitting Lasers for Ultra‐High Speed Photonics

Abstract

We propose a vertical‐cavity surface‐emitting laser (VCSEL) with a transverse‐coupledcavity (TCC) for a larger enhancement of the modulation bandwidth used in ultra‐highspeed photonics. The dynamics of the TCC‐VCSEL were analyzed over three characteristic regimes of OFB that correspond to continuous wave (CW) operation, pulsation, and chaos, depending on the coupling ratio between the VCSEL and feedback cavities. The intensity noise was evaluated in terms of the frequency spectrum of the relative intensity noise (RIN) and the carrier to noise ratio (CNR). The results show that strong lateral OFB can boost the modulation bandwidth to frequencies approaching 70 GHz. The free‐running TCC‐VCSEL follows CW operation, pulsation, and then chaos with the increase of coupling ratio. Under weak OFB, RIN is lowest under CW operation, increases under pulsing, and is pronounced in the chaos region. A TCC VCSEL with a short feedback cavity shows a stable CW operation without noticeable change in either RIN or CNR.