Highly reliable oxide VCSELs for datacom applications

High speed (>13 GHz) modulation of 850 nm vertical cavity surface emitting lasers (VCSELs) with tapered oxide confined layer

“…The main advantages of VCSELs are low threshold current, low divergence angle, and circular beam, leading to simpler packaging and low electrical power consumption. The surface emission property of VCSELs also simplifies the 2-dimensional arrays and enables wafer level testing, thus low fabrication cost [1]. For optical communication applications, high modulation bandwidth is desirable.…”

Reliability investigation and failure analysis of 25Gb/s 850 nm oxide-confined VCSELs

“…Similarly, for parameter n, the aging data under different bias currents are obtained to obtain the linear relationship between ln(MFT) and ln(𝐼/𝐼 0 ), and the absolute value of the slope of the curve obtained from the fitting is the current acceleration factor n. It should be noted that the effect of junction temperature needs to be subtracted in the process of obtaining n, and the average value of the current acceleration factor obtained in the present study is 11.4. The lifetime model parameters of the 850 nm 25 Gb/s VCSELs with InGaAs QWs in this study (Ea = 2.01 eV, n = 11.4) are much larger than those of the 850 nm 10 Gb/s VCSELs with GaAs QWs (Ea = 0.7 eV, n = 2) [9][10][11], due to the fact that the addition of In to the QWs creates compressive strain in the lattice structure generates compressive strain, and the strain reduces the mobility of certain dislocations and other crystal defects, increasing the activation energy for reliability testing. In some cases, the presence of endogenous strain can even cause dislocations to loop back around and immobilize themselves, thus preventing further diffusion and degradation.…”

Stress test of lithographic vertical‐cavity surface‐emitting lasers under extreme operating conditions

“…The dependence of reliability on current density and junction temperature for VCSELs is well known and expressed as [5–10] where t f is the failure time, A is a scaling factor, J is the current density, E a is the activation energy, k is the Boltzmann constant, T j is the junction temperature and N is the current acceleration factor. The junction temperature T j in the exponential term will mostly affect the time to fail and is the focus of this Letter.…”