We have developed an 850nm VCSEL where current and photon confinement is achieved by a mesa structure without lateral oxidation. The VCSEL performance and reliability is discussed in the context of 4xFC and 10GbE applications.

Optically-pumped long-wavelength vertical-cavity surface-emitting lasers (VCSELs) have been fabricated exhibiting more than 2mW over 20–70°C, and 1.25mW at 85°C. Small-signal modulation measurements on the VCSEL at 20°C indicate a 3dB bandwidth of 14.8GHz at an output power of 2mW. The VCSELs have a narrow spectral width suitable for data transmission over single-mode fiber. The good temperature performance of the VCSEL is maintained in a suspended configuration that would allow monolithic integration.

Long-wavelength VCSELs have been fabricated that can operate uncooled up to 85°C and can be modulated up to 10 Gb/s data rates. Performance of these VCSELs will be discussed in the context of different applications.

Long wavelength VCSELs at 1300 nm have been developed to serve 10-Gigabit enterprise networks over FDDI grade multimode fibers up to 300 m in distance. The long wavelength VCSELs operate CW at temperatures over 100 °C. They are ideal low cost alternatives to DFB lasers for transceivers and transponders compatible with IEEE 10GBASE-LX4 or 10GBASE-LRM standards over multimode fibers.

We have implemented a coarse wavelength-division-multiplexing scheme based on uncooled long-wavelength vertical-cavity surface-emitting lasers (VCSELs) for 10-GbE transmission over 62.5-mm multimode fiber. Long-wavelength VCSELs were fabricated at the nominal wavelengths of 1275, 1300, 1325, and 1350 nm and integrated into a XENPAK module. Individual VCSELs require a drive current of 10 mA or less at 20/spl deg/C-85/spl deg/C.

Novel AlGalnAs VCSELs have been fabricated for coarse wavelength division multiplexing over multimode fibre at wavelengths of 1275, 1300, 1325 and 1350 nm. Efficient monomode lasing (>2.0 mW power, 31 % efficiency) and multimode lasing (up to 9 mW power, 39% efficiency) are reported-along with 3.125 and 10 Gbit/s modulation to 85degreesC.

The 1.31-mum AlGaInAs vertical-cavity surface-emitting lasers achieved efficient single-mode (SM) continuous-wave lasing at temperatures up to 120 degreesC, with 2.0-mW output power and 31% slope efficiency, as well as multimode (MM) lasing with up to 9-mW output power and up to 39% slope efficiency. High-speed modulation at data rates up to 10 Gb/s and transmission through different lengths of SM and MM fiber are demonstrated.

Optically-pumped long wavelength VCSELs emitting at 1.3 µm have been achieved in a compact format. Continuous-wave, single-mode lasing operation has been demonstrated with low lasing threshold, high output power, and a large SMSR over a wide range of operating temperatures.

Optobus is a ten channel parallel bi-directional datalink based on multimode fiber ribbons. The design represents a series of tradeoffs between cost and performance to produce a low cost interconnect solution with a minimum of 1.5 Gbit/s of aggregate throughput

The use of vertical cavity surface emitting lasers (VCSELs) in a parallel optical interconnect for Motorola's OPTOBUSTM interconnect was made public over 1 year ago. This was the first time VCSELs were introduced into a product which took advantage of the excellent qualities of VCSELs over edge-emitting lasers. Motorola's OPTOBUSTM interconnect is a ten channel parallel bi-directional data link based on two 10 channel multimode fiber ribbons. One of the key differences in this type of interconnect compared with previous data link designs is the use of the VCSELs as the optical source for the link's fiber optic transmitter. A single 1 X 10 VCSEL array from a GaAs wafer is die attached to a 10 channel GUIDECASTTM optical interface unit which couples the emission from each laser device to its corresponding fiber ribbon channel and thus negates the use of expensive manufacturing techniques such as active alignment and pig-tailing. The OPTOBUSTM interconnect achieves its performance goals (which include low cost) via the unique characteristics of the GaAs VCSELs arrays. For example, the 850 nm devices produce a circular symmetric beam with a half angle of about 10 degrees allowing the coupling loss into the waveguide to be less than 3 dB. In addition, to maintain low manufacturing costs, each VCSEL array is individually and automatically probe tested (just as in the silicon industry) to verify that each VCSEL achieves the OPTOBUSTM interconnect's stringent electrical, optical, thermal and mechanical specifications. Typical computer generated wafer maps from automated production tooling and statistical parametric results are discussed. The combination of low threshold currents with superior thermal and optical performance allow the devices to be modulated under fixed bias conditions. Typical drive currents of 3X threshold are used to obtain nominal FDA Class 1 safety optical power levels from the GUIDECASTTM optical interface unit.

