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The degradation mechanism of a vertical-cavity surface-emitting laser (VCSEL) with an air-post structure is analyzed for stable optical parallel interconnection communication. It is clarified that the degradation is caused by the behavior of latent defects in the GaAs active layer. Decreasing the defects in the active region as well as decreasing the threshold current is important for obtaining a long-lifetime VCSEL [ABSTRACT FROM PUBLISHER]

We demonstrate the polarization stability of 850-nm-wavelength vertical cavity surface-emitting lasers (VCSELs) grown on (311)B substrates under continuous-wave (CW) and dynamic operation. To clearly verify the polarization stability of VCSELs on (311)B substrates due to the anisotropic optical gain, the characteristics of both VCSELs on (311)B and (100) substrates were compared experimentally. Under CW operation, very small difference in both orthogonal polarization suppression ratio and the distribution of polarization direction was observed between VCSELs on (311)B and (100) polyimide-buried structures. On the other hand, significantly larger orthogonal polarization suppression ratio was obtained for VCSELs on (311)B substrates than those on (100) substrates under zero-bias modulation. Time-dependent orthogonal polarization suppression ratio measurements also showed that the orthogonal polarization suppression ratios of the VCSEL on (311)B substrates were more stable than those on (100) substrates. The data transmission characteristics also indicate large differences in the dependence of the bit error rate on bias current and the power penalty between polarization resolved and unresolved systems between VCSELs on (311)B and (100) substrates. The beneficial effect of the polarization stability of VCSELs on (311)B substrates due to their anisotropic optical gain is clearly demonstrated [ABSTRACT FROM PUBLISHER]

We report a record low threshold current of 1.55-μm vertical-cavity surface-emitting laser (VCSEL). Thin-film wafer-fusion technology enables InP-based buried heterostructure VCSELs to be fabricated on GaAs-AlAs distributed Bragg reflectors. Threshold current density is independent of mesa size, and a 5-μm VCSEL exhibits a threshold current as low as 380 μA at 20°C and a single transverse mode up to the maximum optical output power under continuous-wave operation [ABSTRACT FROM PUBLISHER]

All metal-organic chemical vapor deposition (MOCVD) grown 850-nm-wavelength refractive-index-guided semiconductor-buried vertical-cavity surface-emitting laser is proposed and their performance is investigated. P/n-InGaP current-blocking region enables both selective regrowth and the formation of refractive-index-guided region which surrounds multiquantum-well active/core regions. We have achieved room temperature CW operation of the new types of vertical-cavity surface-emitting lasers. The minimum threshold current was 9.5 mA with 18 μm square mesa size at 30°C. The device lased at up to 70°C, and the maximum output power exceeds 1 mW at above 30°C. The near field pattern indicates the single-lobed output beam at low bias current [ABSTRACT FROM PUBLISHER]

The polarization stability of 850-nm GaAs-based vertical-cavity surface-emitting lasers (VCSELs) under dynamic operation was investigated by comparing the characteristics of VCSELs grown on (311)B and (100) GaAs substrates. Significantly larger suppression ratios of the two orthogonal polarization modes was obtained for VCSELs on (311)B substrates than those on (100) substrates under zero-bias modulation. Time-dependent orthogonal polarization suppression ratio measurements also showed that the polarization direction was more stable in the VCSEL on (311)B substrates than that on (100) substrates. Error-free transmission was realized from VCSELs on (311)B substrates with and without a polarizer in both back-to-back and 100-m multimode fiber transmission [ABSTRACT FROM PUBLISHER]