Investigation of data transmission characteristics of polarisation-controlled 850 nm GaAs-based VCSELs grown on (311)B substrates

Polarization control of 1.6 μm vertical-cavity surface-emitting lasers using InAs quantum dashes on InP(001)

“…[5][6][7][9][10][11] We believe that the fixed polarization and such an important and stable OPSR are mainly due to the QDH in-plane optical anisotropy. Ukhanov et al 20 have reported a QDH TE gain ratio close to 2 in linear SOA, depending of the QDH alignment ͑parallel or perpendicular͒ in reference to the SOA cavity axis.…”

“…As a consequence, introduced in high speed datalinks, VCSEL, due to their polarization instabilities, cause increase in intensity noise and degradation in bit error rates. 5 This VCSEL polarization instability has been studied by several groups and gets its origin from the in-plane intrinsic properties of VCSEL, from the cylindrical geometry of the cavity, the gain media and distributed Bragg reflector index isotropies. [6][7][8] Several methods have been proposed to break these symmetries and produce polarization stable VCSEL emission with different degrees of success.…”

“…For example VCSELs based on noncylindrical cavities, on spatial gain or loss anisotropy, on the use of external stress or optical feedback have been successfully realized. 5,[9][10][11] They show a polarization control toward a specific direction, with an orthogonal polarization suppression ratio ͑OPSR͒ being for the best value close to 30 dB. Nevertheless, most of these realizations increase the fabrication complexity and cost.…”

“…As already reported, we experimentally observed that the QW VCSEL dominant polarization switches on the sample, the extracted OPSR varying from 26 dB down to Ϫ14 dB, in a very dispersive way. [5][6][7][8][9] In opposite, Fig. 3͑b͒ represents the measurements for the QDH VCSELs.…”

InAs quantum wires on InP substrate for VCSEL applications

“…They present the opportunity to benefit from an efficient coupling with optical fibers thanks to their circular beam, a spectral purity, and a high modulation bandwidth (typically 2-5 Gb/s) [1]. Because of this circular symmetry, the isotropic gain afforded by quantum wells (QWs) and the polarization independent reflectivity of Bragg mirrors, conventional QW VCSELs suffer from an optical output polarization instability, leading to an increase of the bit error data rates in optical telecommunication networks [2][3]. Several approaches have been conducted in order to control the VCSEL output polarization The use of a surface grating mirror [4], an asymmetric cavity [5], an external polarized optical excitation [6], have shown improved performances.…”