J. Dellunde et al., Transverse-mode selection and noise properties of external-cavity vertical-cavity surface-emitting lasers including multiple-reflection effects, J OPT SOC B, 16(11), 1999, pp. 2131-2139
A theoretical analysis has been undertaken of steady-state transverse-mode
selection in vertical-cavity surface-emitting lasers (VCSEL's) that are sub
ject to optical feedback in an external-cavity configuration. Multiple refl
ections in the external cavity are taken into account. The influence of the
rmal effects on mode selection is also treated, and noise properties of the
configuration are discussed. In the analysis specific attention is paid to
the competition between the two lowest-order modes (LP01 and LP11 degenera
te modes) that are appropriate to the chosen circularly symmetric vertical-
cavity surface-emitting laser structure. It is shown that preferential exci
tation of either mode can be effected by the appropriate choice of optical
feedback delay. It is also shown that multiple reflections in the external
cavity can affect the mode selection, depending on the optical feedback del
ay. Thermal effects are shown to be detrimental for transverse-mode selecti
on. Strategies for the minimization of thermal effects on mode selection ar
e also discussed. Finally, the relative intensity noise spectrum for each t
ransverse mode is shown to maintain its double-peaked structure and low mod
e-partition noise in the presence of optical feedback. A change from a twin
-peaked to a single-peaked structure of this spectrum is also observed when
the optical feedback delay is changed. (C) 1999 Optical Society of America
[S0740-3224(99)00911-X].