Jim A. Tatum

Reliability of various size oxide aperture VCSELs

This paper presents Honeywells most recent work on 850 nm oxide aperture vertical cavity surface emitting laser (VCSEL) reliability. The VCSELs studied have a range of aperture diameters from about 5 to 20 /spl mu/m and the reliability effect of aperture diameter is of principal interest in this paper. Larger apertures generally exhibit greater reliability. Electrostatic discharge (ESD) sensitivity thresholds of the various oxide aperture VCSELs is discussed, again showing dependence on diameter, with larger being better. Results for humidity exposure are presented. Here we find no aperture size dependence, because none of the tested designs show significant susceptibility to humidity-induced degradation. It is demonstrated that, in addition to end-of-life degradation, VCSELs generally exhibit variation of performance characteristics during the early part of operating life. This often leads to a requirement for device burn-in. Honeywells work in the area of wafer stabilization (trademarked under the name STABILAZE, patent pending) is introduced, showing how critical device parameters such as threshold and slope efficiency can be made to be unvarying over the products life without the need for costly component or module-level burn-ins.

Commercialization of Honeywell's VCSEL technology

In 1996, Honeywell was the first company to commercialize VCSEL technology, and today it is the worlds largest VCSEL component supplier. This paper will focus on the aspects of VCSEL manufacture that are important to maintain highly reliable and producible components. For current VCSEL products, we will address the evolution of VCSEL reliability and its effect on performance in data communications systems. New applications in both the data communications and sensor markets are being enabled by the VCSEL technology. This paper will also discuss new VCSEL structures, packages and wavelengths that are being commercialized by Honeywell to address these emerging markets.

Commercialization of Honeywell's VCSEL technology: further developments

Each year, more VCSEL technologies make the transition from research curiosities to commercially available products. In this paper we describe several such technologies at Honeywell, each at a different stage of that transition. Oxide-confined devices are already past the transition stage. We describe the generally excellent reliability of oxide-confined devices already in high-volume production, and compare it to results of the most recent-and possibly last-long-term reliability study of proton-implanted VCSELs. We report on detailed package-VCSEL interaction modeling, which is being used to improve performance and extend the life of common form-factor packages. We also note Honeywells progress toward commercialization of VCSELs and allied products at wavelengths other than 850 nm.

High-speed characteristics of VCSELs

The high speed characteristics of Vertical Cavity Surface Emitting Lasers (VCSELs) for use in modern high bandwidth fiber optical networks is presented. An equivalent circuit model based on microwave network analyzer S11 measurements is developed. The dynamic operation of multi- transverse mode VCSELs is also investigated. Experimentally, a laser with two orthogonally polarized modes is examined. We show that each of the transverse laser modes may have significantly different rise and fall times. A multimode rate equation model is used to predict the exact pulseshape for each mode. The laser gain is saturated by the total optical intensity, and the sum of the modal powers is shown to have a constant rise and fall time. The system performance in terms of the bit error rate is also investigated. We demonstrate that selective attenuation of the optical modes can lead to an increase in the bit error rate due to polarization partitioning noise.

A 56.1Gb/s NRZ modulated 850nm VCSEL-based optical link

We report a directly modulated 850nm VCSEL-based optical link operating at 56.1Gb/s (BER <; 1E-12). This is the highest modulation rate for a VCSEL-based link of any wavelength. An open eye is obtained at 60Gb/s.

A plot twist: the continuing story of VCSELs at AOC

During a year of substantial consolidation in the VCSEL industry, Honeywell sold their VCSEL Optical Products Division, which has now officially changed its name to Advanced Optical Components (AOC). Both manufacture and applied research continue, however. Some of the developments of the past year are discussed in this paper. They include advances in the understanding of VCSEL degradation physics, substantial improvements in long-wavelength VCSEL performance, and continuing progress in manufacturing technology. In addition, higher speed serial communications products, at 10 gigabits and particularly at 4 gigabits per second, have shown faster than predicted growth. We place these technologies and AOCs approach to them in a market perspective, along with other emerging applications.

The next generation of high speed VCSELs at Finisar

Commercial demand for optical transceivers operating at 14Gbps is now a reality. It is further expected that communications standards utilizing 850nm VCSELs at speeds up to 28Gbps will be ratified in the near future. We report on the development and productization of 850nm VCSELs for several applications, including high speed (both 14Gbps and 28Gbps) operation to support the continued fulfillment of data communication demand.

Long-wavelength VCSELs at Honeywell

In this paper we describe both the 1310 and 1550 nm VCSEL development work at Honeywell using both InP and GaAs substrates, and using both MOCVD and MBE. We describe the material systems, the designs, the growth techniques, and the promising results obtained and compare them to the needs of the communications industry. InGaAsN quantum well based VCSELs have been demonstrated to 1338 nm lasing at temperatures up to 90 C. Continuous wave InP based 1550 nm VCSELs have also been demonstrated.

VCSELs for 10 GB/s optical interconnects

This paper explores the use of vertical cavity surface emitting lasers (VCSEL) for optical interconnects operating at speeds of 10 GB/s and beyond. The application of 10 GB/s optical interconnects is being driven by both the data communications and the telecommunications industry, and the lines of demarcation in application are beginning to blur.

The VCSELs are coming

This paper describes the fabrication, operation, commercialization, and application of VCSELs operating at wavelength ranges from 650nm to 1600nm.