The use of vertical cavity surface emitting lasers (VCSELs)in a parallel optical interconnect for Motorola's OPTOBUSTM interconnect was made public over 1 year ago. This was the first time VCSELs were introduced into a product which took advantage of the excellent qualities of VCSELs over edge-emitting lasers. Motorola's OPTOBUSTM interconnect is a ten channel parallel bi-directional data link based on two 10 channel multimode fiber ribbons. One of the key differences in this type of interconnect compared with previous data link designs is the use of the VCSELs as the optical source for the link's fiber optic transmitter. A single 1×10 VCSEL array from a GaAs wafer is die attached to a 10 channel GUIDECASTTM optical interface unit which couples the emission from each laser device to its corresponding fiber ribbon channel and thus negates the use of expensive manufacturing techniques such as active alignment and pigtailing. The OPTOBUSTM interconnect achieves its performance goals (which include low cost) via the unique characteristics of the GaAs VCSELs arrays. For example, the 850 nm devices produce a circular symmetric beam with a half angle of about 10 degrees allowing the coupling loss into the waveguide to be less than 3 dB. In addition, to maintain low manufacturing costs, each VCSEL array is individually and automatically probe tested (just as in the silicon industry) to verify that each VCSEL achieves the OPTOBUSTM interconnect's stringent electrical, optical, thermal and mechanical specifications. Typical computer generated wafer maps from automated production tooling and statistical parametric results are discussed. The combination of low threshold currents with superior thermal and optical performance allow the devices to be modulated under fixed bias conditions. Typical drive currents of 3X threshold are used to obtain nominal FDA Class 1 safety optical power levels from the GUIDECASTTM optical interface unit

Strained-layer quantum-well lasers, when operated at moderate injection levels, are known to exhibit a reduced linewidth enhancement factor, alpha, an important parameter in the design of semiconductor lasers. Under increased loss conditions, when spill-over of carriers into the barrier becomes significant, they can also be operated in a quasi-double-heterostructure mode at the barrier wavelength. Thus, by proper control of loss, lasing at different wavelengths is possible, at least in principle. An investigation has been carried out to determine explicitly the spectral dependence of the differential gain, spectral shift, and alpha of narrow-stripe InGaAs-GaAs separate-confinement strained-layer single-quantum-well laser operated near the wavelength of the GaAs barrier under extremely high injection. Despite the carrier spill-over, alpha was found to be remarkably low being about 1.7 at the spectral gain peak (877 nm), which was also the lasing wavelength.

A maskless selective diffusion of silicon into GaAs is achieved by the selective modification of the GaAs surface using low energy Ar sputtering. The Ga rich surface resulting from the Ar sputtering prevents the diffusion of silicon into GaAs.

Measurements of the current/voltage characteristics and electroluminescence spectra of nipi LEDs with selectively diffused contacts have been performed over the temperature range 3-300 K. Good correlation has been observed between the forward characteristics of the diodes and the tuning of the electroluminescence. Analysis of the I/V characteristics indicates that the recombination occurs by electron tunnelling through the parabolic potential barriers.

The lateral refractive index step Δn in GaAs/AlGaAs multiple quantum well waveguides fabricated by impurity-induced disordering is determined. Δn is found to depend on polarization and wavelength, increasing towards the active-layer band gap. The lateral index step can be as large as 4×10−2 for a Zn disordered waveguide device at 875 nm. A strong birefringence of the waveguiding characteristics is observed leading to an antiguiding behavior of TM-polarized light for wavelengths sufficiently below the band gap.

Intrinsic phase matching between a TE and a TM mode is obtained in a GaAs/AlGaAs superlattice waveguide, fabricated by Zn diffusion induced disordering, as a result of the birefringent waveguiding properties of the superlattice in combination with a proper choice of the waveguide geometry. As a consequence, up to 90% polarisation conversion is demonstrated without the application of phase matching...

A surface emitting AlGaAs/GaAs DH laser having one etched facet integrated with a 45 degrees metallised reflector is demonstrated with a threshold current as low as 70 mA for a 6 mu m (gain-guided) shallow mesa stripe geometry. The etched facet/45 degrees mirror combination was fabricated by tilted ion beam milling through the p-metallisation of the processed wafer. A surface emitter with power as...

GaAs/AlGaAs light-emitting diodes (LED’s) with nipi active regions have been successfully fabricated using sequential n and p diffusions to selectively contact the doping superlattice. By doing sequential patterned sulfur and zinc diffusions, a lateral injection LED can be readily fabricated. Excellent current-voltage characteristics were achieved with reverse breakdown voltages in excess of 9.5 V, indicating that the selective contacts were nearly optimum. cw outputs of 500 μW at 50 mA drive current have been observed. The LED output spectrum was seen to tune with applied bias at a rate of about 650 meV/V at low temperatures.