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.